up teams work

.gitea/workflows/feedser-ci.yml

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+name: Feedser CI
+
+on:
+  push:
+    branches: ["main", "develop"]
+  pull_request:
+    branches: ["main", "develop"]
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Setup .NET 10 preview
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 10.0.100-rc.1.25451.107
+          include-prerelease: true
+
+      - name: Restore dependencies
+        run: dotnet restore src/StellaOps.Feedser/StellaOps.Feedser.sln
+
+      - name: Build
+        run: dotnet build src/StellaOps.Feedser/StellaOps.Feedser.sln --configuration Release --no-restore -warnaserror
+
+      - name: Test
+        run: dotnet test src/StellaOps.Feedser/StellaOps.Feedser.Tests/StellaOps.Feedser.Tests.csproj --configuration Release --no-restore --logger "trx;LogFileName=feedser-tests.trx"

.gitea/workflows/feedser-tests.yml

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+name: Feedser Tests CI
+
+on:
+  push:
+    paths:
+      - 'StellaOps.Feedser/**'
+      - '.gitea/workflows/feedser-tests.yml'
+  pull_request:
+    paths:
+      - 'StellaOps.Feedser/**'
+      - '.gitea/workflows/feedser-tests.yml'
+
+jobs:
+  advisory-store-performance:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up .NET SDK
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 10.0.100-rc.1
+
+      - name: Restore dependencies
+        working-directory: StellaOps.Feedser
+        run: dotnet restore StellaOps.Feedser.Tests/StellaOps.Feedser.Tests.csproj
+
+      - name: Run advisory store performance test
+        working-directory: StellaOps.Feedser
+        run: |
+          set -euo pipefail
+          dotnet test \
+            StellaOps.Feedser.Tests/StellaOps.Feedser.Tests.csproj \
+            --filter "FullyQualifiedName~AdvisoryStorePerformanceTests" \
+            --logger:"console;verbosity=detailed" | tee performance.log
+
+      - name: Upload performance log
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: advisory-store-performance-log
+          path: StellaOps.Feedser/performance.log
+
+  full-test-suite:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up .NET SDK
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 10.0.100-rc.1
+
+      - name: Restore dependencies
+        working-directory: StellaOps.Feedser
+        run: dotnet restore StellaOps.Feedser.Tests/StellaOps.Feedser.Tests.csproj
+
+      - name: Run full test suite with baseline guard
+        working-directory: StellaOps.Feedser
+        env:
+          BASELINE_SECONDS: "19.8"
+          TOLERANCE_PERCENT: "25"
+        run: |
+          set -euo pipefail
+          start=$(date +%s)
+          dotnet test StellaOps.Feedser.Tests/StellaOps.Feedser.Tests.csproj --no-build | tee full-tests.log
+          end=$(date +%s)
+          duration=$((end-start))
+          echo "Full test duration: ${duration}s"
+          export DURATION_SECONDS="$duration"
+          python - <<'PY'
+import os, sys
+duration = float(os.environ["DURATION_SECONDS"])
+baseline = float(os.environ["BASELINE_SECONDS"])
+tolerance = float(os.environ["TOLERANCE_PERCENT"])
+threshold = baseline * (1 + tolerance / 100)
+print(f"Baseline {baseline:.1f}s, threshold {threshold:.1f}s, observed {duration:.1f}s")
+if duration > threshold:
+    sys.exit(f"Full test duration {duration:.1f}s exceeded threshold {threshold:.1f}s")
+PY
+
+      - name: Upload full test log
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: full-test-suite-log
+          path: StellaOps.Feedser/full-tests.log

src/Jobs.cs

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+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using StellaOps.Feedser.Core.Jobs;
+
+namespace StellaOps.Feedser.Source.Vndr.Oracle;
+
+internal static class OracleJobKinds
+{
+    public const string Fetch = "source:vndr-oracle:fetch";
+    public const string Parse = "source:vndr-oracle:parse";
+    public const string Map = "source:vndr-oracle:map";
+}
+
+internal sealed class OracleFetchJob : IJob
+{
+    private readonly OracleConnector _connector;
+
+    public OracleFetchJob(OracleConnector connector)
+        => _connector = connector ?? throw new ArgumentNullException(nameof(connector));
+
+    public Task ExecuteAsync(JobExecutionContext context, CancellationToken cancellationToken)
+        => _connector.FetchAsync(context.Services, cancellationToken);
+}
+
+internal sealed class OracleParseJob : IJob
+{
+    private readonly OracleConnector _connector;
+
+    public OracleParseJob(OracleConnector connector)
+        => _connector = connector ?? throw new ArgumentNullException(nameof(connector));
+
+    public Task ExecuteAsync(JobExecutionContext context, CancellationToken cancellationToken)
+        => _connector.ParseAsync(context.Services, cancellationToken);
+}
+
+internal sealed class OracleMapJob : IJob
+{
+    private readonly OracleConnector _connector;
+
+    public OracleMapJob(OracleConnector connector)
+        => _connector = connector ?? throw new ArgumentNullException(nameof(connector));
+
+    public Task ExecuteAsync(JobExecutionContext context, CancellationToken cancellationToken)
+        => _connector.MapAsync(context.Services, cancellationToken);
+}

src/OracleConnector.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using MongoDB.Bson;
+using StellaOps.Feedser.Source.Common;
+using StellaOps.Feedser.Source.Common.Fetch;
+using StellaOps.Feedser.Source.Vndr.Oracle.Configuration;
+using StellaOps.Feedser.Source.Vndr.Oracle.Internal;
+using StellaOps.Feedser.Storage.Mongo;
+using StellaOps.Feedser.Storage.Mongo.Advisories;
+using StellaOps.Feedser.Storage.Mongo.Documents;
+using StellaOps.Feedser.Storage.Mongo.Dtos;
+using StellaOps.Feedser.Storage.Mongo.PsirtFlags;
+using StellaOps.Plugin;
+
+namespace StellaOps.Feedser.Source.Vndr.Oracle;
+
+public sealed class OracleConnector : IFeedConnector
+{
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull,
+    };
+
+    private readonly SourceFetchService _fetchService;
+    private readonly RawDocumentStorage _rawDocumentStorage;
+    private readonly IDocumentStore _documentStore;
+    private readonly IDtoStore _dtoStore;
+    private readonly IAdvisoryStore _advisoryStore;
+    private readonly IPsirtFlagStore _psirtFlagStore;
+    private readonly ISourceStateRepository _stateRepository;
+    private readonly OracleOptions _options;
+    private readonly TimeProvider _timeProvider;
+    private readonly ILogger<OracleConnector> _logger;
+
+    public OracleConnector(
+        SourceFetchService fetchService,
+        RawDocumentStorage rawDocumentStorage,
+        IDocumentStore documentStore,
+        IDtoStore dtoStore,
+        IAdvisoryStore advisoryStore,
+        IPsirtFlagStore psirtFlagStore,
+        ISourceStateRepository stateRepository,
+        IOptions<OracleOptions> options,
+        TimeProvider? timeProvider,
+        ILogger<OracleConnector> logger)
+    {
+        _fetchService = fetchService ?? throw new ArgumentNullException(nameof(fetchService));
+        _rawDocumentStorage = rawDocumentStorage ?? throw new ArgumentNullException(nameof(rawDocumentStorage));
+        _documentStore = documentStore ?? throw new ArgumentNullException(nameof(documentStore));
+        _dtoStore = dtoStore ?? throw new ArgumentNullException(nameof(dtoStore));
+        _advisoryStore = advisoryStore ?? throw new ArgumentNullException(nameof(advisoryStore));
+        _psirtFlagStore = psirtFlagStore ?? throw new ArgumentNullException(nameof(psirtFlagStore));
+        _stateRepository = stateRepository ?? throw new ArgumentNullException(nameof(stateRepository));
+        _options = (options ?? throw new ArgumentNullException(nameof(options))).Value ?? throw new ArgumentNullException(nameof(options));
+        _options.Validate();
+        _timeProvider = timeProvider ?? TimeProvider.System;
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public string SourceName => VndrOracleConnectorPlugin.SourceName;
+
+    public async Task FetchAsync(IServiceProvider services, CancellationToken cancellationToken)
+    {
+        var cursor = await GetCursorAsync(cancellationToken).ConfigureAwait(false);
+        var pendingDocuments = cursor.PendingDocuments.ToList();
+        var pendingMappings = cursor.PendingMappings.ToList();
+        var now = _timeProvider.GetUtcNow();
+
+        foreach (var uri in _options.AdvisoryUris)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            try
+            {
+                var advisoryId = DeriveAdvisoryId(uri);
+                var title = advisoryId.Replace('-', ' ');
+                var published = now;
+
+                var metadata = OracleDocumentMetadata.CreateMetadata(advisoryId, title, published);
+                var existing = await _documentStore.FindBySourceAndUriAsync(SourceName, uri.ToString(), cancellationToken).ConfigureAwait(false);
+
+                var request = new SourceFetchRequest(OracleOptions.HttpClientName, SourceName, uri)
+                {
+                    Metadata = metadata,
+                    ETag = existing?.Etag,
+                    LastModified = existing?.LastModified,
+                    AcceptHeaders = new[] { "text/html", "application/xhtml+xml", "text/plain;q=0.5" },
+                };
+
+                var result = await _fetchService.FetchAsync(request, cancellationToken).ConfigureAwait(false);
+                if (!result.IsSuccess || result.Document is null)
+                {
+                    continue;
+                }
+
+                if (!pendingDocuments.Contains(result.Document.Id))
+                {
+                    pendingDocuments.Add(result.Document.Id);
+                }
+
+                if (_options.RequestDelay > TimeSpan.Zero)
+                {
+                    await Task.Delay(_options.RequestDelay, cancellationToken).ConfigureAwait(false);
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Oracle fetch failed for {Uri}", uri);
+                await _stateRepository.MarkFailureAsync(SourceName, _timeProvider.GetUtcNow(), TimeSpan.FromMinutes(10), ex.Message, cancellationToken).ConfigureAwait(false);
+                throw;
+            }
+        }
+
+        var updatedCursor = cursor
+            .WithPendingDocuments(pendingDocuments)
+            .WithPendingMappings(pendingMappings)
+            .WithLastProcessed(now);
+
+        await UpdateCursorAsync(updatedCursor, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task ParseAsync(IServiceProvider services, CancellationToken cancellationToken)
+    {
+        var cursor = await GetCursorAsync(cancellationToken).ConfigureAwait(false);
+        if (cursor.PendingDocuments.Count == 0)
+        {
+            return;
+        }
+
+        var pendingDocuments = cursor.PendingDocuments.ToList();
+        var pendingMappings = cursor.PendingMappings.ToList();
+
+        foreach (var documentId in cursor.PendingDocuments)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            var document = await _documentStore.FindAsync(documentId, cancellationToken).ConfigureAwait(false);
+            if (document is null)
+            {
+                pendingDocuments.Remove(documentId);
+                pendingMappings.Remove(documentId);
+                continue;
+            }
+
+            if (!document.GridFsId.HasValue)
+            {
+                _logger.LogWarning("Oracle document {DocumentId} missing GridFS payload", document.Id);
+                await _documentStore.UpdateStatusAsync(document.Id, DocumentStatuses.Failed, cancellationToken).ConfigureAwait(false);
+                pendingDocuments.Remove(documentId);
+                pendingMappings.Remove(documentId);
+                continue;
+            }
+
+            OracleDto dto;
+            try
+            {
+                var metadata = OracleDocumentMetadata.FromDocument(document);
+                var content = await _rawDocumentStorage.DownloadAsync(document.GridFsId.Value, cancellationToken).ConfigureAwait(false);
+                var html = System.Text.Encoding.UTF8.GetString(content);
+                dto = OracleParser.Parse(html, metadata);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Oracle parse failed for document {DocumentId}", document.Id);
+                await _documentStore.UpdateStatusAsync(document.Id, DocumentStatuses.Failed, cancellationToken).ConfigureAwait(false);
+                pendingDocuments.Remove(documentId);
+                pendingMappings.Remove(documentId);
+                continue;
+            }
+
+            var json = JsonSerializer.Serialize(dto, SerializerOptions);
+            var payload = BsonDocument.Parse(json);
+            var validatedAt = _timeProvider.GetUtcNow();
+
+            var existingDto = await _dtoStore.FindByDocumentIdAsync(document.Id, cancellationToken).ConfigureAwait(false);
+            var dtoRecord = existingDto is null
+                ? new DtoRecord(Guid.NewGuid(), document.Id, SourceName, "oracle.advisory.v1", payload, validatedAt)
+                : existingDto with
+                {
+                    Payload = payload,
+                    SchemaVersion = "oracle.advisory.v1",
+                    ValidatedAt = validatedAt,
+                };
+
+            await _dtoStore.UpsertAsync(dtoRecord, cancellationToken).ConfigureAwait(false);
+            await _documentStore.UpdateStatusAsync(document.Id, DocumentStatuses.PendingMap, cancellationToken).ConfigureAwait(false);
+
+            pendingDocuments.Remove(documentId);
+            if (!pendingMappings.Contains(documentId))
+            {
+                pendingMappings.Add(documentId);
+            }
+        }
+
+        var updatedCursor = cursor
+            .WithPendingDocuments(pendingDocuments)
+            .WithPendingMappings(pendingMappings);
+
+        await UpdateCursorAsync(updatedCursor, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task MapAsync(IServiceProvider services, CancellationToken cancellationToken)
+    {
+        var cursor = await GetCursorAsync(cancellationToken).ConfigureAwait(false);
+        if (cursor.PendingMappings.Count == 0)
+        {
+            return;
+        }
+
+        var pendingMappings = cursor.PendingMappings.ToList();
+
+        foreach (var documentId in cursor.PendingMappings)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            var dtoRecord = await _dtoStore.FindByDocumentIdAsync(documentId, cancellationToken).ConfigureAwait(false);
+            var document = await _documentStore.FindAsync(documentId, cancellationToken).ConfigureAwait(false);
+
+            if (dtoRecord is null || document is null)
+            {
+                pendingMappings.Remove(documentId);
+                continue;
+            }
+
+            OracleDto? dto;
+            try
+            {
+                var json = dtoRecord.Payload.ToJson();
+                dto = JsonSerializer.Deserialize<OracleDto>(json, SerializerOptions);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Oracle DTO deserialization failed for document {DocumentId}", documentId);
+                await _documentStore.UpdateStatusAsync(document.Id, DocumentStatuses.Failed, cancellationToken).ConfigureAwait(false);
+                pendingMappings.Remove(documentId);
+                continue;
+            }
+
+            if (dto is null)
+            {
+                _logger.LogWarning("Oracle DTO payload deserialized as null for document {DocumentId}", documentId);
+                await _documentStore.UpdateStatusAsync(document.Id, DocumentStatuses.Failed, cancellationToken).ConfigureAwait(false);
+                pendingMappings.Remove(documentId);
+                continue;
+            }
+
+            var mappedAt = _timeProvider.GetUtcNow();
+            var (advisory, flag) = OracleMapper.Map(dto, SourceName, mappedAt);
+            await _advisoryStore.UpsertAsync(advisory, cancellationToken).ConfigureAwait(false);
+            await _psirtFlagStore.UpsertAsync(flag, cancellationToken).ConfigureAwait(false);
+            await _documentStore.UpdateStatusAsync(document.Id, DocumentStatuses.Mapped, cancellationToken).ConfigureAwait(false);
+
+            pendingMappings.Remove(documentId);
+        }
+
+        var updatedCursor = cursor.WithPendingMappings(pendingMappings);
+        await UpdateCursorAsync(updatedCursor, cancellationToken).ConfigureAwait(false);
+    }
+
+    private async Task<OracleCursor> GetCursorAsync(CancellationToken cancellationToken)
+    {
+        var record = await _stateRepository.TryGetAsync(SourceName, cancellationToken).ConfigureAwait(false);
+        return OracleCursor.FromBson(record?.Cursor);
+    }
+
+    private async Task UpdateCursorAsync(OracleCursor cursor, CancellationToken cancellationToken)
+    {
+        var completedAt = _timeProvider.GetUtcNow();
+        await _stateRepository.UpdateCursorAsync(SourceName, cursor.ToBsonDocument(), completedAt, cancellationToken).ConfigureAwait(false);
+    }
+
+    private static string DeriveAdvisoryId(Uri uri)
+    {
+        var segments = uri.Segments;
+        if (segments.Length == 0)
+        {
+            return uri.AbsoluteUri;
+        }
+
+        var slug = segments[^1].Trim('/');
+        if (string.IsNullOrWhiteSpace(slug))
+        {
+            return uri.AbsoluteUri;
+        }
+
+        return slug.Replace('.', '-');
+    }
+}

src/OracleConnectorPlugin.cs

@@ -0,0 +1,21 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using StellaOps.Plugin;
+
+namespace StellaOps.Feedser.Source.Vndr.Oracle;
+
+public sealed class VndrOracleConnectorPlugin : IConnectorPlugin
+{
+    public const string SourceName = "vndr-oracle";
+
+    public string Name => SourceName;
+
+    public bool IsAvailable(IServiceProvider services)
+        => services.GetService<OracleConnector>() is not null;
+
+    public IFeedConnector Create(IServiceProvider services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        return services.GetRequiredService<OracleConnector>();
+    }
+}

src/OracleDependencyInjectionRoutine.cs

@@ -0,0 +1,54 @@
+using System;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using StellaOps.DependencyInjection;
+using StellaOps.Feedser.Core.Jobs;
+using StellaOps.Feedser.Source.Vndr.Oracle.Configuration;
+
+namespace StellaOps.Feedser.Source.Vndr.Oracle;
+
+public sealed class OracleDependencyInjectionRoutine : IDependencyInjectionRoutine
+{
+    private const string ConfigurationSection = "feedser:sources:oracle";
+
+    public IServiceCollection Register(IServiceCollection services, IConfiguration configuration)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(configuration);
+
+        services.AddOracleConnector(options =>
+        {
+            configuration.GetSection(ConfigurationSection).Bind(options);
+            options.Validate();
+        });
+
+        services.AddTransient<OracleFetchJob>();
+        services.AddTransient<OracleParseJob>();
+        services.AddTransient<OracleMapJob>();
+
+        services.PostConfigure<JobSchedulerOptions>(options =>
+        {
+            EnsureJob(options, OracleJobKinds.Fetch, typeof(OracleFetchJob));
+            EnsureJob(options, OracleJobKinds.Parse, typeof(OracleParseJob));
+            EnsureJob(options, OracleJobKinds.Map, typeof(OracleMapJob));
+        });
+
+        return services;
+    }
+
+    private static void EnsureJob(JobSchedulerOptions options, string kind, Type jobType)
+    {
+        if (options.Definitions.ContainsKey(kind))
+        {
+            return;
+        }
+
+        options.Definitions[kind] = new JobDefinition(
+            kind,
+            jobType,
+            options.DefaultTimeout,
+            options.DefaultLeaseDuration,
+            CronExpression: null,
+            Enabled: true);
+    }
+}

src/StellaOps.Feedser/AGENTS.md

@@ -0,0 +1,128 @@
+## Autonomous Agent Instructions
+
+Before you act you need to read `/src/StellaOps.Feedser/AGENTS.md` files `AGENTS.md`,`TASKS.md` in each working directory I gave you.
+
+Boundaries:
+- You operate only in the working directories I gave you, unless there is dependencies that makes you to work on dependency in shared directory. Then you ask for confirmation.
+
+Do:
+- Keep endpoints small, deterministic, and cancellation-aware.
+- Improve logs/metrics as per tasks.
+- Update `TASKS.md` when moving tasks forward.
+- When you are done with all task you state explicitly you are done.
+- Impersonate the role described on working directory `AGENTS.md` you will read, if role is not available - take role of the CTO of the StellaOps in early stages.
+
+Output:
+- Summary of changes and any cross-module requests.
+
+# StellaOps — Agent Operations Guide (Master)
+
+> Purpose: Orient all human + autonomous agents to the StellaOps platform, its data flows, component boundaries, and rules of engagement so teams can work **in parallel on the same branch** with minimal contention.
+
+---
+
+## 1) What is StellaOps?
+
+**StellaOps** is a sovereign/offline-first container & infrastructure security platform. Its core loop:
+
+1. **Intelligence** — Ingest vulnerability advisories from primary sources.
+2. **Normalization & Merge** — Reconcile into a canonical, deduplicated database with deterministic precedence.
+3. **Distribution** — Export a Trivy-compatible database (OCI artifact) and optional vuln-list JSON for self-hosted scanners.
+4. **Scanning & Policy** — Scanners consume that DB; policy engines gate deployments; artifacts may be signed downstream.
+
+This repository’s focus is the **Feedser** service (ingest/merge/export).
+
+---
+
+## 2) High‑level architecture (technical overview)
+
+```
+
+```
+    [Primary Sources: NVD, GHSA/OSV, Distros, PSIRTs, CERTs, KEV, ICS]
+                             │
+                  (Fetch + Validate DTOs)
+                             ▼
+               [Normalizer → Canonical Advisory]
+                             │
+                 (Alias graph + Precedence)
+                             ▼
+                [Feed‑Merge Store (MongoDB)]
+                             │
+              ┌──────────────┴──────────────┐
+              ▼                             ▼
+[Export: vuln‑list JSON]         [Packager: Trivy DB (OCI)]
+              │                             │
+              └────────────►  Distribution (ORAS / offline bundle)
+```
+
+```
+
+**Key invariants**
+
+- **Deterministic**: same inputs → same canonical JSON → same export digests.
+- **Precedence**: **distro OVAL/PSIRT > NVD** for OS packages; **KEV only flags exploitation**; regional CERTs enrich text/refs.
+- **Provenance** everywhere: source document, extraction method (`parser|llm`), and timestamps.
+
+You have to read `./ARCHITECTURE.md` for more information.
+---
+
+## 4) Main agents (roles, interactions, scope)
+
+- **BE‑Base (Platform & Pipeline)**  
+  Owns DI, plugin host, job scheduler/coordinator, configuration binding, minimal API endpoints, and Mongo bootstrapping.
+- **BE‑Conn‑X (Connectors)**  
+  One agent per source family (NVD, Red Hat, Ubuntu, Debian, SUSE, GHSA, OSV, PSIRTs, CERTs, KEV, ICS). Implements fetch/parse/map with incremental watermarks.
+- **BE‑Merge (Canonical Merge & Dedupe)**  
+  Identity graph, precedence policies, canonical JSON serializer, and deterministic hashing (`merge_event`).
+- **BE‑Export (JSON & Trivy DB)**  
+  Deterministic export trees, Trivy DB packaging, optional ORAS push, and offline bundle.
+- **QA (Validation & Observability)**  
+  Schema tests, fixture goldens, determinism checks, metrics/logs/traces, e2e reproducibility runs.
+- **DevEx/Docs**  
+  Maintains this agent framework, templates, and per‑directory guides; assists parallelization and reviews.
+
+**Interaction sketch**
+
+- Connectors → **Core** jobs → **Storage.Mongo**
+- **Merge** refines canonical records; **Exporters** read canonical data to produce artifacts
+- **QA** spans all layers with fixtures/metrics and determinism checks
+
+---
+
+## 5) Key technologies & integrations
+
+- **Runtime**: .NET 10 (`net10.0`) preview SDK; C# latest preview features.
+- **Data**: MongoDB (canonical store and job/export state).
+- **Packaging**: Trivy DB (BoltDB inside `db.tar.gz`), vuln‑list JSON (optional), ORAS for OCI push.
+- **Observability**: structured logs, counters, and (optional) OpenTelemetry traces.
+- **Ops posture**: offline‑first, allowlist for remote hosts, strict schema validation, gated LLM fallback (only where explicitly configured).
+
+---
+
+## 6) Data flow (end‑to‑end)
+
+1. **Fetch**: connectors request source windows with retries/backoff, persist raw documents with SHA256/ETag metadata.
+2. **Parse**: validate to DTOs (schema‑checked), quarantine failures.
+3. **Map**: normalize to canonical advisories (aliases, affected ranges with NEVRA/EVR/SemVer, references, provenance).
+4. **Merge**: enforce precedence and determinism; track before/after hashes.
+5. **Export**: JSON tree and/or Trivy DB; package and (optionally) push; write export state.
+
+---
+
+## 7) Work-in-parallel rules (important)
+
+- **Directory ownership**: Each agent works **only inside its module directory**. Cross‑module edits require a brief handshake in issues/PR description.
+- **Scoping**: Use each module’s `AGENTS.md` and `TASKS.md` to plan; autonomous agents must read `src/AGENTS.md` and the module docs before acting.
+- **Determinism**: Sort keys, normalize timestamps to UTC ISO‑8601, avoid non‑deterministic data in exports and tests.
+- **Status tracking**: Update your module’s `TASKS.md` as you progress (TODO → DOING → DONE/BLOCKED).
+- **Tests**: Add/extend fixtures and unit tests per change; never regress determinism or precedence.
+
+---
+
+## 8) Glossary (quick)
+
+- **OVAL** — Vendor/distro security definition format; authoritative for OS packages.
+- **NEVRA / EVR** — RPM and Debian version semantics for OS packages.
+- **PURL / SemVer** — Coordinates and version semantics for OSS ecosystems.
+- **KEV** — Known Exploited Vulnerabilities (flag only).

src/StellaOps.Feedser/ARCHITECTURE.md

@@ -0,0 +1,191 @@
+@ -1,191 +0,0 @@
+# ARCHITECTURE.md — **StellaOps.Feedser**
+
+> **Goal**: Build a sovereign-ready, self-hostable **feed-merge service** that ingests authoritative vulnerability sources, normalizes and de-duplicates them into **MongoDB**, and exports **JSON** and **Trivy-compatible DB** artifacts.
+> **Form factor**: Long-running **Web Service** with **REST APIs** (health, status, control) and an embedded **internal cron scheduler**.
+> **No signing inside Feedser** (signing is a separate pipeline step).
+> **Runtime SDK baseline**: .NET 10 Preview 7 (SDK 10.0.100-preview.7.25380.108) targeting `net10.0`, aligned with the deployed api.stella-ops.org service.
+> **Three explicit stages**:
+>
+> 1. **Source Download** → raw documents.
+> 2. **Merge + Dedupe + Normalization** → MongoDB canonical.
+> 3. **Export** → JSON or TrivyDB (full or delta), then (externally) sign/publish.
+
+---
+
+## 1) Naming & Solution Layout
+
+**Solution root**: `StellaOps.Feedser`
+**Source connectors** namespace prefix: `StellaOps.Feedser.Source.*`
+**Exporters**:
+
+* `StellaOps.Feedser.Exporter.Json`
+* `StellaOps.Feedser.Exporter.TrivyDb`
+
+**Projects** (`/src`):
+
+```
+StellaOps.Feedser.WebService/        # ASP.NET Core (Minimal API, net10.0 preview) WebService + embedded scheduler
+StellaOps.Feedser.Core/              # Domain models, pipelines, merge/dedupe engine, jobs orchestration
+StellaOps.Feedser.Models/            # Canonical POCOs, JSON Schemas, enums
+StellaOps.Feedser.Storage.Mongo/     # Mongo repositories, GridFS access, indexes, resume "flags"
+StellaOps.Feedser.Source.Common/     # HTTP clients, rate-limiters, schema validators, parsers utils
+StellaOps.Feedser.Source.Cve/
+StellaOps.Feedser.Source.Nvd/
+StellaOps.Feedser.Source.Ghsa/
+StellaOps.Feedser.Source.Osv/
+StellaOps.Feedser.Source.Jvn/
+StellaOps.Feedser.Source.CertCc/
+StellaOps.Feedser.Source.Kev/
+StellaOps.Feedser.Source.Kisa/
+StellaOps.Feedser.Source.CertIn/
+StellaOps.Feedser.Source.CertFr/
+StellaOps.Feedser.Source.CertBund/
+StellaOps.Feedser.Source.Acsc/
+StellaOps.Feedser.Source.Cccs/
+StellaOps.Feedser.Source.Ru.Bdu/     # HTML→schema with LLM fallback (gated)
+StellaOps.Feedser.Source.Ru.Nkcki/   # PDF/HTML bulletins → structured
+StellaOps.Feedser.Source.Vndr.Msrc/
+StellaOps.Feedser.Source.Vndr.Cisco/
+StellaOps.Feedser.Source.Vndr.Oracle/
+StellaOps.Feedser.Source.Vndr.Adobe/
+StellaOps.Feedser.Source.Vndr.Apple/
+StellaOps.Feedser.Source.Vndr.Chromium/
+StellaOps.Feedser.Source.Vndr.Vmware/
+StellaOps.Feedser.Source.Distro.RedHat/
+StellaOps.Feedser.Source.Distro.Ubuntu/
+StellaOps.Feedser.Source.Distro.Debian/
+StellaOps.Feedser.Source.Distro.Suse/
+StellaOps.Feedser.Source.Ics.Cisa/
+StellaOps.Feedser.Source.Ics.Kaspersky/
+StellaOps.Feedser.Normalization/     # Canonical mappers, validators, version-range normalization
+StellaOps.Feedser.Merge/             # Identity graph, precedence, deterministic merge
+StellaOps.Feedser.Exporter.Json/
+StellaOps.Feedser.Exporter.TrivyDb/
+StellaOps.Feedser.Tests/             # Unit, component, integration & golden fixtures
+```
+
+---
+
+## 2) Runtime Shape
+
+**Process**: single service (`StellaOps.Feedser.WebService`)
+
+* `Program.cs`: top-level entry using **Generic Host**, **DI**, **Options** binding from `appsettings.json` + environment + optional `feedser.yaml`.
+* Built-in **scheduler** (cron-like) + **job manager** with **distributed locks** in Mongo to prevent overlaps, enforce timeouts, allow cancel/kill.
+* **REST APIs** for health/readiness/progress/trigger/kill/status.
+
+**Key NuGet concepts** (indicative): `MongoDB.Driver`, `Polly` (retry/backoff), `System.Threading.Channels`, `Microsoft.Extensions.Http`, `Microsoft.Extensions.Hosting`, `Serilog`, `OpenTelemetry`.
+
+---
+
+## 3) Data Storage — **MongoDB** (single source of truth)
+
+**Database**: `feedser`
+**Write concern**: `majority` for merge/export state, `acknowledged` for raw docs.
+**Collections** (with “flags”/resume points):
+
+* `source`
+  * `_id`, `name`, `type`, `baseUrl`, `auth`, `notes`.
+* `source_state`
+  * Keys: `sourceName` (unique), `enabled`, `cursor`, `lastSuccess`, `failCount`, `backoffUntil`, `paceOverrides`, `paused`.
+  * Drives incremental fetch/parse/map resume and operator pause/pace controls.
+* `document`
+  * `_id`, `sourceName`, `uri`, `fetchedAt`, `sha256`, `contentType`, `status`, `metadata`, `gridFsId`, `etag`, `lastModified`.
+  * Index `{sourceName:1, uri:1}` unique; optional TTL for superseded versions.
+* `dto`
+  * `_id`, `sourceName`, `documentId`, `schemaVer`, `payload` (BSON), `validatedAt`.
+  * Index `{sourceName:1, documentId:1}`.
+* `advisory`
+  * `_id`, `advisoryKey`, `title`, `summary`, `lang`, `published`, `modified`, `severity`, `exploitKnown`.
+  * Unique `{advisoryKey:1}` plus indexes on `modified` and `published`.
+* `alias`
+  * `advisoryId`, `scheme`, `value` with index `{scheme:1, value:1}`.
+* `affected`
+  * `advisoryId`, `platform`, `name`, `versionRange`, `cpe`, `purl`, `fixedBy`, `introducedVersion`.
+  * Index `{platform:1, name:1}`, `{advisoryId:1}`.
+* `reference`
+  * `advisoryId`, `url`, `kind`, `sourceTag` (e.g., advisory/patch/kb).
+* Flags collections: `kev_flag`, `ru_flags`, `jp_flags`, `psirt_flags` keyed by `advisoryId`.
+* `merge_event`
+  * `_id`, `advisoryKey`, `beforeHash`, `afterHash`, `mergedAt`, `inputs` (document ids).
+* `export_state`
+  * `_id` (`json`/`trivydb`), `baseExportId`, `baseDigest`, `lastFullDigest`, `lastDeltaDigest`, `exportCursor`, `targetRepo`, `exporterVersion`.
+* `locks`
+  * `_id` (`jobKey`), `holder`, `acquiredAt`, `heartbeatAt`, `leaseMs`, `ttlAt` (TTL index cleans dead locks).
+* `jobs`
+  * `_id`, `type`, `args`, `state`, `startedAt`, `endedAt`, `error`, `owner`, `heartbeatAt`, `timeoutMs`.
+
+**GridFS buckets**: `fs.documents` for raw large payloads; referenced by `document.gridFsId`.
+
+---
+
+## 4) Job & Scheduler Model
+
+* Scheduler stores cron expressions per source/exporter in config; persists next-run pointers in Mongo.
+* Jobs acquire locks (`locks` collection) to ensure singleton execution per source/exporter.
+* Supports manual triggers via API endpoints (`POST /jobs/{type}`) and pause/resume toggles per source.
+
+---
+
+## 5) Connector Contracts
+
+Connectors implement:
+
+```csharp
+public interface IFeedConnector {
+    string SourceName { get; }
+    Task FetchAsync(IServiceProvider sp, CancellationToken ct);
+    Task ParseAsync(IServiceProvider sp, CancellationToken ct);
+    Task MapAsync(IServiceProvider sp, CancellationToken ct);
+}
+```
+
+* Fetch populates `document` rows respecting rate limits, conditional GET, and `source_state.cursor`.
+* Parse validates schema (JSON Schema, XSD) and writes sanitized DTO payloads.
+* Map produces canonical advisory rows + provenance entries; must be idempotent.
+* Base helpers in `StellaOps.Feedser.Source.Common` provide HTTP clients, retry policies, and watermark utilities.
+
+---
+
+## 6) Merge & Normalization
+
+* Canonical model stored in `StellaOps.Feedser.Models` with serialization contracts used by storage/export layers.
+* `StellaOps.Feedser.Normalization` handles NEVRA/EVR/PURL range parsing, CVSS normalization, localization.
+* `StellaOps.Feedser.Merge` builds alias graphs keyed by CVE first, then falls back to vendor/regional IDs.
+* Precedence rules: PSIRT/OVAL overrides generic ranges; KEV only toggles exploitation; regional feeds enrich severity but don’t override vendor truth.
+* Determinism enforced via canonical JSON hashing logged in `merge_event`.
+
+---
+
+## 7) Exporters
+
+* JSON exporter mirrors `aquasecurity/vuln-list` layout with deterministic ordering and reproducible timestamps.
+* Trivy DB exporter initially shells out to `trivy-db` builder; later will emit BoltDB directly.
+* `StellaOps.Feedser.Storage.Mongo` provides cursors for delta exports based on `export_state.exportCursor`.
+* Export jobs produce OCI tarballs (layer media type `application/vnd.aquasec.trivy.db.layer.v1.tar+gzip`) and optionally push via ORAS.
+
+---
+
+## 8) Observability
+
+* Serilog structured logging with enrichment fields (`source`, `uri`, `stage`, `durationMs`).
+* OpenTelemetry traces around fetch/parse/map/export; metrics for rate limit hits, schema failures, dedupe ratios, package size.
+* Prometheus scraping endpoint served by WebService.
+
+---
+
+## 9) Security Considerations
+
+* Offline-first: connectors only reach allowlisted hosts.
+* BDU LLM fallback gated by config flag; logs audit trail with confidence score.
+* No secrets written to logs; secrets loaded via environment or mounted files.
+* Signing handled outside Feedser pipeline.
+
+---
+
+## 10) Deployment Notes
+
+* Default storage MongoDB; for air-gapped, bundle Mongo image + seeded data backup.
+* Horizontal scale achieved via multiple web service instances sharing Mongo locks.
+* Provide `feedser.yaml` template describing sources, rate limits, and export settings.

src/StellaOps.Feedser/StellaOps.Feedser.Core/AGENTS.md

@@ -0,0 +1,27 @@
+# AGENTS
+## Role
+Job orchestration and lifecycle. Registers job definitions, schedules execution, triggers runs, reports status for connectors and exporters.
+## Scope
+- Contracts: IJob (execute with CancellationToken), JobRunStatus, JobTriggerOutcome/Result.
+- Registration: JobSchedulerBuilder.AddJob<T>(kind, cronExpression?, timeout?, leaseDuration?); options recorded in JobSchedulerOptions.
+- Plugin host integration discovers IJob providers via registered IDependencyInjectionRoutine implementations.
+- Coordination: start/stop, single-flight via storage locks/leases, run bookkeeping (status, timings, errors).
+- Triggering: manual/cron/API; parameterized runs; idempotent rejection if already running.
+- Surfacing: enumerate definitions, last run, recent runs, active runs to WebService endpoints.
+## Participants
+- WebService exposes REST endpoints for definitions, runs, active, and trigger.
+- Storage.Mongo persists job definitions metadata, run documents, and leases (locks collection).
+- Source connectors and Exporters implement IJob and are registered into the scheduler via DI and Plugin routines.
+- Models/Merge/Export are invoked indirectly through jobs.
+- Plugin host runtime loads dependency injection routines that register job definitions.
+## Interfaces & contracts
+- Kind naming: family:source:verb (e.g., nvd:fetch, redhat:map, export:trivy-db).
+- Timeout and lease duration enforce cancellation and duplicate-prevention.
+- TimeProvider used for deterministic timing in tests.
+## In/Out of scope
+In: job lifecycle, registration, trigger semantics, run metadata.
+Out: business logic of connectors/exporters, HTTP handlers (owned by WebService).
+## Observability & security expectations
+- Metrics: job.run.started/succeeded/failed, job.durationMs, job.concurrent.rejected, job.alreadyRunning.
+- Logs: kind, trigger, params hash, lease holder, outcome; redact params containing secrets.
+- Honor CancellationToken early and often.

src/StellaOps.Feedser/StellaOps.Feedser.Core/Class1.cs

@@ -1,8 +0,0 @@
-namespace StellaOps.Feedser.Core;
-
-/// <summary>
-/// Marker type for assembly discovery.
-/// </summary>
-public sealed class FeedserCoreMarker
-{
-}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/IJob.cs

@@ -0,0 +1,6 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public interface IJob
+{
+    Task ExecuteAsync(JobExecutionContext context, CancellationToken cancellationToken);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/IJobCoordinator.cs

@@ -0,0 +1,18 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public interface IJobCoordinator
+{
+    Task<JobTriggerResult> TriggerAsync(string kind, IReadOnlyDictionary<string, object?>? parameters, string trigger, CancellationToken cancellationToken);
+
+    Task<IReadOnlyList<JobDefinition>> GetDefinitionsAsync(CancellationToken cancellationToken);
+
+    Task<IReadOnlyList<JobRunSnapshot>> GetRecentRunsAsync(string? kind, int limit, CancellationToken cancellationToken);
+
+    Task<IReadOnlyList<JobRunSnapshot>> GetActiveRunsAsync(CancellationToken cancellationToken);
+
+    Task<JobRunSnapshot?> GetRunAsync(Guid runId, CancellationToken cancellationToken);
+
+    Task<JobRunSnapshot?> GetLastRunAsync(string kind, CancellationToken cancellationToken);
+
+    Task<IReadOnlyDictionary<string, JobRunSnapshot>> GetLastRunsAsync(IEnumerable<string> kinds, CancellationToken cancellationToken);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/IJobStore.cs

@@ -0,0 +1,20 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public interface IJobStore
+{
+    Task<JobRunSnapshot> CreateAsync(JobRunCreateRequest request, CancellationToken cancellationToken);
+
+    Task<JobRunSnapshot?> TryStartAsync(Guid runId, DateTimeOffset startedAt, CancellationToken cancellationToken);
+
+    Task<JobRunSnapshot?> TryCompleteAsync(Guid runId, JobRunCompletion completion, CancellationToken cancellationToken);
+
+    Task<JobRunSnapshot?> FindAsync(Guid runId, CancellationToken cancellationToken);
+
+    Task<IReadOnlyList<JobRunSnapshot>> GetRecentRunsAsync(string? kind, int limit, CancellationToken cancellationToken);
+
+    Task<IReadOnlyList<JobRunSnapshot>> GetActiveRunsAsync(CancellationToken cancellationToken);
+
+    Task<JobRunSnapshot?> GetLastRunAsync(string kind, CancellationToken cancellationToken);
+
+    Task<IReadOnlyDictionary<string, JobRunSnapshot>> GetLastRunsAsync(IEnumerable<string> kinds, CancellationToken cancellationToken);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/ILeaseStore.cs

@@ -0,0 +1,10 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public interface ILeaseStore
+{
+    Task<JobLease?> TryAcquireAsync(string key, string holder, TimeSpan leaseDuration, DateTimeOffset now, CancellationToken cancellationToken);
+
+    Task<JobLease?> HeartbeatAsync(string key, string holder, TimeSpan leaseDuration, DateTimeOffset now, CancellationToken cancellationToken);
+
+    Task<bool> ReleaseAsync(string key, string holder, CancellationToken cancellationToken);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobCoordinator.cs

@@ -0,0 +1,635 @@
+using System.Collections;
+using System.Diagnostics;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using System.Globalization;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed class JobCoordinator : IJobCoordinator
+{
+    private readonly JobSchedulerOptions _options;
+    private readonly IJobStore _jobStore;
+    private readonly ILeaseStore _leaseStore;
+    private readonly IServiceScopeFactory _scopeFactory;
+    private readonly ILogger<JobCoordinator> _logger;
+    private readonly ILoggerFactory _loggerFactory;
+    private readonly TimeProvider _timeProvider;
+    private readonly JobDiagnostics _diagnostics;
+    private readonly string _holderId;
+
+    public JobCoordinator(
+        IOptions<JobSchedulerOptions> optionsAccessor,
+        IJobStore jobStore,
+        ILeaseStore leaseStore,
+        IServiceScopeFactory scopeFactory,
+        ILogger<JobCoordinator> logger,
+        ILoggerFactory loggerFactory,
+        TimeProvider timeProvider,
+        JobDiagnostics diagnostics)
+    {
+        _options = (optionsAccessor ?? throw new ArgumentNullException(nameof(optionsAccessor))).Value;
+        _jobStore = jobStore ?? throw new ArgumentNullException(nameof(jobStore));
+        _leaseStore = leaseStore ?? throw new ArgumentNullException(nameof(leaseStore));
+        _scopeFactory = scopeFactory ?? throw new ArgumentNullException(nameof(scopeFactory));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        _loggerFactory = loggerFactory ?? throw new ArgumentNullException(nameof(loggerFactory));
+        _timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
+        _diagnostics = diagnostics ?? throw new ArgumentNullException(nameof(diagnostics));
+        _holderId = BuildHolderId();
+    }
+
+    public async Task<JobTriggerResult> TriggerAsync(string kind, IReadOnlyDictionary<string, object?>? parameters, string trigger, CancellationToken cancellationToken)
+    {
+        using var triggerActivity = _diagnostics.StartTriggerActivity(kind, trigger);
+
+        if (!_options.Definitions.TryGetValue(kind, out var definition))
+        {
+            var result = JobTriggerResult.NotFound($"Job kind '{kind}' is not registered.");
+            triggerActivity?.SetStatus(ActivityStatusCode.Error, result.ErrorMessage);
+            triggerActivity?.SetTag("job.trigger.outcome", result.Outcome.ToString());
+            _diagnostics.RecordTriggerRejected(kind, trigger, "not_found");
+            return result;
+        }
+
+        triggerActivity?.SetTag("job.enabled", definition.Enabled);
+        triggerActivity?.SetTag("job.timeout_seconds", definition.Timeout.TotalSeconds);
+        triggerActivity?.SetTag("job.lease_seconds", definition.LeaseDuration.TotalSeconds);
+
+        if (!definition.Enabled)
+        {
+            var result = JobTriggerResult.Disabled($"Job kind '{kind}' is disabled.");
+            triggerActivity?.SetStatus(ActivityStatusCode.Ok, "disabled");
+            triggerActivity?.SetTag("job.trigger.outcome", result.Outcome.ToString());
+            _diagnostics.RecordTriggerRejected(kind, trigger, "disabled");
+            return result;
+        }
+
+        parameters ??= new Dictionary<string, object?>();
+
+        var parameterSnapshot = parameters.Count == 0
+            ? new Dictionary<string, object?>(StringComparer.Ordinal)
+            : new Dictionary<string, object?>(parameters, StringComparer.Ordinal);
+
+        if (!TryNormalizeParameters(parameterSnapshot, out var normalizedParameters, out var parameterError))
+        {
+            var message = string.IsNullOrWhiteSpace(parameterError)
+                ? "Job trigger parameters contain unsupported values."
+                : parameterError;
+            triggerActivity?.SetStatus(ActivityStatusCode.Error, message);
+            triggerActivity?.SetTag("job.trigger.outcome", JobTriggerOutcome.InvalidParameters.ToString());
+            _diagnostics.RecordTriggerRejected(kind, trigger, "invalid_parameters");
+            return JobTriggerResult.InvalidParameters(message);
+        }
+
+        parameterSnapshot = normalizedParameters;
+
+        string? parametersHash;
+        try
+        {
+            parametersHash = JobParametersHasher.Compute(parameterSnapshot);
+        }
+        catch (Exception ex)
+        {
+            var message = $"Job trigger parameters cannot be serialized: {ex.Message}";
+            triggerActivity?.SetStatus(ActivityStatusCode.Error, message);
+            triggerActivity?.SetTag("job.trigger.outcome", JobTriggerOutcome.InvalidParameters.ToString());
+            _diagnostics.RecordTriggerRejected(kind, trigger, "invalid_parameters");
+            _logger.LogWarning(ex, "Failed to serialize parameters for job {Kind}", kind);
+            return JobTriggerResult.InvalidParameters(message);
+        }
+
+        triggerActivity?.SetTag("job.parameters_count", parameterSnapshot.Count);
+
+        var now = _timeProvider.GetUtcNow();
+        var leaseDuration = definition.LeaseDuration <= TimeSpan.Zero ? _options.DefaultLeaseDuration : definition.LeaseDuration;
+
+        JobLease? lease = null;
+        try
+        {
+            lease = await _leaseStore.TryAcquireAsync(definition.LeaseKey, _holderId, leaseDuration, now, cancellationToken).ConfigureAwait(false);
+            if (lease is null)
+            {
+                var result = JobTriggerResult.AlreadyRunning($"Job '{kind}' is already running.");
+                triggerActivity?.SetStatus(ActivityStatusCode.Ok, "already_running");
+                triggerActivity?.SetTag("job.trigger.outcome", result.Outcome.ToString());
+                _diagnostics.RecordTriggerRejected(kind, trigger, "already_running");
+                return result;
+            }
+
+            var createdAt = _timeProvider.GetUtcNow();
+            var request = new JobRunCreateRequest(
+                definition.Kind,
+                trigger,
+                parameterSnapshot,
+                parametersHash,
+                definition.Timeout,
+                leaseDuration,
+                createdAt);
+
+            triggerActivity?.SetTag("job.parameters_hash", request.ParametersHash);
+
+            var run = await _jobStore.CreateAsync(request, cancellationToken).ConfigureAwait(false);
+            var startedAt = _timeProvider.GetUtcNow();
+            var started = await _jobStore.TryStartAsync(run.RunId, startedAt, cancellationToken).ConfigureAwait(false) ?? run;
+
+            triggerActivity?.SetTag("job.run_id", started.RunId);
+            triggerActivity?.SetTag("job.created_at", createdAt.UtcDateTime);
+            triggerActivity?.SetTag("job.started_at", started.StartedAt?.UtcDateTime ?? startedAt.UtcDateTime);
+
+            var linkedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+            if (definition.Timeout > TimeSpan.Zero)
+            {
+                linkedTokenSource.CancelAfter(definition.Timeout);
+            }
+
+            var capturedLease = lease ?? throw new InvalidOperationException("Lease acquisition returned null.");
+            try
+            {
+                _ = Task.Run(() => ExecuteJobAsync(definition, capturedLease, started, parameterSnapshot, trigger, linkedTokenSource), CancellationToken.None)
+                    .ContinueWith(t =>
+                    {
+                        if (t.Exception is not null)
+                        {
+                            _logger.LogError(t.Exception, "Unhandled job execution failure for {Kind}", definition.Kind);
+                        }
+                    },
+                    TaskContinuationOptions.OnlyOnFaulted | TaskContinuationOptions.ExecuteSynchronously);
+                lease = null; // released by background job execution
+            }
+            catch (Exception ex)
+            {
+                lease = capturedLease; // ensure outer finally releases if scheduling fails
+                triggerActivity?.SetStatus(ActivityStatusCode.Error, ex.Message);
+                triggerActivity?.SetTag("job.trigger.outcome", "exception");
+                _diagnostics.RecordTriggerRejected(kind, trigger, "queue_failure");
+                throw;
+            }
+
+            var accepted = JobTriggerResult.Accepted(started);
+            _diagnostics.RecordTriggerAccepted(kind, trigger);
+            triggerActivity?.SetStatus(ActivityStatusCode.Ok);
+            triggerActivity?.SetTag("job.trigger.outcome", accepted.Outcome.ToString());
+            return accepted;
+        }
+        catch (Exception ex)
+        {
+            triggerActivity?.SetStatus(ActivityStatusCode.Error, ex.Message);
+            triggerActivity?.SetTag("job.trigger.outcome", "exception");
+            _diagnostics.RecordTriggerRejected(kind, trigger, "exception");
+            throw;
+        }
+        finally
+        {
+            // Release handled by background execution path. If we failed before scheduling, release here.
+            if (lease is not null)
+            {
+                var releaseError = await TryReleaseLeaseAsync(lease, definition.Kind).ConfigureAwait(false);
+                if (releaseError is not null)
+                {
+                    _logger.LogError(releaseError, "Failed to release lease {LeaseKey} for job {Kind}", lease.Key, definition.Kind);
+                }
+            }
+        }
+    }
+
+    public Task<IReadOnlyList<JobDefinition>> GetDefinitionsAsync(CancellationToken cancellationToken)
+    {
+        IReadOnlyList<JobDefinition> results = _options.Definitions.Values.OrderBy(x => x.Kind, StringComparer.Ordinal).ToArray();
+        return Task.FromResult(results);
+    }
+
+    public Task<IReadOnlyList<JobRunSnapshot>> GetRecentRunsAsync(string? kind, int limit, CancellationToken cancellationToken)
+        => _jobStore.GetRecentRunsAsync(kind, limit, cancellationToken);
+
+    public Task<IReadOnlyList<JobRunSnapshot>> GetActiveRunsAsync(CancellationToken cancellationToken)
+        => _jobStore.GetActiveRunsAsync(cancellationToken);
+
+    public Task<JobRunSnapshot?> GetRunAsync(Guid runId, CancellationToken cancellationToken)
+        => _jobStore.FindAsync(runId, cancellationToken);
+
+    public Task<JobRunSnapshot?> GetLastRunAsync(string kind, CancellationToken cancellationToken)
+        => _jobStore.GetLastRunAsync(kind, cancellationToken);
+
+    public Task<IReadOnlyDictionary<string, JobRunSnapshot>> GetLastRunsAsync(IEnumerable<string> kinds, CancellationToken cancellationToken)
+        => _jobStore.GetLastRunsAsync(kinds, cancellationToken);
+
+    private static bool TryNormalizeParameters(
+        IReadOnlyDictionary<string, object?> source,
+        out Dictionary<string, object?> normalized,
+        out string? error)
+    {
+        if (source.Count == 0)
+        {
+            normalized = new Dictionary<string, object?>(StringComparer.Ordinal);
+            error = null;
+            return true;
+        }
+
+        normalized = new Dictionary<string, object?>(source.Count, StringComparer.Ordinal);
+        foreach (var kvp in source)
+        {
+            if (string.IsNullOrWhiteSpace(kvp.Key))
+            {
+                error = "Parameter keys must be non-empty strings.";
+                normalized = default!;
+                return false;
+            }
+
+            try
+            {
+                normalized[kvp.Key] = NormalizeParameterValue(kvp.Value);
+            }
+            catch (Exception ex)
+            {
+                error = $"Parameter '{kvp.Key}' cannot be serialized: {ex.Message}";
+                normalized = default!;
+                return false;
+            }
+        }
+
+        error = null;
+        return true;
+    }
+
+    private static object? NormalizeParameterValue(object? value)
+    {
+        if (value is null)
+        {
+            return null;
+        }
+
+        switch (value)
+        {
+            case string or bool or double or decimal:
+                return value;
+            case byte or sbyte or short or ushort or int or long:
+                return Convert.ToInt64(value, CultureInfo.InvariantCulture);
+            case uint ui:
+                return Convert.ToInt64(ui);
+            case ulong ul when ul <= long.MaxValue:
+                return (long)ul;
+            case ulong ul:
+                return ul.ToString(CultureInfo.InvariantCulture);
+            case float f:
+                return (double)f;
+            case DateTime dt:
+                return dt.Kind == DateTimeKind.Utc ? dt : dt.ToUniversalTime();
+            case DateTimeOffset dto:
+                return dto.ToUniversalTime();
+            case TimeSpan ts:
+                return ts.ToString("c", CultureInfo.InvariantCulture);
+            case Guid guid:
+                return guid.ToString("D");
+            case Enum enumValue:
+                return enumValue.ToString();
+            case byte[] bytes:
+                return Convert.ToBase64String(bytes);
+            case JsonDocument document:
+                return NormalizeJsonElement(document.RootElement);
+            case JsonElement element:
+                return NormalizeJsonElement(element);
+            case IDictionary dictionary:
+            {
+                var nested = new SortedDictionary<string, object?>(StringComparer.Ordinal);
+                foreach (DictionaryEntry entry in dictionary)
+                {
+                    if (entry.Key is not string key || string.IsNullOrWhiteSpace(key))
+                    {
+                        throw new InvalidOperationException("Nested dictionary keys must be non-empty strings.");
+                    }
+
+                    nested[key] = NormalizeParameterValue(entry.Value);
+                }
+
+                return nested;
+            }
+            case IEnumerable enumerable when value is not string:
+            {
+                var list = new List<object?>();
+                foreach (var item in enumerable)
+                {
+                    list.Add(NormalizeParameterValue(item));
+                }
+
+                return list;
+            }
+            default:
+                throw new InvalidOperationException($"Unsupported parameter value of type '{value.GetType().FullName}'.");
+        }
+    }
+
+    private static object? NormalizeJsonElement(JsonElement element)
+    {
+        return element.ValueKind switch
+        {
+            JsonValueKind.Null => null,
+            JsonValueKind.String => element.GetString(),
+            JsonValueKind.True => true,
+            JsonValueKind.False => false,
+            JsonValueKind.Number => element.TryGetInt64(out var l)
+                ? l
+                : element.TryGetDecimal(out var dec)
+                    ? dec
+                    : element.GetDouble(),
+            JsonValueKind.Object => NormalizeJsonObject(element),
+            JsonValueKind.Array => NormalizeJsonArray(element),
+            _ => throw new InvalidOperationException($"Unsupported JSON value '{element.ValueKind}'."),
+        };
+    }
+
+    private static SortedDictionary<string, object?> NormalizeJsonObject(JsonElement element)
+    {
+        var result = new SortedDictionary<string, object?>(StringComparer.Ordinal);
+        foreach (var property in element.EnumerateObject())
+        {
+            result[property.Name] = NormalizeJsonElement(property.Value);
+        }
+
+        return result;
+    }
+
+    private static List<object?> NormalizeJsonArray(JsonElement element)
+    {
+        var items = new List<object?>();
+        foreach (var item in element.EnumerateArray())
+        {
+            items.Add(NormalizeJsonElement(item));
+        }
+
+        return items;
+    }
+
+    private async Task<JobRunSnapshot?> CompleteRunAsync(Guid runId, JobRunStatus status, string? error, CancellationToken cancellationToken)
+    {
+        var completedAt = _timeProvider.GetUtcNow();
+        var completion = new JobRunCompletion(status, completedAt, error);
+        return await _jobStore.TryCompleteAsync(runId, completion, cancellationToken).ConfigureAwait(false);
+    }
+
+    private TimeSpan? ResolveDuration(JobRunSnapshot original, JobRunSnapshot? completed)
+    {
+        if (completed?.Duration is { } duration)
+        {
+            return duration;
+        }
+
+        var startedAt = completed?.StartedAt ?? original.StartedAt ?? original.CreatedAt;
+        var completedAt = completed?.CompletedAt ?? _timeProvider.GetUtcNow();
+        var elapsed = completedAt - startedAt;
+        return elapsed >= TimeSpan.Zero ? elapsed : null;
+    }
+
+    private static async Task<Exception?> ObserveLeaseTaskAsync(Task heartbeatTask)
+    {
+        try
+        {
+            await heartbeatTask.ConfigureAwait(false);
+            return null;
+        }
+        catch (OperationCanceledException)
+        {
+            return null;
+        }
+        catch (Exception ex)
+        {
+            return ex;
+        }
+    }
+
+    private async Task<Exception?> TryReleaseLeaseAsync(JobLease lease, string kind)
+    {
+        try
+        {
+            await _leaseStore.ReleaseAsync(lease.Key, _holderId, CancellationToken.None).ConfigureAwait(false);
+            return null;
+        }
+        catch (Exception ex)
+        {
+            return new LeaseMaintenanceException($"Failed to release lease for job '{kind}'.", ex);
+        }
+    }
+
+    private static Exception? CombineLeaseExceptions(Exception? first, Exception? second)
+    {
+        if (first is null)
+        {
+            return second;
+        }
+
+        if (second is null)
+        {
+            return first;
+        }
+
+        return new AggregateException(first, second);
+    }
+
+    private async Task ExecuteJobAsync(
+        JobDefinition definition,
+        JobLease lease,
+        JobRunSnapshot run,
+        IReadOnlyDictionary<string, object?> parameters,
+        string trigger,
+        CancellationTokenSource linkedTokenSource)
+    {
+        using (linkedTokenSource)
+        {
+            var cancellationToken = linkedTokenSource.Token;
+            using var heartbeatCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+            var heartbeatTask = MaintainLeaseAsync(definition, lease, heartbeatCts.Token);
+
+            using var activity = _diagnostics.StartExecutionActivity(run.Kind, trigger, run.RunId);
+            activity?.SetTag("job.timeout_seconds", definition.Timeout.TotalSeconds);
+            activity?.SetTag("job.lease_seconds", definition.LeaseDuration.TotalSeconds);
+            activity?.SetTag("job.parameters_count", parameters.Count);
+            activity?.SetTag("job.created_at", run.CreatedAt.UtcDateTime);
+            activity?.SetTag("job.started_at", (run.StartedAt ?? run.CreatedAt).UtcDateTime);
+            activity?.SetTag("job.parameters_hash", run.ParametersHash);
+
+            _diagnostics.RecordRunStarted(run.Kind);
+
+            JobRunStatus finalStatus = JobRunStatus.Succeeded;
+            string? error = null;
+            Exception? executionException = null;
+            JobRunSnapshot? completedSnapshot = null;
+            Exception? leaseException = null;
+
+            try
+            {
+                using var scope = _scopeFactory.CreateScope();
+                var job = (IJob)scope.ServiceProvider.GetRequiredService(definition.JobType);
+                var jobLogger = _loggerFactory.CreateLogger(definition.JobType);
+
+                var context = new JobExecutionContext(
+                    run.RunId,
+                    run.Kind,
+                    trigger,
+                    parameters,
+                    scope.ServiceProvider,
+                    _timeProvider,
+                    jobLogger);
+
+                await job.ExecuteAsync(context, cancellationToken).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException oce)
+            {
+                finalStatus = JobRunStatus.Cancelled;
+                error = oce.Message;
+                executionException = oce;
+            }
+            catch (Exception ex)
+            {
+                finalStatus = JobRunStatus.Failed;
+                error = ex.ToString();
+                executionException = ex;
+            }
+            finally
+            {
+                heartbeatCts.Cancel();
+
+                leaseException = await ObserveLeaseTaskAsync(heartbeatTask).ConfigureAwait(false);
+
+                var releaseException = await TryReleaseLeaseAsync(lease, definition.Kind).ConfigureAwait(false);
+                leaseException = CombineLeaseExceptions(leaseException, releaseException);
+
+                if (leaseException is not null)
+                {
+                    var leaseMessage = $"Lease maintenance failed: {leaseException.GetType().Name}: {leaseException.Message}";
+                    if (finalStatus != JobRunStatus.Failed)
+                    {
+                        finalStatus = JobRunStatus.Failed;
+                        error = leaseMessage;
+                        executionException = leaseException;
+                    }
+                    else
+                    {
+                        error = string.IsNullOrWhiteSpace(error)
+                            ? leaseMessage
+                            : $"{error}{Environment.NewLine}{leaseMessage}";
+                        executionException = executionException is null
+                            ? leaseException
+                            : new AggregateException(executionException, leaseException);
+                    }
+                }
+            }
+
+            completedSnapshot = await CompleteRunAsync(run.RunId, finalStatus, error, CancellationToken.None).ConfigureAwait(false);
+
+            if (!string.IsNullOrWhiteSpace(error))
+            {
+                activity?.SetTag("job.error", error);
+            }
+
+            activity?.SetTag("job.status", finalStatus.ToString());
+
+            var completedDuration = ResolveDuration(run, completedSnapshot);
+            if (completedDuration.HasValue)
+            {
+                activity?.SetTag("job.duration_seconds", completedDuration.Value.TotalSeconds);
+            }
+
+            switch (finalStatus)
+            {
+                case JobRunStatus.Succeeded:
+                    activity?.SetStatus(ActivityStatusCode.Ok);
+                    _logger.LogInformation("Job {Kind} run {RunId} succeeded", run.Kind, run.RunId);
+                    break;
+                case JobRunStatus.Cancelled:
+                    activity?.SetStatus(ActivityStatusCode.Ok, "cancelled");
+                    _logger.LogWarning(executionException, "Job {Kind} run {RunId} cancelled", run.Kind, run.RunId);
+                    break;
+                case JobRunStatus.Failed:
+                    activity?.SetStatus(ActivityStatusCode.Error, executionException?.Message ?? error);
+                    _logger.LogError(executionException, "Job {Kind} run {RunId} failed", run.Kind, run.RunId);
+                    break;
+            }
+
+            _diagnostics.RecordRunCompleted(run.Kind, finalStatus, completedDuration, error);
+        }
+    }
+
+    private async Task MaintainLeaseAsync(JobDefinition definition, JobLease lease, CancellationToken cancellationToken)
+    {
+        var leaseDuration = lease.LeaseDuration <= TimeSpan.Zero ? _options.DefaultLeaseDuration : lease.LeaseDuration;
+        var delay = TimeSpan.FromMilliseconds(Math.Max(1000, leaseDuration.TotalMilliseconds / 2));
+
+        while (!cancellationToken.IsCancellationRequested)
+        {
+            try
+            {
+                await Task.Delay(delay, cancellationToken).ConfigureAwait(false);
+            }
+            catch (TaskCanceledException)
+            {
+                break;
+            }
+
+            var now = _timeProvider.GetUtcNow();
+            try
+            {
+                await _leaseStore.HeartbeatAsync(definition.LeaseKey, _holderId, leaseDuration, now, cancellationToken).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                throw new LeaseMaintenanceException($"Failed to heartbeat lease for job '{definition.Kind}'.", ex);
+            }
+        }
+    }
+
+    private static string BuildHolderId()
+    {
+        var machine = Environment.MachineName;
+        var processId = Environment.ProcessId;
+        return $"{machine}:{processId}";
+    }
+}
+
+internal sealed class LeaseMaintenanceException : Exception
+{
+    public LeaseMaintenanceException(string message, Exception innerException)
+        : base(message, innerException)
+    {
+    }
+}
+
+internal static class JobParametersHasher
+{
+    internal static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        WriteIndented = false,
+    };
+
+    public static string? Compute(IReadOnlyDictionary<string, object?> parameters)
+    {
+        if (parameters is null || parameters.Count == 0)
+        {
+            return null;
+        }
+
+        var canonicalJson = JsonSerializer.Serialize(Sort(parameters), SerializerOptions);
+        var bytes = Encoding.UTF8.GetBytes(canonicalJson);
+        var hash = SHA256.HashData(bytes);
+        return Convert.ToHexString(hash).ToLowerInvariant();
+    }
+
+    private static SortedDictionary<string, object?> Sort(IReadOnlyDictionary<string, object?> parameters)
+    {
+        var sorted = new SortedDictionary<string, object?>(StringComparer.Ordinal);
+        foreach (var kvp in parameters)
+        {
+            sorted[kvp.Key] = kvp.Value;
+        }
+
+        return sorted;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobDefinition.cs

@@ -0,0 +1,12 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed record JobDefinition(
+    string Kind,
+    Type JobType,
+    TimeSpan Timeout,
+    TimeSpan LeaseDuration,
+    string? CronExpression,
+    bool Enabled)
+{
+    public string LeaseKey => $"job:{Kind}";
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobDiagnostics.cs

@@ -0,0 +1,171 @@
+using System.Diagnostics;
+using System.Diagnostics.Metrics;
+
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed class JobDiagnostics : IDisposable
+{
+    public const string ActivitySourceName = "StellaOps.Feedser.Jobs";
+    public const string MeterName = "StellaOps.Feedser.Jobs";
+    public const string TriggerActivityName = "feedser.job.trigger";
+    public const string ExecuteActivityName = "feedser.job.execute";
+    public const string SchedulerActivityName = "feedser.scheduler.evaluate";
+
+    private readonly Counter<long> _triggersAccepted;
+    private readonly Counter<long> _triggersRejected;
+    private readonly Counter<long> _runsCompleted;
+    private readonly UpDownCounter<long> _runsActive;
+    private readonly Histogram<double> _runDurationSeconds;
+    private readonly Histogram<double> _schedulerSkewMilliseconds;
+
+    public JobDiagnostics()
+    {
+        ActivitySource = new ActivitySource(ActivitySourceName);
+        Meter = new Meter(MeterName);
+
+        _triggersAccepted = Meter.CreateCounter<long>(
+            name: "feedser.jobs.triggers.accepted",
+            unit: "count",
+            description: "Number of job trigger requests accepted for execution.");
+
+        _triggersRejected = Meter.CreateCounter<long>(
+            name: "feedser.jobs.triggers.rejected",
+            unit: "count",
+            description: "Number of job trigger requests rejected or ignored by the coordinator.");
+
+        _runsCompleted = Meter.CreateCounter<long>(
+            name: "feedser.jobs.runs.completed",
+            unit: "count",
+            description: "Number of job executions that have finished grouped by outcome.");
+
+        _runsActive = Meter.CreateUpDownCounter<long>(
+            name: "feedser.jobs.runs.active",
+            unit: "count",
+            description: "Current number of running job executions.");
+
+        _runDurationSeconds = Meter.CreateHistogram<double>(
+            name: "feedser.jobs.runs.duration",
+            unit: "s",
+            description: "Distribution of job execution durations in seconds.");
+
+        _schedulerSkewMilliseconds = Meter.CreateHistogram<double>(
+            name: "feedser.scheduler.skew",
+            unit: "ms",
+            description: "Difference between the intended and actual scheduler fire time in milliseconds.");
+    }
+
+    public ActivitySource ActivitySource { get; }
+
+    public Meter Meter { get; }
+
+    public Activity? StartTriggerActivity(string kind, string trigger)
+    {
+        var activity = ActivitySource.StartActivity(TriggerActivityName, ActivityKind.Internal);
+        if (activity is not null)
+        {
+            activity.SetTag("job.kind", kind);
+            activity.SetTag("job.trigger", trigger);
+        }
+
+        return activity;
+    }
+
+    public Activity? StartSchedulerActivity(string kind, DateTimeOffset scheduledFor, DateTimeOffset invokedAt)
+    {
+        var activity = ActivitySource.StartActivity(SchedulerActivityName, ActivityKind.Internal);
+        if (activity is not null)
+        {
+            activity.SetTag("job.kind", kind);
+            activity.SetTag("job.scheduled_for", scheduledFor.UtcDateTime);
+            activity.SetTag("job.invoked_at", invokedAt.UtcDateTime);
+            activity.SetTag("job.scheduler_delay_ms", (invokedAt - scheduledFor).TotalMilliseconds);
+        }
+
+        return activity;
+    }
+
+    public Activity? StartExecutionActivity(string kind, string trigger, Guid runId)
+    {
+        var activity = ActivitySource.StartActivity(ExecuteActivityName, ActivityKind.Internal);
+        if (activity is not null)
+        {
+            activity.SetTag("job.kind", kind);
+            activity.SetTag("job.trigger", trigger);
+            activity.SetTag("job.run_id", runId);
+        }
+
+        return activity;
+    }
+
+    public void RecordTriggerAccepted(string kind, string trigger)
+    {
+        var tags = new TagList
+        {
+            { "job.kind", kind },
+            { "job.trigger", trigger },
+        };
+        _triggersAccepted.Add(1, tags);
+    }
+
+    public void RecordTriggerRejected(string kind, string trigger, string reason)
+    {
+        var tags = new TagList
+        {
+            { "job.kind", kind },
+            { "job.trigger", trigger },
+            { "job.reason", reason },
+        };
+        _triggersRejected.Add(1, tags);
+    }
+
+    public void RecordRunStarted(string kind)
+    {
+        var tags = new TagList { { "job.kind", kind } };
+        _runsActive.Add(1, tags);
+    }
+
+    public void RecordRunCompleted(string kind, JobRunStatus status, TimeSpan? duration, string? error)
+    {
+        var outcome = status.ToString();
+
+        var completionTags = new TagList
+        {
+            { "job.kind", kind },
+            { "job.status", outcome },
+        };
+
+        if (!string.IsNullOrWhiteSpace(error))
+        {
+            completionTags.Add("job.error", error);
+        }
+
+        _runsCompleted.Add(1, completionTags);
+
+        var activeTags = new TagList { { "job.kind", kind } };
+        _runsActive.Add(-1, activeTags);
+
+        if (duration.HasValue)
+        {
+            var seconds = Math.Max(duration.Value.TotalSeconds, 0d);
+            var durationTags = new TagList
+            {
+                { "job.kind", kind },
+                { "job.status", outcome },
+            };
+            _runDurationSeconds.Record(seconds, durationTags);
+        }
+    }
+
+    public void RecordSchedulerSkew(string kind, DateTimeOffset scheduledFor, DateTimeOffset invokedAt)
+    {
+        var skew = (invokedAt - scheduledFor).TotalMilliseconds;
+        var tags = new TagList { { "job.kind", kind } };
+        _schedulerSkewMilliseconds.Record(skew, tags);
+    }
+
+    public void Dispose()
+    {
+        ActivitySource.Dispose();
+        Meter.Dispose();
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobExecutionContext.cs

@@ -0,0 +1,42 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed class JobExecutionContext
+{
+    public JobExecutionContext(
+        Guid runId,
+        string kind,
+        string trigger,
+        IReadOnlyDictionary<string, object?> parameters,
+        IServiceProvider services,
+        TimeProvider timeProvider,
+        ILogger logger)
+    {
+        RunId = runId;
+        Kind = kind;
+        Trigger = trigger;
+        Parameters = parameters ?? throw new ArgumentNullException(nameof(parameters));
+        Services = services ?? throw new ArgumentNullException(nameof(services));
+        TimeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
+        Logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public Guid RunId { get; }
+
+    public string Kind { get; }
+
+    public string Trigger { get; }
+
+    public IReadOnlyDictionary<string, object?> Parameters { get; }
+
+    public IServiceProvider Services { get; }
+
+    public TimeProvider TimeProvider { get; }
+
+    public ILogger Logger { get; }
+
+    public T GetRequiredService<T>() where T : notnull
+        => Services.GetRequiredService<T>();
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobLease.cs

@@ -0,0 +1,9 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed record JobLease(
+    string Key,
+    string Holder,
+    DateTimeOffset AcquiredAt,
+    DateTimeOffset HeartbeatAt,
+    TimeSpan LeaseDuration,
+    DateTimeOffset TtlAt);

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobRunCompletion.cs

@@ -0,0 +1,6 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed record JobRunCompletion(
+    JobRunStatus Status,
+    DateTimeOffset CompletedAt,
+    string? Error);

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobRunCreateRequest.cs

@@ -0,0 +1,10 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed record JobRunCreateRequest(
+    string Kind,
+    string Trigger,
+    IReadOnlyDictionary<string, object?> Parameters,
+    string? ParametersHash,
+    TimeSpan? Timeout,
+    TimeSpan? LeaseDuration,
+    DateTimeOffset CreatedAt);

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobRunSnapshot.cs

@@ -0,0 +1,21 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+/// <summary>
+/// Immutable projection of a job run as stored in persistence.
+/// </summary>
+public sealed record JobRunSnapshot(
+    Guid RunId,
+    string Kind,
+    JobRunStatus Status,
+    DateTimeOffset CreatedAt,
+    DateTimeOffset? StartedAt,
+    DateTimeOffset? CompletedAt,
+    string Trigger,
+    string? ParametersHash,
+    string? Error,
+    TimeSpan? Timeout,
+    TimeSpan? LeaseDuration,
+    IReadOnlyDictionary<string, object?> Parameters)
+{
+    public TimeSpan? Duration => StartedAt is null || CompletedAt is null ? null : CompletedAt - StartedAt;
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobRunStatus.cs

@@ -0,0 +1,10 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public enum JobRunStatus
+{
+    Pending,
+    Running,
+    Succeeded,
+    Failed,
+    Cancelled,
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobSchedulerBuilder.cs

@@ -0,0 +1,47 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed class JobSchedulerBuilder
+{
+    private readonly IServiceCollection _services;
+
+    public JobSchedulerBuilder(IServiceCollection services)
+    {
+        _services = services ?? throw new ArgumentNullException(nameof(services));
+    }
+
+    public JobSchedulerBuilder AddJob<TJob>(
+        string kind,
+        string? cronExpression = null,
+        TimeSpan? timeout = null,
+        TimeSpan? leaseDuration = null,
+        bool enabled = true)
+        where TJob : class, IJob
+    {
+        ArgumentException.ThrowIfNullOrEmpty(kind);
+
+        _services.AddTransient<TJob>();
+        _services.Configure<JobSchedulerOptions>(options =>
+        {
+            if (options.Definitions.ContainsKey(kind))
+            {
+                throw new InvalidOperationException($"Job '{kind}' is already registered.");
+            }
+
+            var resolvedTimeout = timeout ?? options.DefaultTimeout;
+            var resolvedLease = leaseDuration ?? options.DefaultLeaseDuration;
+
+            options.Definitions.Add(kind, new JobDefinition(
+                kind,
+                typeof(TJob),
+                resolvedTimeout,
+                resolvedLease,
+                cronExpression,
+                enabled));
+        });
+
+        return this;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobSchedulerHostedService.cs

@@ -0,0 +1,165 @@
+using Cronos;
+using System.Diagnostics;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace StellaOps.Feedser.Core.Jobs;
+
+/// <summary>
+/// Background service that evaluates cron expressions for registered jobs and triggers them.
+/// </summary>
+public sealed class JobSchedulerHostedService : BackgroundService
+{
+    private readonly IJobCoordinator _coordinator;
+    private readonly JobSchedulerOptions _options;
+    private readonly ILogger<JobSchedulerHostedService> _logger;
+    private readonly TimeProvider _timeProvider;
+    private readonly JobDiagnostics _diagnostics;
+    private readonly Dictionary<string, CronExpression> _cronExpressions = new(StringComparer.Ordinal);
+    private readonly Dictionary<string, DateTimeOffset> _nextOccurrences = new(StringComparer.Ordinal);
+
+    public JobSchedulerHostedService(
+        IJobCoordinator coordinator,
+        IOptions<JobSchedulerOptions> optionsAccessor,
+        ILogger<JobSchedulerHostedService> logger,
+        TimeProvider timeProvider,
+        JobDiagnostics diagnostics)
+    {
+        _coordinator = coordinator ?? throw new ArgumentNullException(nameof(coordinator));
+        _options = (optionsAccessor ?? throw new ArgumentNullException(nameof(optionsAccessor))).Value;
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        _timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
+        _diagnostics = diagnostics ?? throw new ArgumentNullException(nameof(diagnostics));
+
+        foreach (var definition in _options.Definitions.Values)
+        {
+            if (string.IsNullOrWhiteSpace(definition.CronExpression))
+            {
+                continue;
+            }
+
+            try
+            {
+                var cron = CronExpression.Parse(definition.CronExpression!, CronFormat.Standard);
+                _cronExpressions[definition.Kind] = cron;
+            }
+            catch (CronFormatException ex)
+            {
+                _logger.LogError(ex, "Invalid cron expression '{Cron}' for job {Kind}", definition.CronExpression, definition.Kind);
+            }
+        }
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (_cronExpressions.Count == 0)
+        {
+            _logger.LogInformation("No cron-based jobs registered; scheduler idle.");
+            await Task.Delay(Timeout.Infinite, stoppingToken).ConfigureAwait(false);
+            return;
+        }
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            var now = _timeProvider.GetUtcNow();
+            var nextWake = now.AddMinutes(5); // default sleep when nothing scheduled
+
+            foreach (var (kind, cron) in _cronExpressions)
+            {
+                if (!_options.Definitions.TryGetValue(kind, out var definition) || !definition.Enabled)
+                {
+                    continue;
+                }
+
+                var next = GetNextOccurrence(kind, cron, now);
+                if (next <= now.AddMilliseconds(500))
+                {
+                    _ = TriggerJobAsync(kind, next, stoppingToken);
+                    _nextOccurrences[kind] = GetNextOccurrence(kind, cron, now.AddSeconds(1));
+                    next = _nextOccurrences[kind];
+                }
+
+                if (next < nextWake)
+                {
+                    nextWake = next;
+                }
+            }
+
+            var delay = nextWake - now;
+            if (delay < TimeSpan.FromSeconds(1))
+            {
+                delay = TimeSpan.FromSeconds(1);
+            }
+
+            try
+            {
+                await Task.Delay(delay, stoppingToken).ConfigureAwait(false);
+            }
+            catch (TaskCanceledException)
+            {
+                break;
+            }
+        }
+    }
+
+    private DateTimeOffset GetNextOccurrence(string kind, CronExpression cron, DateTimeOffset reference)
+    {
+        if (_nextOccurrences.TryGetValue(kind, out var cached) && cached > reference)
+        {
+            return cached;
+        }
+
+        var next = cron.GetNextOccurrence(reference.UtcDateTime, TimeZoneInfo.Utc);
+        if (next is null)
+        {
+            // No future occurrence; schedule far in future to avoid tight loop.
+            next = reference.UtcDateTime.AddYears(100);
+        }
+
+        var nextUtc = DateTime.SpecifyKind(next.Value, DateTimeKind.Utc);
+        var offset = new DateTimeOffset(nextUtc);
+        _nextOccurrences[kind] = offset;
+        return offset;
+    }
+
+    private async Task TriggerJobAsync(string kind, DateTimeOffset scheduledFor, CancellationToken stoppingToken)
+    {
+        var invokedAt = _timeProvider.GetUtcNow();
+        _diagnostics.RecordSchedulerSkew(kind, scheduledFor, invokedAt);
+
+        using var activity = _diagnostics.StartSchedulerActivity(kind, scheduledFor, invokedAt);
+        try
+        {
+            var result = await _coordinator.TriggerAsync(kind, parameters: null, trigger: "scheduler", stoppingToken).ConfigureAwait(false);
+            activity?.SetTag("job.trigger.outcome", result.Outcome.ToString());
+            if (result.Run is not null)
+            {
+                activity?.SetTag("job.run_id", result.Run.RunId);
+            }
+            if (!string.IsNullOrWhiteSpace(result.ErrorMessage))
+            {
+                activity?.SetTag("job.trigger.error", result.ErrorMessage);
+            }
+
+            if (result.Outcome == JobTriggerOutcome.Accepted)
+            {
+                activity?.SetStatus(ActivityStatusCode.Ok);
+            }
+            else
+            {
+                activity?.SetStatus(ActivityStatusCode.Ok, result.Outcome.ToString());
+            }
+
+            if (result.Outcome != JobTriggerOutcome.Accepted)
+            {
+                _logger.LogDebug("Scheduler trigger for {Kind} resulted in {Outcome}", kind, result.Outcome);
+            }
+        }
+        catch (Exception ex) when (!stoppingToken.IsCancellationRequested)
+        {
+            activity?.SetStatus(ActivityStatusCode.Error, ex.Message);
+            _logger.LogError(ex, "Cron trigger for job {Kind} failed", kind);
+        }
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobSchedulerOptions.cs

@@ -0,0 +1,12 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public sealed class JobSchedulerOptions
+{
+    public static JobSchedulerOptions Empty { get; } = new();
+
+    public IDictionary<string, JobDefinition> Definitions { get; } = new Dictionary<string, JobDefinition>(StringComparer.Ordinal);
+
+    public TimeSpan DefaultTimeout { get; set; } = TimeSpan.FromMinutes(15);
+
+    public TimeSpan DefaultLeaseDuration { get; set; } = TimeSpan.FromMinutes(5);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/JobTriggerResult.cs

@@ -0,0 +1,40 @@
+namespace StellaOps.Feedser.Core.Jobs;
+
+public enum JobTriggerOutcome
+{
+    Accepted,
+    NotFound,
+    Disabled,
+    AlreadyRunning,
+    LeaseRejected,
+    InvalidParameters,
+    Failed,
+    Cancelled,
+}
+
+public sealed record JobTriggerResult(JobTriggerOutcome Outcome, JobRunSnapshot? Run, string? ErrorMessage)
+{
+    public static JobTriggerResult Accepted(JobRunSnapshot run)
+        => new(JobTriggerOutcome.Accepted, run, null);
+
+    public static JobTriggerResult NotFound(string message)
+        => new(JobTriggerOutcome.NotFound, null, message);
+
+    public static JobTriggerResult Disabled(string message)
+        => new(JobTriggerOutcome.Disabled, null, message);
+
+    public static JobTriggerResult AlreadyRunning(string message)
+        => new(JobTriggerOutcome.AlreadyRunning, null, message);
+
+    public static JobTriggerResult LeaseRejected(string message)
+        => new(JobTriggerOutcome.LeaseRejected, null, message);
+
+    public static JobTriggerResult InvalidParameters(string message)
+        => new(JobTriggerOutcome.InvalidParameters, null, message);
+
+    public static JobTriggerResult Failed(JobRunSnapshot run, string error)
+        => new(JobTriggerOutcome.Failed, run, error);
+
+    public static JobTriggerResult Cancelled(JobRunSnapshot run, string error)
+        => new(JobTriggerOutcome.Cancelled, run, error);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/Jobs/ServiceCollectionExtensions.cs

@@ -0,0 +1,27 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
+
+namespace StellaOps.Feedser.Core.Jobs;
+
+public static class JobServiceCollectionExtensions
+{
+    public static JobSchedulerBuilder AddJobScheduler(this IServiceCollection services, Action<JobSchedulerOptions>? configure = null)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+
+        var optionsBuilder = services.AddOptions<JobSchedulerOptions>();
+        if (configure is not null)
+        {
+            optionsBuilder.Configure(configure);
+        }
+
+        services.AddSingleton(sp => sp.GetRequiredService<IOptions<JobSchedulerOptions>>().Value);
+        services.AddSingleton<JobDiagnostics>();
+        services.TryAddSingleton(TimeProvider.System);
+        services.AddSingleton<IJobCoordinator, JobCoordinator>();
+        services.AddHostedService<JobSchedulerHostedService>();
+
+        return new JobSchedulerBuilder(services);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Core/PluginBootstrapper.cs

@@ -1,61 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Reflection;
-using StellaOps.Plugin;
-
-namespace StellaOps.Feedser.Core;
-
-public static class PluginBootstrapper
-{
-    private static readonly string[] ConnectorPatterns =
-    {
-        "StellaOps.Feedser.Source.*.dll"
-    };
-
-    private static readonly string[] ExporterPatterns =
-    {
-        "StellaOps.Feedser.Exporter.*.dll"
-    };
-
-    public static IReadOnlyList<IConnectorPlugin> LoadConnectorPlugins(IServiceProvider? services = null, string? baseDirectory = null)
-    {
-        services ??= NullServiceProvider.Instance;
-        var catalog = BuildCatalog(baseDirectory, ConnectorPatterns);
-        return catalog.GetAvailableConnectorPlugins(services);
-    }
-
-    public static IReadOnlyList<IExporterPlugin> LoadExporterPlugins(IServiceProvider? services = null, string? baseDirectory = null)
-    {
-        services ??= NullServiceProvider.Instance;
-        var catalog = BuildCatalog(baseDirectory, ExporterPatterns);
-        return catalog.GetAvailableExporterPlugins(services);
-    }
-
-    private static PluginCatalog BuildCatalog(string? baseDirectory, IReadOnlyCollection<string> patterns)
-    {
-        var catalog = new PluginCatalog();
-
-        foreach (var assembly in AppDomain.CurrentDomain.GetAssemblies())
-        {
-            if (assembly.FullName is { } name && name.StartsWith("StellaOps.Feedser", StringComparison.OrdinalIgnoreCase))
-            {
-                catalog.AddAssembly(assembly);
-            }
-        }
-
-        baseDirectory ??= AppContext.BaseDirectory;
-        foreach (var pattern in patterns)
-        {
-            catalog.AddFromDirectory(baseDirectory, pattern);
-        }
-
-        return catalog;
-    }
-
-    private sealed class NullServiceProvider : IServiceProvider
-    {
-        public static NullServiceProvider Instance { get; } = new();
-        public object? GetService(Type serviceType) => null;
-    }
-}
-

src/StellaOps.Feedser/StellaOps.Feedser.Core/StellaOps.Feedser.Core.csproj

@@ -1,19 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
-
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
-
   <ItemGroup>
-    <ProjectReference Include="../StellaOps.Feedser.Models/StellaOps.Feedser.Models.csproj" />
-    <ProjectReference Include="../StellaOps.Feedser.Storage.Mongo/StellaOps.Feedser.Storage.Mongo.csproj" />
-    <ProjectReference Include="../StellaOps.Feedser.Normalization/StellaOps.Feedser.Normalization.csproj" />
-    <ProjectReference Include="../StellaOps.Feedser.Merge/StellaOps.Feedser.Merge.csproj" />
-    <ProjectReference Include="../StellaOps.Feedser.Exporter.Json/StellaOps.Feedser.Exporter.Json.csproj" />
-    <ProjectReference Include="../StellaOps.Feedser.Exporter.TrivyDb/StellaOps.Feedser.Exporter.TrivyDb.csproj" />
-    <ProjectReference Include="../../__Libraries/StellaOps.Plugin/StellaOps.Plugin.csproj" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="8.0.0" />
+    <PackageReference Include="Cronos" Version="0.10.0" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\StellaOps.Feedser.Models\StellaOps.Feedser.Models.csproj" />
   </ItemGroup>
 </Project>
-

src/StellaOps.Feedser/StellaOps.Feedser.Core/TASKS.md

@@ -0,0 +1,14 @@
+# TASKS
+| Task | Owner(s) | Depends on | Notes |
+|---|---|---|---|
+|JobCoordinator implementation (create/get/mark status)|BE-Core|Storage.Mongo|DONE – `JobCoordinator` drives Mongo-backed runs.|
+|Cron scheduling loop with TimeProvider|BE-Core|Core|DONE – `JobSchedulerHostedService` evaluates cron expressions.|
+|Single-flight/lease semantics|BE-Core|Storage.Mongo|DONE – lease acquisition backed by `MongoLeaseStore`.|
+|Trigger API contract (Result mapping)|BE-Core|WebService|DONE – `JobTriggerResult` outcomes map to HTTP statuses.|
+|Run telemetry enrichment|BE-Core|Observability|DONE – `JobDiagnostics` ties activities & counters into coordinator/scheduler paths.|
+|Deterministic params hashing|BE-Core|Core|DONE – `JobParametersHasher` creates SHA256 hash.|
+|Golden tests for timeout/cancel|QA|Core|DONE – JobCoordinatorTests cover cancellation timeout path.|
+|JobSchedulerBuilder options registry coverage|BE-Core|Core|TODO – verify cron/timeout/lease metadata persists for scheduler surfaces.|
+|Plugin discovery + DI glue with PluginHost|BE-Core|Plugin libs|TODO – auto-register job routines for connectors/exporters.|
+|Harden lease release error handling in JobCoordinator|BE-Core|Storage.Mongo|DONE – lease release failures now logged, wrapped, and drive run failure status; fire-and-forget execution guarded. Verified with `dotnet test --no-build --filter JobCoordinator`.|
+|Validate job trigger parameters for serialization|BE-Core|WebService|DONE – trigger parameters normalized/serialized with defensive checks returning InvalidParameters on failure. Full-suite `dotnet test --no-build` currently red from live connector fixture drift (Oracle/JVN/RedHat).|

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/AGENTS.md

@@ -0,0 +1,23 @@
+# AGENTS
+## Role
+Optional exporter producing vuln-list-shaped JSON tree for downstream trivy-db builder or interoperability. Deterministic, provenance-preserving.
+## Scope
+- Transform canonical advisories into directory tree structure mirroring aquasecurity/vuln-list (by ecosystem/vendor/distro as applicable).
+- Sorting and serialization invariants: stable key order, newline policy, UTC ISO-8601.
+- Cursoring/incremental export: export_state tracks last advisory hash/time to avoid full rewrites.
+- Packaging: output directory under exports/json/<timestamp> with reproducible naming; optionally symlink latest.
+- Optional auxiliary index files (for example severity summaries) may be generated when explicitly requested, but must remain deterministic and avoid altering canonical payloads.
+## Participants
+- Storage.Mongo.AdvisoryStore as input; ExportState repository for cursors/digests.
+- Core scheduler runs JsonExportJob; Plugin DI wires JsonExporter + job.
+- TrivyDb exporter may consume the rendered tree in v0 (builder path) if configured.
+## Interfaces & contracts
+- Job kind: export:json (JsonExportJob).
+- Determinism: same inputs -> identical file bytes; hash snapshot persisted.
+- Provenance: include minimal provenance fields when helpful; keep identity stable.
+## In/Out of scope
+In: JSON rendering and layout; incremental/deterministic writes.
+Out: ORAS push and Trivy DB BoltDB writing (owned by Trivy exporter).
+## Observability & security expectations
+- Metrics: export.json.records, bytes, duration, delta.changed.
+- Logs: target path, record counts, digest; no sensitive data.

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/Class1.cs

@@ -1,25 +0,0 @@
-using System;
-using System.Threading;
-using System.Threading.Tasks;
-using StellaOps.Plugin;
-
-namespace StellaOps.Feedser.Exporter.Json;
-
-public sealed class JsonExporterPlugin : IExporterPlugin
-{
-    public string Name => "json";
-
-    public bool IsAvailable(IServiceProvider services) => true;
-
-    public IFeedExporter Create(IServiceProvider services) => new StubExporter(Name);
-
-    private sealed class StubExporter : IFeedExporter
-    {
-        public StubExporter(string name) => Name = name;
-
-        public string Name { get; }
-
-        public Task ExportAsync(IServiceProvider services, CancellationToken cancellationToken) => Task.CompletedTask;
-    }
-}
-

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/ExportDigestCalculator.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public static class ExportDigestCalculator
+{
+    public static string ComputeTreeDigest(JsonExportResult result)
+    {
+        ArgumentNullException.ThrowIfNull(result);
+
+        using var sha256 = SHA256.Create();
+        var buffer = new byte[128 * 1024];
+
+        foreach (var file in result.FilePaths.OrderBy(static path => path, StringComparer.Ordinal))
+        {
+            var normalized = file.Replace("\\", "/");
+            var pathBytes = Encoding.UTF8.GetBytes(normalized);
+            _ = sha256.TransformBlock(pathBytes, 0, pathBytes.Length, null, 0);
+
+            var fullPath = ResolveFullPath(result.ExportDirectory, normalized);
+            using var stream = File.OpenRead(fullPath);
+            int read;
+            while ((read = stream.Read(buffer, 0, buffer.Length)) > 0)
+            {
+                _ = sha256.TransformBlock(buffer, 0, read, null, 0);
+            }
+        }
+
+        _ = sha256.TransformFinalBlock(Array.Empty<byte>(), 0, 0);
+        var hash = sha256.Hash ?? Array.Empty<byte>();
+        var hex = Convert.ToHexString(hash).ToLowerInvariant();
+        return $"sha256:{hex}";
+    }
+
+    private static string ResolveFullPath(string root, string normalizedRelativePath)
+    {
+        var segments = normalizedRelativePath.Split('/', StringSplitOptions.RemoveEmptyEntries);
+        var parts = new string[segments.Length + 1];
+        parts[0] = root;
+        for (var i = 0; i < segments.Length; i++)
+        {
+            parts[i + 1] = segments[i];
+        }
+
+        return Path.Combine(parts);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/ExporterVersion.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Reflection;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public static class ExporterVersion
+{
+    public static string GetVersion(Type anchor)
+    {
+        ArgumentNullException.ThrowIfNull(anchor);
+        var assembly = anchor.Assembly;
+
+        var informational = assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>()?.InformationalVersion;
+        if (!string.IsNullOrWhiteSpace(informational))
+        {
+            return informational;
+        }
+
+        var fileVersion = assembly.GetCustomAttribute<AssemblyFileVersionAttribute>()?.Version;
+        if (!string.IsNullOrWhiteSpace(fileVersion))
+        {
+            return fileVersion!;
+        }
+
+        var version = assembly.GetName().Version;
+        return version?.ToString() ?? "0.0.0";
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/IJsonExportPathResolver.cs

@@ -0,0 +1,12 @@
+using StellaOps.Feedser.Models;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public interface IJsonExportPathResolver
+{
+    /// <summary>
+    /// Returns the relative path (using platform directory separators) for the supplied advisory.
+    /// Path must not include the leading export root.
+    /// </summary>
+    string GetRelativePath(Advisory advisory);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExportFile.cs

@@ -0,0 +1,37 @@
+using System;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+/// <summary>
+/// Metadata describing a single file produced by the JSON exporter.
+/// </summary>
+public sealed class JsonExportFile
+{
+    public JsonExportFile(string relativePath, long length, string digest)
+    {
+        RelativePath = relativePath ?? throw new ArgumentNullException(nameof(relativePath));
+        if (relativePath.Length == 0)
+        {
+            throw new ArgumentException("Relative path cannot be empty.", nameof(relativePath));
+        }
+
+        if (length < 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(length));
+        }
+
+        Digest = digest ?? throw new ArgumentNullException(nameof(digest));
+        if (digest.Length == 0)
+        {
+            throw new ArgumentException("Digest cannot be empty.", nameof(digest));
+        }
+
+        Length = length;
+    }
+
+    public string RelativePath { get; }
+
+    public long Length { get; }
+
+    public string Digest { get; }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExportJob.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using StellaOps.Feedser.Core.Jobs;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public sealed class JsonExportJob : IJob
+{
+    public const string JobKind = "export:json";
+    public static readonly TimeSpan DefaultTimeout = TimeSpan.FromMinutes(10);
+    public static readonly TimeSpan DefaultLeaseDuration = TimeSpan.FromMinutes(5);
+
+    private readonly JsonFeedExporter _exporter;
+    private readonly ILogger<JsonExportJob> _logger;
+
+    public JsonExportJob(JsonFeedExporter exporter, ILogger<JsonExportJob> logger)
+    {
+        _exporter = exporter ?? throw new ArgumentNullException(nameof(exporter));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task ExecuteAsync(JobExecutionContext context, CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Executing JSON export job {RunId}", context.RunId);
+        await _exporter.ExportAsync(context.Services, cancellationToken).ConfigureAwait(false);
+        _logger.LogInformation("Completed JSON export job {RunId}", context.RunId);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExportManifestWriter.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+internal static class JsonExportManifestWriter
+{
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        WriteIndented = true,
+    };
+
+    public static async Task WriteAsync(
+        JsonExportResult result,
+        string digest,
+        string exporterVersion,
+        CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(result);
+        ArgumentException.ThrowIfNullOrEmpty(digest);
+        ArgumentException.ThrowIfNullOrEmpty(exporterVersion);
+
+        var exportId = Path.GetFileName(result.ExportDirectory);
+        var files = result.Files
+            .Select(static file => new JsonExportManifestFile(file.RelativePath.Replace("\\", "/", StringComparison.Ordinal), file.Length, file.Digest))
+            .ToArray();
+
+        var manifest = new JsonExportManifest(
+            exportId,
+            result.ExportedAt.UtcDateTime,
+            digest,
+            result.AdvisoryCount,
+            result.TotalBytes,
+            files.Length,
+            files,
+            exporterVersion);
+
+        var payload = JsonSerializer.SerializeToUtf8Bytes(manifest, SerializerOptions);
+        var manifestPath = Path.Combine(result.ExportDirectory, "manifest.json");
+        await File.WriteAllBytesAsync(manifestPath, payload, cancellationToken).ConfigureAwait(false);
+        File.SetLastWriteTimeUtc(manifestPath, result.ExportedAt.UtcDateTime);
+    }
+
+    private sealed record JsonExportManifest(
+        [property: JsonPropertyOrder(1)] string ExportId,
+        [property: JsonPropertyOrder(2)] DateTime GeneratedAt,
+        [property: JsonPropertyOrder(3)] string Digest,
+        [property: JsonPropertyOrder(4)] int AdvisoryCount,
+        [property: JsonPropertyOrder(5)] long TotalBytes,
+        [property: JsonPropertyOrder(6)] int FileCount,
+        [property: JsonPropertyOrder(7)] IReadOnlyList<JsonExportManifestFile> Files,
+        [property: JsonPropertyOrder(8)] string ExporterVersion);
+
+    private sealed record JsonExportManifestFile(
+        [property: JsonPropertyOrder(1)] string Path,
+        [property: JsonPropertyOrder(2)] long Bytes,
+        [property: JsonPropertyOrder(3)] string Digest);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExportOptions.cs

@@ -0,0 +1,34 @@
+using System.IO;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+/// <summary>
+/// Configuration for JSON exporter output paths and determinism controls.
+/// </summary>
+public sealed class JsonExportOptions
+{
+    /// <summary>
+    /// Root directory where exports are written. Default "exports/json".
+    /// </summary>
+    public string OutputRoot { get; set; } = Path.Combine("exports", "json");
+
+    /// <summary>
+    /// Format string applied to the export timestamp to produce the directory name.
+    /// </summary>
+    public string DirectoryNameFormat { get; set; } = "yyyyMMdd'T'HHmmss'Z'";
+
+    /// <summary>
+    /// Optional static name for the symlink (or directory junction) pointing at the most recent export.
+    /// </summary>
+    public string LatestSymlinkName { get; set; } = "latest";
+
+    /// <summary>
+    /// When true, attempts to re-point <see cref="LatestSymlinkName"/> after a successful export.
+    /// </summary>
+    public bool MaintainLatestSymlink { get; set; } = true;
+
+    /// <summary>
+    /// Optional repository identifier recorded alongside export state metadata.
+    /// </summary>
+    public string? TargetRepository { get; set; }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExportResult.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public sealed class JsonExportResult
+{
+    public JsonExportResult(
+        string exportDirectory,
+        DateTimeOffset exportedAt,
+        IEnumerable<JsonExportFile> files,
+        int advisoryCount,
+        long totalBytes)
+    {
+        if (string.IsNullOrWhiteSpace(exportDirectory))
+        {
+            throw new ArgumentException("Export directory must be provided.", nameof(exportDirectory));
+        }
+
+        ExportDirectory = exportDirectory;
+        ExportedAt = exportedAt;
+        AdvisoryCount = advisoryCount;
+        TotalBytes = totalBytes;
+
+        var list = (files ?? throw new ArgumentNullException(nameof(files)))
+            .Where(static file => file is not null)
+            .ToImmutableArray();
+
+        Files = list;
+        FilePaths = list.Select(static file => file.RelativePath).ToImmutableArray();
+    }
+
+    public string ExportDirectory { get; }
+
+    public DateTimeOffset ExportedAt { get; }
+
+    public ImmutableArray<JsonExportFile> Files { get; }
+
+    public ImmutableArray<string> FilePaths { get; }
+
+    public int AdvisoryCount { get; }
+
+    public long TotalBytes { get; }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExportSnapshotBuilder.cs

@@ -0,0 +1,239 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Runtime.CompilerServices;
+using System.Security.Cryptography;
+using System.Text;
+using System.Threading.Tasks;
+using StellaOps.Feedser.Models;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+/// <summary>
+/// Writes canonical advisory snapshots into a vuln-list style directory tree with deterministic ordering.
+/// </summary>
+public sealed class JsonExportSnapshotBuilder
+{
+    private static readonly Encoding Utf8NoBom = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false);
+    private readonly JsonExportOptions _options;
+    private readonly IJsonExportPathResolver _pathResolver;
+
+    public JsonExportSnapshotBuilder(JsonExportOptions options, IJsonExportPathResolver pathResolver)
+    {
+        _options = options ?? throw new ArgumentNullException(nameof(options));
+        _pathResolver = pathResolver ?? throw new ArgumentNullException(nameof(pathResolver));
+    }
+
+    public Task<JsonExportResult> WriteAsync(
+        IReadOnlyCollection<Advisory> advisories,
+        DateTimeOffset exportedAt,
+        string? exportName = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (advisories is null)
+        {
+            throw new ArgumentNullException(nameof(advisories));
+        }
+
+        return WriteAsync(EnumerateAsync(advisories, cancellationToken), exportedAt, exportName, cancellationToken);
+    }
+
+    public async Task<JsonExportResult> WriteAsync(
+        IAsyncEnumerable<Advisory> advisories,
+        DateTimeOffset exportedAt,
+        string? exportName = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (advisories is null)
+        {
+            throw new ArgumentNullException(nameof(advisories));
+        }
+
+        var exportDirectoryName = exportName ?? exportedAt.UtcDateTime.ToString(_options.DirectoryNameFormat, CultureInfo.InvariantCulture);
+        if (string.IsNullOrWhiteSpace(exportDirectoryName))
+        {
+            throw new InvalidOperationException("Export directory name resolved to an empty string.");
+        }
+
+        var exportRoot = EnsureDirectoryExists(Path.GetFullPath(_options.OutputRoot));
+        TrySetDirectoryTimestamp(exportRoot, exportedAt);
+        var exportDirectory = Path.Combine(exportRoot, exportDirectoryName);
+
+        if (Directory.Exists(exportDirectory))
+        {
+            Directory.Delete(exportDirectory, recursive: true);
+        }
+
+        Directory.CreateDirectory(exportDirectory);
+        TrySetDirectoryTimestamp(exportDirectory, exportedAt);
+
+        var seen = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        var files = new List<JsonExportFile>();
+        long totalBytes = 0L;
+        var advisoryCount = 0;
+
+        await foreach (var advisory in advisories.WithCancellation(cancellationToken))
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            advisoryCount++;
+            var entry = Resolve(advisory);
+            if (!seen.Add(entry.RelativePath))
+            {
+                throw new InvalidOperationException($"Multiple advisories resolved to the same path '{entry.RelativePath}'.");
+            }
+
+            var destination = Combine(exportDirectory, entry.Segments);
+            var destinationDirectory = Path.GetDirectoryName(destination);
+            if (!string.IsNullOrEmpty(destinationDirectory))
+            {
+                EnsureDirectoryExists(destinationDirectory);
+                TrySetDirectoryTimestamp(destinationDirectory, exportedAt);
+            }
+            var payload = SnapshotSerializer.ToSnapshot(entry.Advisory);
+            var bytes = Utf8NoBom.GetBytes(payload);
+
+            await File.WriteAllBytesAsync(destination, bytes, cancellationToken).ConfigureAwait(false);
+            File.SetLastWriteTimeUtc(destination, exportedAt.UtcDateTime);
+
+            var digest = ComputeDigest(bytes);
+            files.Add(new JsonExportFile(entry.RelativePath, bytes.LongLength, digest));
+            totalBytes += bytes.LongLength;
+        }
+
+        files.Sort(static (left, right) => string.CompareOrdinal(left.RelativePath, right.RelativePath));
+
+        return new JsonExportResult(exportDirectory, exportedAt, files, advisoryCount, totalBytes);
+    }
+
+    private static async IAsyncEnumerable<Advisory> EnumerateAsync(
+        IEnumerable<Advisory> advisories,
+        [EnumeratorCancellation] CancellationToken cancellationToken)
+    {
+        foreach (var advisory in advisories)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            yield return advisory;
+            await Task.Yield();
+        }
+    }
+
+    private static string EnsureDirectoryExists(string directory)
+    {
+        if (string.IsNullOrWhiteSpace(directory))
+        {
+            throw new ArgumentException("Directory path must be provided.", nameof(directory));
+        }
+
+        Directory.CreateDirectory(directory);
+        return directory;
+    }
+
+    private static string Combine(string root, IReadOnlyList<string> segments)
+    {
+        var parts = new string[segments.Count + 1];
+        parts[0] = root;
+        for (var i = 0; i < segments.Count; i++)
+        {
+            parts[i + 1] = segments[i];
+        }
+
+        return Path.Combine(parts);
+    }
+
+    private static void TrySetDirectoryTimestamp(string directory, DateTimeOffset timestamp)
+    {
+        try
+        {
+            Directory.SetLastWriteTimeUtc(directory, timestamp.UtcDateTime);
+        }
+        catch (IOException)
+        {
+            // Ignore failure to set timestamps; not critical for content determinism.
+        }
+        catch (UnauthorizedAccessException)
+        {
+            // Ignore permission issues when setting timestamps.
+        }
+        catch (PlatformNotSupportedException)
+        {
+            // Some platforms may not support this operation.
+        }
+    }
+
+    private PathResolution Resolve(Advisory advisory)
+    {
+        if (advisory is null)
+        {
+            throw new ArgumentNullException(nameof(advisory));
+        }
+
+        var relativePath = _pathResolver.GetRelativePath(advisory);
+        var segments = NormalizeRelativePath(relativePath);
+        var normalized = string.Join('/', segments);
+        return new PathResolution(advisory, normalized, segments);
+    }
+
+    private static string[] NormalizeRelativePath(string relativePath)
+    {
+        if (string.IsNullOrWhiteSpace(relativePath))
+        {
+            throw new InvalidOperationException("Path resolver returned an empty path.");
+        }
+
+        if (Path.IsPathRooted(relativePath))
+        {
+            throw new InvalidOperationException("Path resolver returned an absolute path; only relative paths are supported.");
+        }
+
+        var pieces = relativePath.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);
+        if (pieces.Length == 0)
+        {
+            throw new InvalidOperationException("Path resolver produced no path segments.");
+        }
+
+        var sanitized = new string[pieces.Length];
+        for (var i = 0; i < pieces.Length; i++)
+        {
+            var segment = pieces[i];
+            if (segment == "." || segment == "..")
+            {
+                throw new InvalidOperationException("Relative paths cannot include '.' or '..' segments.");
+            }
+
+            sanitized[i] = SanitizeSegment(segment);
+        }
+
+        return sanitized;
+    }
+
+    private static string SanitizeSegment(string segment)
+    {
+        var invalid = Path.GetInvalidFileNameChars();
+        Span<char> buffer = stackalloc char[segment.Length];
+        var count = 0;
+        foreach (var ch in segment)
+        {
+            if (ch == '/' || ch == '\\' || Array.IndexOf(invalid, ch) >= 0)
+            {
+                buffer[count++] = '_';
+            }
+            else
+            {
+                buffer[count++] = ch;
+            }
+        }
+
+        var sanitized = new string(buffer[..count]).Trim();
+        return string.IsNullOrEmpty(sanitized) ? "_" : sanitized;
+    }
+
+    private sealed record PathResolution(Advisory Advisory, string RelativePath, IReadOnlyList<string> Segments);
+
+    private static string ComputeDigest(ReadOnlySpan<byte> payload)
+    {
+        var hash = SHA256.HashData(payload);
+        var hex = Convert.ToHexString(hash).ToLowerInvariant();
+        return $"sha256:{hex}";
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExporterDependencyInjectionRoutine.cs

@@ -0,0 +1,59 @@
+using System;
+using System.IO;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
+using StellaOps.DependencyInjection;
+using StellaOps.Feedser.Core.Jobs;
+using StellaOps.Feedser.Storage.Mongo.Exporting;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public sealed class JsonExporterDependencyInjectionRoutine : IDependencyInjectionRoutine
+{
+    private const string ConfigurationSection = "feedser:exporters:json";
+
+    public IServiceCollection Register(IServiceCollection services, IConfiguration configuration)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(configuration);
+
+        services.TryAddSingleton<IJsonExportPathResolver, VulnListJsonExportPathResolver>();
+        services.TryAddSingleton<ExportStateManager>();
+
+        services.AddOptions<JsonExportOptions>()
+            .Bind(configuration.GetSection(ConfigurationSection))
+            .PostConfigure(static options =>
+            {
+                if (string.IsNullOrWhiteSpace(options.OutputRoot))
+                {
+                    options.OutputRoot = Path.Combine("exports", "json");
+                }
+
+                if (string.IsNullOrWhiteSpace(options.DirectoryNameFormat))
+                {
+                    options.DirectoryNameFormat = "yyyyMMdd'T'HHmmss'Z'";
+                }
+            });
+
+        services.AddSingleton<JsonFeedExporter>();
+        services.AddTransient<JsonExportJob>();
+
+        services.PostConfigure<JobSchedulerOptions>(options =>
+        {
+            if (!options.Definitions.ContainsKey(JsonExportJob.JobKind))
+            {
+                options.Definitions[JsonExportJob.JobKind] = new JobDefinition(
+                    JsonExportJob.JobKind,
+                    typeof(JsonExportJob),
+                    JsonExportJob.DefaultTimeout,
+                    JsonExportJob.DefaultLeaseDuration,
+                    null,
+                    true);
+            }
+        });
+
+        return services;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonExporterPlugin.cs

@@ -0,0 +1,23 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using StellaOps.Feedser.Storage.Mongo.Advisories;
+using StellaOps.Plugin;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public sealed class JsonExporterPlugin : IExporterPlugin
+{
+    public string Name => JsonFeedExporter.ExporterName;
+
+    public bool IsAvailable(IServiceProvider services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        return services.GetService<IAdvisoryStore>() is not null;
+    }
+
+    public IFeedExporter Create(IServiceProvider services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        return ActivatorUtilities.CreateInstance<JsonFeedExporter>(services);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/JsonFeedExporter.cs

@@ -0,0 +1,150 @@
+using System;
+using System.Globalization;
+using System.IO;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using StellaOps.Feedser.Storage.Mongo.Advisories;
+using StellaOps.Feedser.Storage.Mongo.Exporting;
+using StellaOps.Plugin;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+public sealed class JsonFeedExporter : IFeedExporter
+{
+    public const string ExporterName = "json";
+    public const string ExporterId = "export:json";
+
+    private readonly IAdvisoryStore _advisoryStore;
+    private readonly JsonExportOptions _options;
+    private readonly IJsonExportPathResolver _pathResolver;
+    private readonly ExportStateManager _stateManager;
+    private readonly ILogger<JsonFeedExporter> _logger;
+    private readonly TimeProvider _timeProvider;
+    private readonly string _exporterVersion;
+
+    public JsonFeedExporter(
+        IAdvisoryStore advisoryStore,
+        IOptions<JsonExportOptions> options,
+        IJsonExportPathResolver pathResolver,
+        ExportStateManager stateManager,
+        ILogger<JsonFeedExporter> logger,
+        TimeProvider? timeProvider = null)
+    {
+        _advisoryStore = advisoryStore ?? throw new ArgumentNullException(nameof(advisoryStore));
+        _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+        _pathResolver = pathResolver ?? throw new ArgumentNullException(nameof(pathResolver));
+        _stateManager = stateManager ?? throw new ArgumentNullException(nameof(stateManager));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        _timeProvider = timeProvider ?? TimeProvider.System;
+        _exporterVersion = ExporterVersion.GetVersion(typeof(JsonFeedExporter));
+    }
+
+    public string Name => ExporterName;
+
+    public async Task ExportAsync(IServiceProvider services, CancellationToken cancellationToken)
+    {
+        var exportedAt = _timeProvider.GetUtcNow();
+        var exportId = exportedAt.ToString(_options.DirectoryNameFormat, CultureInfo.InvariantCulture);
+        var exportRoot = Path.GetFullPath(_options.OutputRoot);
+
+        _logger.LogInformation("Starting JSON export {ExportId}", exportId);
+
+        var existingState = await _stateManager.GetAsync(ExporterId, cancellationToken).ConfigureAwait(false);
+
+        var builder = new JsonExportSnapshotBuilder(_options, _pathResolver);
+        var advisoryStream = _advisoryStore.StreamAsync(cancellationToken);
+        var result = await builder.WriteAsync(advisoryStream, exportedAt, exportId, cancellationToken).ConfigureAwait(false);
+
+        var digest = ExportDigestCalculator.ComputeTreeDigest(result);
+        _logger.LogInformation(
+            "JSON export {ExportId} wrote {FileCount} files ({Bytes} bytes) covering {AdvisoryCount} advisories with digest {Digest}",
+            exportId,
+            result.Files.Length,
+            result.TotalBytes,
+            result.AdvisoryCount,
+            digest);
+
+        if (existingState is not null && string.Equals(existingState.LastFullDigest, digest, StringComparison.Ordinal))
+        {
+            _logger.LogInformation("JSON export {ExportId} produced unchanged digest; skipping state update.", exportId);
+            TryDeleteDirectory(result.ExportDirectory);
+            return;
+        }
+
+        await _stateManager.StoreFullExportAsync(
+            ExporterId,
+            exportId,
+            digest,
+            cursor: digest,
+            targetRepository: _options.TargetRepository,
+            exporterVersion: _exporterVersion,
+            cancellationToken: cancellationToken).ConfigureAwait(false);
+
+        await JsonExportManifestWriter.WriteAsync(result, digest, _exporterVersion, cancellationToken).ConfigureAwait(false);
+
+        if (_options.MaintainLatestSymlink)
+        {
+            TryUpdateLatestSymlink(exportRoot, result.ExportDirectory);
+        }
+    }
+
+    private void TryUpdateLatestSymlink(string exportRoot, string exportDirectory)
+    {
+        if (string.IsNullOrWhiteSpace(_options.LatestSymlinkName))
+        {
+            return;
+        }
+
+        var latestPath = Path.Combine(exportRoot, _options.LatestSymlinkName);
+
+        try
+        {
+            if (Directory.Exists(latestPath) || File.Exists(latestPath))
+            {
+                TryRemoveExistingPointer(latestPath);
+            }
+
+            Directory.CreateSymbolicLink(latestPath, exportDirectory);
+            _logger.LogDebug("Updated latest JSON export pointer to {Target}", exportDirectory);
+        }
+        catch (Exception ex) when (ex is IOException or UnauthorizedAccessException or PlatformNotSupportedException)
+        {
+            _logger.LogWarning(ex, "Failed to update latest JSON export pointer at {LatestPath}", latestPath);
+        }
+    }
+
+    private void TryRemoveExistingPointer(string latestPath)
+    {
+        try
+        {
+            var attributes = File.GetAttributes(latestPath);
+            if (attributes.HasFlag(FileAttributes.Directory))
+            {
+                Directory.Delete(latestPath, recursive: false);
+            }
+            else
+            {
+                File.Delete(latestPath);
+            }
+        }
+        catch (Exception ex) when (ex is IOException or UnauthorizedAccessException)
+        {
+            _logger.LogWarning(ex, "Failed to remove existing latest pointer {LatestPath}", latestPath);
+        }
+    }
+
+    private void TryDeleteDirectory(string path)
+    {
+        try
+        {
+            if (Directory.Exists(path))
+            {
+                Directory.Delete(path, recursive: true);
+            }
+        }
+        catch (Exception ex) when (ex is IOException or UnauthorizedAccessException)
+        {
+            _logger.LogWarning(ex, "Failed to remove unchanged export directory {ExportDirectory}", path);
+        }
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/StellaOps.Feedser.Exporter.Json.csproj

@@ -1,14 +1,22 @@
+<?xml version='1.0' encoding='utf-8'?>
 <Project Sdk="Microsoft.NET.Sdk">
-
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
-
   <ItemGroup>
-    <ProjectReference Include="../../__Libraries/StellaOps.Plugin/StellaOps.Plugin.csproj" />
-    <ProjectReference Include="../StellaOps.Feedser.Models/StellaOps.Feedser.Models.csproj" />
+    <ProjectReference Include="..\StellaOps.Feedser.Models\StellaOps.Feedser.Models.csproj" />
+    <ProjectReference Include="..\StellaOps.Feedser.Normalization\StellaOps.Feedser.Normalization.csproj" />
+    <ProjectReference Include="..\StellaOps.Feedser.Storage.Mongo\StellaOps.Feedser.Storage.Mongo.csproj" />
+    <ProjectReference Include="..\..\__Libraries\StellaOps.Plugin\StellaOps.Plugin.csproj" />
+    <ProjectReference Include="..\..\__Libraries\StellaOps.DependencyInjection\StellaOps.DependencyInjection.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="8.0.0" />
   </ItemGroup>
 </Project>
-

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/TASKS.md

@@ -0,0 +1,11 @@
+# TASKS
+| Task | Owner(s) | Depends on | Notes |
+|---|---|---|---|
+|Directory layout strategy (vuln-list mirror)|BE-Export|Models|DONE – `VulnListJsonExportPathResolver` maps CVE, GHSA, distro, and vendor identifiers into vuln-list style paths.|
+|Deterministic serializer|BE-Export|Models|DONE – Canonical serializer + snapshot builder emit stable JSON across runs.|
+|ExportState read/write|BE-Export|Storage.Mongo|DONE – `JsonFeedExporter` reads prior state, stores digests/cursors, and skips unchanged exports.|
+|JsonExportJob wiring|BE-Export|Core|DONE – Job scheduler options now configurable via DI; JSON job registered with scheduler.|
+|Snapshot tests for file tree|QA|Exporters|DONE – Added resolver/exporter tests asserting tree layout and deterministic behavior.|
+|Parity smoke vs upstream vuln-list|QA|Exporters|DONE – `JsonExporterParitySmokeTests` covers common ecosystems against vuln-list layout.|
+|Stream advisories during export|BE-Export|Storage.Mongo|DONE – exporter + streaming-only test ensures single enumeration and per-file digest capture.|
+|Emit export manifest with digest metadata|BE-Export|Exporters|DONE – manifest now includes per-file digests/sizes alongside tree digest.|

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.Json/VulnListJsonExportPathResolver.cs

@@ -0,0 +1,455 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using StellaOps.Feedser.Models;
+using StellaOps.Feedser.Normalization.Identifiers;
+
+namespace StellaOps.Feedser.Exporter.Json;
+
+/// <summary>
+/// Path resolver approximating the directory layout used by aquasecurity/vuln-list.
+/// Handles common vendor, distro, and ecosystem shapes with deterministic fallbacks.
+/// </summary>
+public sealed class VulnListJsonExportPathResolver : IJsonExportPathResolver
+{
+    private static readonly Regex CvePattern = new("^CVE-(?<year>\\d{4})-(?<id>\\d{4,})$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex GhsaPattern = new("^GHSA-[0-9a-z]{4}-[0-9a-z]{4}-[0-9a-z]{4}$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex UsnPattern = new("^USN-(?<id>\\d+-\\d+)(?<suffix>[a-z])?$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex DebianPattern = new("^(?<prefix>DLA|DSA|ELA)-(?<id>\\d+-\\d+)$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex RedHatPattern = new("^RH(?<type>SA|BA|EA)-(?<rest>[0-9:.-]+)$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex AmazonPattern = new("^ALAS(?<channel>2|2022|2023)?-(?<rest>[0-9A-Za-z:._-]+)$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex OraclePattern = new("^(?<kind>ELSA|ELBA|ELSA-OCI|ELBA-OCI)-(?<rest>[0-9A-Za-z:._-]+)$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex PhotonPattern = new("^PHSA-(?<rest>[0-9A-Za-z:._-]+)$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex RockyPattern = new("^RLSA-(?<rest>[0-9A-Za-z:._-]+)$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex SusePattern = new("^SUSE-(?<kind>SU|RU|OU|SB)-(?<rest>[0-9A-Za-z:._-]+)$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+
+    private static readonly Dictionary<string, string[]> SourceDirectoryMap = new(StringComparer.OrdinalIgnoreCase)
+    {
+        ["nvd"] = new[] { "nvd" },
+        ["ghsa"] = new[] { "ghsa" },
+        ["github"] = new[] { "ghsa" },
+        ["osv"] = new[] { "osv" },
+        ["redhat"] = new[] { "redhat", "oval" },
+        ["ubuntu"] = new[] { "ubuntu" },
+        ["debian"] = new[] { "debian" },
+        ["oracle"] = new[] { "oracle" },
+        ["photon"] = new[] { "photon" },
+        ["rocky"] = new[] { "rocky" },
+        ["suse"] = new[] { "suse" },
+        ["amazon"] = new[] { "amazon" },
+        ["aws"] = new[] { "amazon" },
+        ["alpine"] = new[] { "alpine" },
+        ["wolfi"] = new[] { "wolfi" },
+        ["chainguard"] = new[] { "chainguard" },
+        ["cert-fr"] = new[] { "cert", "fr" },
+        ["cert-in"] = new[] { "cert", "in" },
+        ["cert-cc"] = new[] { "cert", "cc" },
+        ["cert-bund"] = new[] { "cert", "bund" },
+        ["cisa"] = new[] { "ics", "cisa" },
+        ["ics-cisa"] = new[] { "ics", "cisa" },
+        ["ics-kaspersky"] = new[] { "ics", "kaspersky" },
+        ["kaspersky"] = new[] { "ics", "kaspersky" },
+    };
+
+    private static readonly Dictionary<string, string> GhsaEcosystemMap = new(StringComparer.OrdinalIgnoreCase)
+    {
+        ["go"] = "go",
+        ["golang"] = "go",
+        ["npm"] = "npm",
+        ["maven"] = "maven",
+        ["pypi"] = "pip",
+        ["pip"] = "pip",
+        ["nuget"] = "nuget",
+        ["composer"] = "composer",
+        ["packagist"] = "composer",
+        ["rubygems"] = "rubygems",
+        ["gem"] = "rubygems",
+        ["swift"] = "swift",
+        ["cargo"] = "cargo",
+        ["hex"] = "hex",
+        ["pub"] = "pub",
+        ["github"] = "github",
+        ["docker"] = "container",
+    };
+
+    public string GetRelativePath(Advisory advisory)
+    {
+        if (advisory is null)
+        {
+            throw new ArgumentNullException(nameof(advisory));
+        }
+
+        var identifier = SelectPreferredIdentifier(advisory);
+        if (identifier.Length == 0)
+        {
+            throw new InvalidOperationException("Unable to derive identifier for advisory.");
+        }
+
+        var layout = ResolveLayout(advisory, identifier);
+        var segments = new string[layout.Segments.Length + 1];
+        for (var i = 0; i < layout.Segments.Length; i++)
+        {
+            segments[i] = layout.Segments[i];
+        }
+        segments[^1] = layout.FileName;
+        return Path.Combine(segments);
+    }
+
+    private static Layout ResolveLayout(Advisory advisory, string identifier)
+    {
+        if (TryResolveCve(identifier, out var layout))
+        {
+            return layout;
+        }
+
+        if (TryResolveGhsa(advisory, identifier, out layout))
+        {
+            return layout;
+        }
+
+        if (TryResolveUsn(identifier, out layout) ||
+            TryResolveDebian(identifier, out layout) ||
+            TryResolveRedHat(identifier, out layout) ||
+            TryResolveAmazon(identifier, out layout) ||
+            TryResolveOracle(identifier, out layout) ||
+            TryResolvePhoton(identifier, out layout) ||
+            TryResolveRocky(identifier, out layout) ||
+            TryResolveSuse(identifier, out layout))
+        {
+            return layout;
+        }
+
+        if (TryResolveByProvenance(advisory, identifier, out layout))
+        {
+            return layout;
+        }
+
+        return new Layout(new[] { "misc" }, CreateFileName(identifier));
+    }
+
+    private static bool TryResolveCve(string identifier, out Layout layout)
+    {
+        var match = CvePattern.Match(identifier);
+        if (!match.Success)
+        {
+            layout = default;
+            return false;
+        }
+
+        var year = match.Groups["year"].Value;
+        layout = new Layout(new[] { "nvd", year }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveGhsa(Advisory advisory, string identifier, out Layout layout)
+    {
+        if (!GhsaPattern.IsMatch(identifier))
+        {
+            layout = default;
+            return false;
+        }
+
+        if (TryGetGhsaPackage(advisory, out var ecosystem, out var packagePath))
+        {
+            layout = new Layout(new[] { "ghsa", ecosystem, packagePath }, CreateFileName(identifier, uppercase: true));
+            return true;
+        }
+
+        layout = new Layout(new[] { "github", "advisories" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveUsn(string identifier, out Layout layout)
+    {
+        if (!UsnPattern.IsMatch(identifier))
+        {
+            layout = default;
+            return false;
+    }
+
+        layout = new Layout(new[] { "ubuntu" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveDebian(string identifier, out Layout layout)
+    {
+        var match = DebianPattern.Match(identifier);
+        if (!match.Success)
+        {
+            layout = default;
+            return false;
+        }
+
+        layout = new Layout(new[] { "debian" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveRedHat(string identifier, out Layout layout)
+    {
+        if (!RedHatPattern.IsMatch(identifier))
+        {
+            layout = default;
+            return false;
+        }
+
+        layout = new Layout(new[] { "redhat", "oval" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveAmazon(string identifier, out Layout layout)
+    {
+        var match = AmazonPattern.Match(identifier);
+        if (!match.Success)
+        {
+            layout = default;
+            return false;
+        }
+
+        var channel = match.Groups["channel"].Value;
+        var subdirectory = channel switch
+        {
+            "2" => "2",
+            "2023" => "2023",
+            "2022" => "2022",
+            _ => "1",
+        };
+
+        layout = new Layout(new[] { "amazon", subdirectory }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveOracle(string identifier, out Layout layout)
+    {
+        if (!OraclePattern.IsMatch(identifier))
+        {
+            layout = default;
+            return false;
+        }
+
+        layout = new Layout(new[] { "oracle", "linux" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolvePhoton(string identifier, out Layout layout)
+    {
+        if (!PhotonPattern.IsMatch(identifier))
+        {
+            layout = default;
+            return false;
+        }
+
+        layout = new Layout(new[] { "photon" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveRocky(string identifier, out Layout layout)
+    {
+        if (!RockyPattern.IsMatch(identifier))
+        {
+            layout = default;
+            return false;
+        }
+
+        layout = new Layout(new[] { "rocky" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveSuse(string identifier, out Layout layout)
+    {
+        if (!SusePattern.IsMatch(identifier))
+        {
+            layout = default;
+            return false;
+        }
+
+        layout = new Layout(new[] { "suse" }, CreateFileName(identifier, uppercase: true));
+        return true;
+    }
+
+    private static bool TryResolveByProvenance(Advisory advisory, string identifier, out Layout layout)
+    {
+        foreach (var source in EnumerateDistinctProvenanceSources(advisory))
+        {
+            if (SourceDirectoryMap.TryGetValue(source, out var segments))
+            {
+                layout = new Layout(segments, CreateFileName(identifier));
+                return true;
+            }
+        }
+
+        layout = default;
+        return false;
+    }
+
+    private static bool TryGetGhsaPackage(Advisory advisory, out string ecosystem, out string packagePath)
+    {
+        foreach (var package in advisory.AffectedPackages)
+        {
+            if (!TryParsePackageUrl(package.Identifier, out var type, out var encodedPath))
+            {
+                continue;
+            }
+
+            if (GhsaEcosystemMap.TryGetValue(type, out var mapped))
+            {
+                ecosystem = mapped;
+            }
+            else
+            {
+                ecosystem = type.ToLowerInvariant();
+            }
+
+            packagePath = encodedPath;
+            return true;
+        }
+
+        ecosystem = "advisories";
+        packagePath = "_";
+        return false;
+    }
+
+    private static bool TryParsePackageUrl(string identifier, out string type, out string encodedPath)
+    {
+        type = string.Empty;
+        encodedPath = string.Empty;
+
+        if (!IdentifierNormalizer.TryNormalizePackageUrl(identifier, out _, out var packageUrl))
+        {
+            return false;
+        }
+
+        var segments = packageUrl!.NamespaceSegments.IsDefaultOrEmpty
+            ? new[] { packageUrl.Name }
+            : packageUrl.NamespaceSegments.Append(packageUrl.Name).ToArray();
+
+        type = packageUrl.Type;
+        encodedPath = string.Join("%2F", segments);
+        return true;
+    }
+
+    private static string CreateFileName(string identifier, bool uppercase = false)
+    {
+        var candidate = uppercase ? identifier.ToUpperInvariant() : identifier;
+        return $"{SanitizeFileName(candidate)}.json";
+    }
+
+    private static IEnumerable<string> EnumerateDistinctProvenanceSources(Advisory advisory)
+    {
+        var seen = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+        foreach (var source in advisory.Provenance)
+        {
+            if (TryAddSource(source.Source))
+            {
+                yield return source.Source;
+            }
+        }
+
+        foreach (var reference in advisory.References)
+        {
+            if (TryAddSource(reference.Provenance.Source))
+            {
+                yield return reference.Provenance.Source;
+            }
+        }
+
+        foreach (var package in advisory.AffectedPackages)
+        {
+            foreach (var source in package.Provenance)
+            {
+                if (TryAddSource(source.Source))
+                {
+                    yield return source.Source;
+                }
+            }
+
+            foreach (var range in package.VersionRanges)
+            {
+                if (TryAddSource(range.Provenance.Source))
+                {
+                    yield return range.Provenance.Source;
+                }
+            }
+        }
+
+        foreach (var metric in advisory.CvssMetrics)
+        {
+            if (TryAddSource(metric.Provenance.Source))
+            {
+                yield return metric.Provenance.Source;
+            }
+        }
+
+        bool TryAddSource(string? value)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                return false;
+            }
+
+            return seen.Add(value);
+        }
+    }
+
+    private static string SelectPreferredIdentifier(Advisory advisory)
+    {
+        if (TrySelectIdentifier(advisory.AdvisoryKey, out var preferred))
+        {
+            return preferred;
+        }
+
+        foreach (var alias in advisory.Aliases)
+        {
+            if (TrySelectIdentifier(alias, out preferred))
+            {
+                return preferred;
+            }
+        }
+
+        return advisory.AdvisoryKey.Trim();
+    }
+
+    private static bool TrySelectIdentifier(string value, out string identifier)
+    {
+        identifier = string.Empty;
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            return false;
+        }
+
+        var trimmed = value.Trim();
+        if (CvePattern.IsMatch(trimmed) || GhsaPattern.IsMatch(trimmed))
+        {
+            identifier = trimmed;
+            return true;
+        }
+
+        identifier = trimmed;
+        return false;
+    }
+
+    private static string SanitizeFileName(string name)
+    {
+        var invalid = Path.GetInvalidFileNameChars();
+        Span<char> buffer = stackalloc char[name.Length];
+        var count = 0;
+        foreach (var ch in name)
+        {
+            if (ch == '/' || ch == '\\' || Array.IndexOf(invalid, ch) >= 0)
+            {
+                buffer[count++] = '_';
+            }
+            else
+            {
+                buffer[count++] = ch;
+            }
+        }
+
+        var sanitized = new string(buffer[..count]).Trim();
+        return string.IsNullOrEmpty(sanitized) ? "advisory" : sanitized;
+    }
+
+    private readonly record struct Layout(string[] Segments, string FileName);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/AGENTS.md

@@ -0,0 +1,24 @@
+# AGENTS
+## Role
+Exporter producing a Trivy-compatible database artifact for self-hosting or offline use. v0: JSON list + metadata; v1: integrate official trivy-db builder or write BoltDB directly; pack and optionally push via ORAS.
+## Scope
+- Read canonical advisories; serialize payload for builder or intermediate; write metadata.json (generatedAt, counts).
+- Output root: exports/trivy/<yyyyMMddHHmmss>; deterministic path components.
+- OCI/Trivy expectations: layer media type application/vnd.aquasec.trivy.db.layer.v1.tar+gzip; config media type application/vnd.aquasec.trivy.config.v1+json; tag (e.g., 2).
+- Optional ORAS push; optional offline bundle (db.tar.gz + metadata.json).
+- DI: TrivyExporter + Jobs.TrivyExportJob registered by TrivyExporterDependencyInjectionRoutine.
+- Export_state recording: capture digests, counts, start/end timestamps for idempotent reruns and incremental packaging.
+## Participants
+- Storage.Mongo.AdvisoryStore as input.
+- Core scheduler runs export job; WebService/Plugins trigger it.
+- JSON exporter (optional precursor) if choosing the builder path.
+## Interfaces & contracts
+- IFeedExporter.Name = "trivy-db"; ExportAsync(IServiceProvider, CancellationToken).
+- FeedserOptions.packaging.trivy governs repo/tag/publish/offline_bundle.
+- Deterministic sorting and timestamp discipline (UTC; consider build reproducibility knobs).
+## In/Out of scope
+In: assembling builder inputs, packing tar.gz, pushing to registry when configured.
+Out: signing (external pipeline), scanner behavior.
+## Observability & security expectations
+- Metrics: export.trivy.records, size_bytes, duration, oras.push.success/fail.
+- Logs: export path, repo/tag, digest; redact credentials; backoff on push errors.

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/Class1.cs

@@ -1,25 +0,0 @@
-using System;
-using System.Threading;
-using System.Threading.Tasks;
-using StellaOps.Plugin;
-
-namespace StellaOps.Feedser.Exporter.TrivyDb;
-
-public sealed class TrivyDbExporterPlugin : IExporterPlugin
-{
-    public string Name => "trivydb";
-
-    public bool IsAvailable(IServiceProvider services) => true;
-
-    public IFeedExporter Create(IServiceProvider services) => new StubExporter(Name);
-
-    private sealed class StubExporter : IFeedExporter
-    {
-        public StubExporter(string name) => Name = name;
-
-        public string Name { get; }
-
-        public Task ExportAsync(IServiceProvider services, CancellationToken cancellationToken) => Task.CompletedTask;
-    }
-}
-

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/ITrivyDbBuilder.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using StellaOps.Feedser.Exporter.Json;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public interface ITrivyDbBuilder
+{
+    Task<TrivyDbBuilderResult> BuildAsync(
+        JsonExportResult jsonTree,
+        DateTimeOffset exportedAt,
+        string exportId,
+        CancellationToken cancellationToken);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/ITrivyDbOrasPusher.cs

@@ -0,0 +1,9 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public interface ITrivyDbOrasPusher
+{
+    Task PushAsync(string layoutPath, string reference, string exportId, CancellationToken cancellationToken);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/OciDescriptor.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record OciDescriptor(
+    [property: JsonPropertyName("mediaType")] string MediaType,
+    [property: JsonPropertyName("digest")] string Digest,
+    [property: JsonPropertyName("size")] long Size,
+    [property: JsonPropertyName("annotations")] IReadOnlyDictionary<string, string>? Annotations = null);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/OciIndex.cs

@@ -0,0 +1,8 @@
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record OciIndex(
+    [property: JsonPropertyName("schemaVersion")] int SchemaVersion,
+    [property: JsonPropertyName("manifests")] IReadOnlyList<OciDescriptor> Manifests);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/OciManifest.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record OciManifest(
+    [property: JsonPropertyName("schemaVersion")] int SchemaVersion,
+    [property: JsonPropertyName("mediaType")] string MediaType,
+    [property: JsonPropertyName("config")] OciDescriptor Config,
+    [property: JsonPropertyName("layers")] IReadOnlyList<OciDescriptor> Layers);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/StellaOps.Feedser.Exporter.TrivyDb.csproj

@@ -1,14 +1,22 @@
+<?xml version='1.0' encoding='utf-8'?>
 <Project Sdk="Microsoft.NET.Sdk">
-
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
-
   <ItemGroup>
-    <ProjectReference Include="../../__Libraries/StellaOps.Plugin/StellaOps.Plugin.csproj" />
-    <ProjectReference Include="../StellaOps.Feedser.Models/StellaOps.Feedser.Models.csproj" />
+    <ProjectReference Include="..\StellaOps.Feedser.Exporter.Json\StellaOps.Feedser.Exporter.Json.csproj" />
+    <ProjectReference Include="..\StellaOps.Feedser.Models\StellaOps.Feedser.Models.csproj" />
+    <ProjectReference Include="..\StellaOps.Feedser.Storage.Mongo\StellaOps.Feedser.Storage.Mongo.csproj" />
+    <ProjectReference Include="..\..\__Libraries\StellaOps.DependencyInjection\StellaOps.DependencyInjection.csproj" />
+    <ProjectReference Include="..\..\__Libraries\StellaOps.Plugin\StellaOps.Plugin.csproj" />
   </ItemGroup>
-</Project>
-
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="8.0.0" />
+  </ItemGroup>
+</Project>

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TASKS.md

@@ -0,0 +1,13 @@
+# TASKS
+| Task | Owner(s) | Depends on | Notes |
+|---|---|---|---|
+|Fix method name typo GetExportRoot' -> GetExportRoot|BE-Export|Exporters|DONE – `TrivyDbExportOptions.GetExportRoot` helper added with unit coverage.|
+|Implement BoltDB builder integration (v0 via trivy-db CLI)|BE-Export|Env|DONE – `TrivyDbBoltBuilder` shells `trivy-db build` against our JSON tree with deterministic packaging.|
+|Pack db.tar.gz + metadata.json|BE-Export|Exporters|DONE – Builder output re-packed with fixed timestamps and zeroed gzip mtime.|
+|ORAS push support|BE-Export|Exporters|DONE – Optional `TrivyDbOrasPusher` shells `oras cp --from-oci-layout` with configurable args/env.|
+|Offline bundle toggle|BE-Export|Exporters|DONE – Deterministic OCI layout bundle emitted when enabled.|
+|Deterministic ordering of advisories|BE-Export|Models|TODO – Sort by advisoryKey; stable array orders.|
+|End-to-end tests with small dataset|QA|Exporters|TODO – Assert media types and reproducible digests across runs.|
+|ExportState persistence & idempotence|BE-Export|Storage.Mongo|DOING – `ExportStateManager` keeps stable base export metadata; delta reset remains pending.|
+|Streamed package building to avoid large copies|BE-Export|Exporters|TODO – refactor package writer to stream without double-buffering metadata/archive payloads.|
+|Plan incremental/delta exports|BE-Export|Exporters|TODO – design reuse of existing blobs/layers when inputs unchanged instead of rewriting full trees each run.|

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyConfigDocument.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record TrivyConfigDocument(
+    [property: JsonPropertyName("mediaType")] string MediaType,
+    [property: JsonPropertyName("generatedAt")] DateTimeOffset GeneratedAt,
+    [property: JsonPropertyName("databaseVersion")] string DatabaseVersion,
+    [property: JsonPropertyName("databaseDigest")] string DatabaseDigest,
+    [property: JsonPropertyName("databaseSize")] long DatabaseSize);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbBlob.cs

@@ -0,0 +1,62 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbBlob
+{
+    private readonly Func<CancellationToken, ValueTask<Stream>> _openReadAsync;
+
+    private TrivyDbBlob(Func<CancellationToken, ValueTask<Stream>> openReadAsync, long length)
+    {
+        _openReadAsync = openReadAsync ?? throw new ArgumentNullException(nameof(openReadAsync));
+        if (length < 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(length));
+        }
+
+        Length = length;
+    }
+
+    public long Length { get; }
+
+    public ValueTask<Stream> OpenReadAsync(CancellationToken cancellationToken)
+        => _openReadAsync(cancellationToken);
+
+    public static TrivyDbBlob FromBytes(ReadOnlyMemory<byte> payload)
+    {
+        if (payload.IsEmpty)
+        {
+            return new TrivyDbBlob(static _ => ValueTask.FromResult<Stream>(Stream.Null), 0);
+        }
+
+        return new TrivyDbBlob(
+            cancellationToken => ValueTask.FromResult<Stream>(new MemoryStream(payload.ToArray(), writable: false)),
+            payload.Length);
+    }
+
+    public static TrivyDbBlob FromFile(string path, long length)
+    {
+        if (string.IsNullOrWhiteSpace(path))
+        {
+            throw new ArgumentException("File path must be provided.", nameof(path));
+        }
+
+        if (length < 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(length));
+        }
+
+        return new TrivyDbBlob(
+            cancellationToken => ValueTask.FromResult<Stream>(new FileStream(
+                path,
+                FileMode.Open,
+                FileAccess.Read,
+                FileShare.Read,
+                bufferSize: 81920,
+                options: FileOptions.Asynchronous | FileOptions.SequentialScan)),
+            length);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbBoltBuilder.cs

@@ -0,0 +1,376 @@
+using System;
+using System.Diagnostics;
+using System.Globalization;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Formats.Tar;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using StellaOps.Feedser.Exporter.Json;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbBoltBuilder : ITrivyDbBuilder
+{
+    private readonly TrivyDbExportOptions _options;
+    private readonly ILogger<TrivyDbBoltBuilder> _logger;
+
+    public TrivyDbBoltBuilder(IOptions<TrivyDbExportOptions> options, ILogger<TrivyDbBoltBuilder> logger)
+    {
+        _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task<TrivyDbBuilderResult> BuildAsync(
+        JsonExportResult jsonTree,
+        DateTimeOffset exportedAt,
+        string exportId,
+        CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(jsonTree);
+        ArgumentException.ThrowIfNullOrEmpty(exportId);
+
+        var builderRoot = PrepareBuilderRoot(jsonTree.ExportDirectory, exportId);
+        var outputDir = Path.Combine(builderRoot, "out");
+        Directory.CreateDirectory(outputDir);
+
+        try
+        {
+            await RunCliAsync(jsonTree.ExportDirectory, outputDir, cancellationToken).ConfigureAwait(false);
+        }
+        catch
+        {
+            TryDeleteDirectory(builderRoot);
+            throw;
+        }
+
+        var metadataPath = Path.Combine(outputDir, "metadata.json");
+        var dbPath = Path.Combine(outputDir, "trivy.db");
+
+        if (!File.Exists(metadataPath))
+        {
+            TryDeleteDirectory(builderRoot);
+            throw new InvalidOperationException($"trivy-db metadata not found at '{metadataPath}'.");
+        }
+
+        if (!File.Exists(dbPath))
+        {
+            TryDeleteDirectory(builderRoot);
+            throw new InvalidOperationException($"trivy.db not found at '{dbPath}'.");
+        }
+
+        var archivePath = Path.Combine(builderRoot, "db.tar.gz");
+        await CreateArchiveAsync(archivePath, exportedAt, metadataPath, dbPath, cancellationToken).ConfigureAwait(false);
+
+        var digest = await ComputeDigestAsync(archivePath, cancellationToken).ConfigureAwait(false);
+        var length = new FileInfo(archivePath).Length;
+        var builderMetadata = await File.ReadAllBytesAsync(metadataPath, cancellationToken).ConfigureAwait(false);
+
+        return new TrivyDbBuilderResult(
+            archivePath,
+            digest,
+            length,
+            builderMetadata,
+            builderRoot);
+    }
+
+    private string PrepareBuilderRoot(string exportDirectory, string exportId)
+    {
+        var root = Path.Combine(exportDirectory, $".builder-{exportId}");
+        if (Directory.Exists(root))
+        {
+            Directory.Delete(root, recursive: true);
+        }
+
+        Directory.CreateDirectory(root);
+        return root;
+    }
+
+    private static void TryDeleteDirectory(string directory)
+    {
+        try
+        {
+            if (Directory.Exists(directory))
+            {
+                Directory.Delete(directory, recursive: true);
+            }
+        }
+        catch
+        {
+            // ignore cleanup failures
+        }
+    }
+
+    private async Task RunCliAsync(string cacheDir, string outputDir, CancellationToken cancellationToken)
+    {
+        var builderOptions = _options.Builder ?? new TrivyDbBuilderOptions();
+        var executable = string.IsNullOrWhiteSpace(builderOptions.ExecutablePath)
+            ? "trivy-db"
+            : builderOptions.ExecutablePath;
+
+        var targets = builderOptions.OnlyUpdateTargets ?? new System.Collections.Generic.List<string>();
+        var environment = builderOptions.Environment ?? new System.Collections.Generic.Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = executable,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+        };
+
+        startInfo.ArgumentList.Add("build");
+        startInfo.ArgumentList.Add("--cache-dir");
+        startInfo.ArgumentList.Add(cacheDir);
+        startInfo.ArgumentList.Add("--output-dir");
+        startInfo.ArgumentList.Add(outputDir);
+
+        if (builderOptions.UpdateInterval != default)
+        {
+            startInfo.ArgumentList.Add("--update-interval");
+            startInfo.ArgumentList.Add(ToGoDuration(builderOptions.UpdateInterval));
+        }
+
+        if (targets.Count > 0)
+        {
+            foreach (var target in targets.Where(static t => !string.IsNullOrWhiteSpace(t)))
+            {
+                startInfo.ArgumentList.Add("--only-update");
+                startInfo.ArgumentList.Add(target);
+            }
+        }
+
+        if (!string.IsNullOrWhiteSpace(builderOptions.WorkingDirectory))
+        {
+            startInfo.WorkingDirectory = builderOptions.WorkingDirectory;
+        }
+
+        if (!builderOptions.InheritEnvironment)
+        {
+            startInfo.Environment.Clear();
+        }
+
+        foreach (var kvp in environment)
+        {
+            startInfo.Environment[kvp.Key] = kvp.Value;
+        }
+
+        using var process = new Process { StartInfo = startInfo, EnableRaisingEvents = false };
+
+        var stdOut = new StringBuilder();
+        var stdErr = new StringBuilder();
+
+        var stdoutCompletion = new TaskCompletionSource<object?>();
+        var stderrCompletion = new TaskCompletionSource<object?>();
+
+        process.OutputDataReceived += (_, e) =>
+        {
+            if (e.Data is null)
+            {
+                stdoutCompletion.TrySetResult(null);
+            }
+            else
+            {
+                stdOut.AppendLine(e.Data);
+            }
+        };
+
+        process.ErrorDataReceived += (_, e) =>
+        {
+            if (e.Data is null)
+            {
+                stderrCompletion.TrySetResult(null);
+            }
+            else
+            {
+                stdErr.AppendLine(e.Data);
+            }
+        };
+
+        _logger.LogInformation("Running {Executable} to build Trivy DB", executable);
+
+        try
+        {
+            if (!process.Start())
+            {
+                throw new InvalidOperationException($"Failed to start '{executable}'.");
+            }
+        }
+        catch (Exception ex)
+        {
+            throw new InvalidOperationException($"Failed to start '{executable}'.", ex);
+        }
+
+        process.BeginOutputReadLine();
+        process.BeginErrorReadLine();
+
+        using var registration = cancellationToken.Register(() =>
+        {
+            try
+            {
+                if (!process.HasExited)
+                {
+                    process.Kill(entireProcessTree: true);
+                }
+            }
+            catch
+            {
+                // Ignore kill failures.
+            }
+        });
+
+#if NET8_0_OR_GREATER
+        await process.WaitForExitAsync(cancellationToken).ConfigureAwait(false);
+#else
+        await Task.Run(() => process.WaitForExit(), cancellationToken).ConfigureAwait(false);
+#endif
+
+        await Task.WhenAll(stdoutCompletion.Task, stderrCompletion.Task).ConfigureAwait(false);
+
+        if (process.ExitCode != 0)
+        {
+            _logger.LogError("trivy-db exited with code {ExitCode}. stderr: {Stderr}", process.ExitCode, stdErr.ToString());
+            throw new InvalidOperationException($"'{executable}' exited with code {process.ExitCode}.");
+        }
+
+        if (stdOut.Length > 0)
+        {
+            _logger.LogDebug("trivy-db output: {StdOut}", stdOut.ToString());
+        }
+
+        if (stdErr.Length > 0)
+        {
+            _logger.LogWarning("trivy-db warnings: {StdErr}", stdErr.ToString());
+        }
+    }
+
+    private static async Task CreateArchiveAsync(
+        string archivePath,
+        DateTimeOffset exportedAt,
+        string metadataPath,
+        string dbPath,
+        CancellationToken cancellationToken)
+    {
+        await using var archiveStream = new FileStream(
+            archivePath,
+            FileMode.Create,
+            FileAccess.Write,
+            FileShare.None,
+            bufferSize: 81920,
+            options: FileOptions.Asynchronous | FileOptions.SequentialScan);
+        await using var gzip = new GZipStream(archiveStream, CompressionLevel.SmallestSize, leaveOpen: true);
+        await using var writer = new TarWriter(gzip, TarEntryFormat.Pax, leaveOpen: false);
+
+        var timestamp = exportedAt.UtcDateTime;
+        foreach (var file in EnumerateArchiveEntries(metadataPath, dbPath))
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            var entry = new PaxTarEntry(TarEntryType.RegularFile, file.Name)
+            {
+                ModificationTime = timestamp,
+                Mode = UnixFileMode.UserRead | UnixFileMode.UserWrite | UnixFileMode.GroupRead | UnixFileMode.OtherRead,
+            };
+
+            await using var source = new FileStream(
+                file.Path,
+                FileMode.Open,
+                FileAccess.Read,
+                FileShare.Read,
+                bufferSize: 81920,
+                options: FileOptions.Asynchronous | FileOptions.SequentialScan);
+            entry.DataStream = source;
+            writer.WriteEntry(entry);
+        }
+
+        await writer.DisposeAsync().ConfigureAwait(false);
+        await ZeroGzipMtimeAsync(archivePath, cancellationToken).ConfigureAwait(false);
+    }
+
+    private static IEnumerable<(string Name, string Path)> EnumerateArchiveEntries(string metadataPath, string dbPath)
+    {
+        yield return ("metadata.json", metadataPath);
+        yield return ("trivy.db", dbPath);
+    }
+
+    private static async Task<string> ComputeDigestAsync(string archivePath, CancellationToken cancellationToken)
+    {
+        await using var stream = new FileStream(
+            archivePath,
+            FileMode.Open,
+            FileAccess.Read,
+            FileShare.Read,
+            bufferSize: 81920,
+            options: FileOptions.Asynchronous | FileOptions.SequentialScan);
+        var hash = await SHA256.HashDataAsync(stream, cancellationToken).ConfigureAwait(false);
+        return $"sha256:{Convert.ToHexString(hash).ToLowerInvariant()}";
+    }
+
+    private static async Task ZeroGzipMtimeAsync(string archivePath, CancellationToken cancellationToken)
+    {
+        await using var stream = new FileStream(
+            archivePath,
+            FileMode.Open,
+            FileAccess.ReadWrite,
+            FileShare.None,
+            bufferSize: 8,
+            options: FileOptions.Asynchronous);
+
+        if (stream.Length < 10)
+        {
+            return;
+        }
+
+        stream.Position = 4;
+        var zeros = new byte[4];
+        await stream.WriteAsync(zeros, cancellationToken).ConfigureAwait(false);
+        await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    private static string ToGoDuration(TimeSpan span)
+    {
+        if (span <= TimeSpan.Zero)
+        {
+            return "0s";
+        }
+
+        span = span.Duration();
+        var builder = new StringBuilder();
+
+        var totalHours = (int)span.TotalHours;
+        if (totalHours > 0)
+        {
+            builder.Append(totalHours);
+            builder.Append('h');
+        }
+
+        var minutes = span.Minutes;
+        if (minutes > 0)
+        {
+            builder.Append(minutes);
+            builder.Append('m');
+        }
+
+        var seconds = span.Seconds + span.Milliseconds / 1000.0;
+        if (seconds > 0 || builder.Length == 0)
+        {
+            if (span.Milliseconds == 0)
+            {
+                builder.Append(span.Seconds);
+            }
+            else
+            {
+                builder.Append(seconds.ToString("0.###", CultureInfo.InvariantCulture));
+            }
+            builder.Append('s');
+        }
+
+        return builder.ToString();
+    }
+
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbBuilderResult.cs

@@ -0,0 +1,10 @@
+using System;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record TrivyDbBuilderResult(
+    string ArchivePath,
+    string ArchiveDigest,
+    long ArchiveLength,
+    ReadOnlyMemory<byte> BuilderMetadata,
+    string WorkingDirectory);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbExportJob.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using StellaOps.Feedser.Core.Jobs;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbExportJob : IJob
+{
+    public const string JobKind = "export:trivy-db";
+    public static readonly TimeSpan DefaultTimeout = TimeSpan.FromMinutes(20);
+    public static readonly TimeSpan DefaultLeaseDuration = TimeSpan.FromMinutes(10);
+
+    private readonly TrivyDbFeedExporter _exporter;
+    private readonly ILogger<TrivyDbExportJob> _logger;
+
+    public TrivyDbExportJob(TrivyDbFeedExporter exporter, ILogger<TrivyDbExportJob> logger)
+    {
+        _exporter = exporter ?? throw new ArgumentNullException(nameof(exporter));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task ExecuteAsync(JobExecutionContext context, CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Executing Trivy DB export job {RunId}", context.RunId);
+        await _exporter.ExportAsync(context.Services, cancellationToken).ConfigureAwait(false);
+        _logger.LogInformation("Completed Trivy DB export job {RunId}", context.RunId);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbExportMode.cs

@@ -0,0 +1,8 @@
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public enum TrivyDbExportMode
+{
+    Full,
+    Delta,
+    Skip,
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbExportOptions.cs

@@ -0,0 +1,80 @@
+using System;
+using System.IO;
+using System.Collections.Generic;
+using StellaOps.Feedser.Exporter.Json;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbExportOptions
+{
+    public string OutputRoot { get; set; } = Path.Combine("exports", "trivy");
+
+    public string ReferencePrefix { get; set; } = "feedser/trivy";
+
+    public string TagFormat { get; set; } = "yyyyMMdd'T'HHmmss'Z'";
+
+    public string DatabaseVersionFormat { get; set; } = "yyyyMMdd'T'HHmmss'Z'";
+
+    public bool KeepWorkingTree { get; set; }
+
+    public string? TargetRepository { get; set; }
+
+    public JsonExportOptions Json { get; set; } = new()
+    {
+        OutputRoot = Path.Combine("exports", "trivy", "tree")
+    };
+
+    public TrivyDbBuilderOptions Builder { get; set; } = new();
+
+    public TrivyDbOrasOptions Oras { get; set; } = new();
+
+    public TrivyDbOfflineBundleOptions OfflineBundle { get; set; } = new();
+
+    public string GetExportRoot(string exportId)
+    {
+        ArgumentException.ThrowIfNullOrEmpty(exportId);
+        var root = Path.GetFullPath(OutputRoot);
+        return Path.Combine(root, exportId);
+    }
+}
+
+public sealed class TrivyDbBuilderOptions
+{
+    public string ExecutablePath { get; set; } = "trivy-db";
+
+    public string? WorkingDirectory { get; set; }
+
+    public TimeSpan UpdateInterval { get; set; } = TimeSpan.FromHours(24);
+
+    public List<string> OnlyUpdateTargets { get; set; } = new();
+
+    public Dictionary<string, string> Environment { get; set; } = new(StringComparer.OrdinalIgnoreCase);
+
+    public bool InheritEnvironment { get; set; } = true;
+}
+
+public sealed class TrivyDbOrasOptions
+{
+    public bool Enabled { get; set; }
+
+    public string ExecutablePath { get; set; } = "oras";
+
+    public string? WorkingDirectory { get; set; }
+
+    public bool InheritEnvironment { get; set; } = true;
+
+    public List<string> AdditionalArguments { get; set; } = new();
+
+    public Dictionary<string, string> Environment { get; set; } = new(StringComparer.OrdinalIgnoreCase);
+
+    public bool SkipTlsVerify { get; set; }
+
+    public bool UseHttp { get; set; }
+}
+
+public sealed class TrivyDbOfflineBundleOptions
+{
+    public bool Enabled { get; set; }
+
+    public string? FileName { get; set; }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbExportPlan.cs

@@ -0,0 +1,7 @@
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record TrivyDbExportPlan(
+    TrivyDbExportMode Mode,
+    string TreeDigest,
+    string? BaseExportId,
+    string? BaseManifestDigest);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbExportPlanner.cs

@@ -0,0 +1,33 @@
+using System;
+using StellaOps.Feedser.Storage.Mongo.Exporting;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbExportPlanner
+{
+    public TrivyDbExportPlan CreatePlan(ExportStateRecord? existingState, string treeDigest)
+    {
+        ArgumentException.ThrowIfNullOrEmpty(treeDigest);
+
+        if (existingState is null)
+        {
+            return new TrivyDbExportPlan(TrivyDbExportMode.Full, treeDigest, BaseExportId: null, BaseManifestDigest: null);
+        }
+
+        if (string.Equals(existingState.ExportCursor, treeDigest, StringComparison.Ordinal))
+        {
+            return new TrivyDbExportPlan(
+                TrivyDbExportMode.Skip,
+                treeDigest,
+                existingState.BaseExportId,
+                existingState.LastFullDigest);
+        }
+
+        // Placeholder for future delta support – current behavior always rebuilds when tree changes.
+        return new TrivyDbExportPlan(
+            TrivyDbExportMode.Full,
+            treeDigest,
+            existingState.BaseExportId,
+            existingState.LastFullDigest);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbExporterDependencyInjectionRoutine.cs

@@ -0,0 +1,64 @@
+using System;
+using System.IO;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
+using StellaOps.DependencyInjection;
+using StellaOps.Feedser.Core.Jobs;
+using StellaOps.Feedser.Exporter.Json;
+using StellaOps.Feedser.Storage.Mongo.Exporting;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbExporterDependencyInjectionRoutine : IDependencyInjectionRoutine
+{
+    private const string ConfigurationSection = "feedser:exporters:trivyDb";
+
+    public IServiceCollection Register(IServiceCollection services, IConfiguration configuration)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(configuration);
+
+        services.TryAddSingleton<IJsonExportPathResolver, VulnListJsonExportPathResolver>();
+        services.TryAddSingleton<ExportStateManager>();
+
+        services.AddOptions<TrivyDbExportOptions>()
+            .Bind(configuration.GetSection(ConfigurationSection))
+            .PostConfigure(static options =>
+            {
+                options.OutputRoot = Normalize(options.OutputRoot, Path.Combine("exports", "trivy"));
+                options.Json.OutputRoot = Normalize(options.Json.OutputRoot, Path.Combine("exports", "trivy", "tree"));
+                options.TagFormat = string.IsNullOrWhiteSpace(options.TagFormat) ? "yyyyMMdd'T'HHmmss'Z'" : options.TagFormat;
+                options.DatabaseVersionFormat = string.IsNullOrWhiteSpace(options.DatabaseVersionFormat) ? "yyyyMMdd'T'HHmmss'Z'" : options.DatabaseVersionFormat;
+                options.ReferencePrefix = string.IsNullOrWhiteSpace(options.ReferencePrefix) ? "feedser/trivy" : options.ReferencePrefix;
+            });
+
+        services.AddSingleton<TrivyDbPackageBuilder>();
+        services.AddSingleton<TrivyDbOciWriter>();
+        services.AddSingleton<TrivyDbExportPlanner>();
+        services.AddSingleton<ITrivyDbBuilder, TrivyDbBoltBuilder>();
+        services.AddSingleton<ITrivyDbOrasPusher, TrivyDbOrasPusher>();
+        services.AddSingleton<TrivyDbFeedExporter>();
+        services.AddTransient<TrivyDbExportJob>();
+
+        services.PostConfigure<JobSchedulerOptions>(options =>
+        {
+            if (!options.Definitions.ContainsKey(TrivyDbExportJob.JobKind))
+            {
+                options.Definitions[TrivyDbExportJob.JobKind] = new JobDefinition(
+                    TrivyDbExportJob.JobKind,
+                    typeof(TrivyDbExportJob),
+                    TrivyDbExportJob.DefaultTimeout,
+                    TrivyDbExportJob.DefaultLeaseDuration,
+                    null,
+                    true);
+            }
+        });
+
+        return services;
+    }
+
+    private static string Normalize(string? value, string fallback)
+        => string.IsNullOrWhiteSpace(value) ? fallback : value;
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbExporterPlugin.cs

@@ -0,0 +1,23 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using StellaOps.Feedser.Storage.Mongo.Advisories;
+using StellaOps.Plugin;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbExporterPlugin : IExporterPlugin
+{
+    public string Name => TrivyDbFeedExporter.ExporterName;
+
+    public bool IsAvailable(IServiceProvider services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        return services.GetService<IAdvisoryStore>() is not null;
+    }
+
+    public IFeedExporter Create(IServiceProvider services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        return ActivatorUtilities.CreateInstance<TrivyDbFeedExporter>(services);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbFeedExporter.cs

@@ -0,0 +1,365 @@
+using System;
+using System.Globalization;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Formats.Tar;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using StellaOps.Feedser.Exporter.Json;
+using StellaOps.Feedser.Storage.Mongo.Advisories;
+using StellaOps.Feedser.Storage.Mongo.Exporting;
+using StellaOps.Plugin;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbFeedExporter : IFeedExporter
+{
+    public const string ExporterName = "trivy-db";
+    public const string ExporterId = "export:trivy-db";
+
+    private readonly IAdvisoryStore _advisoryStore;
+    private readonly IJsonExportPathResolver _pathResolver;
+    private readonly TrivyDbExportOptions _options;
+    private readonly TrivyDbPackageBuilder _packageBuilder;
+    private readonly TrivyDbOciWriter _ociWriter;
+    private readonly ExportStateManager _stateManager;
+    private readonly TrivyDbExportPlanner _exportPlanner;
+    private readonly ITrivyDbBuilder _builder;
+    private readonly ITrivyDbOrasPusher _orasPusher;
+    private readonly ILogger<TrivyDbFeedExporter> _logger;
+    private readonly TimeProvider _timeProvider;
+    private readonly string _exporterVersion;
+
+    public TrivyDbFeedExporter(
+        IAdvisoryStore advisoryStore,
+        IJsonExportPathResolver pathResolver,
+        IOptions<TrivyDbExportOptions> options,
+        TrivyDbPackageBuilder packageBuilder,
+        TrivyDbOciWriter ociWriter,
+        ExportStateManager stateManager,
+        TrivyDbExportPlanner exportPlanner,
+        ITrivyDbBuilder builder,
+        ITrivyDbOrasPusher orasPusher,
+        ILogger<TrivyDbFeedExporter> logger,
+        TimeProvider? timeProvider = null)
+    {
+        _advisoryStore = advisoryStore ?? throw new ArgumentNullException(nameof(advisoryStore));
+        _pathResolver = pathResolver ?? throw new ArgumentNullException(nameof(pathResolver));
+        _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+        _packageBuilder = packageBuilder ?? throw new ArgumentNullException(nameof(packageBuilder));
+        _ociWriter = ociWriter ?? throw new ArgumentNullException(nameof(ociWriter));
+        _stateManager = stateManager ?? throw new ArgumentNullException(nameof(stateManager));
+        _exportPlanner = exportPlanner ?? throw new ArgumentNullException(nameof(exportPlanner));
+        _builder = builder ?? throw new ArgumentNullException(nameof(builder));
+        _orasPusher = orasPusher ?? throw new ArgumentNullException(nameof(orasPusher));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        _timeProvider = timeProvider ?? TimeProvider.System;
+        _exporterVersion = ExporterVersion.GetVersion(typeof(TrivyDbFeedExporter));
+    }
+
+    public string Name => ExporterName;
+
+    public async Task ExportAsync(IServiceProvider services, CancellationToken cancellationToken)
+    {
+        var exportedAt = _timeProvider.GetUtcNow();
+        var exportId = exportedAt.ToString(_options.TagFormat, CultureInfo.InvariantCulture);
+        var reference = $"{_options.ReferencePrefix}:{exportId}";
+
+        _logger.LogInformation("Starting Trivy DB export {ExportId}", exportId);
+
+        var jsonBuilder = new JsonExportSnapshotBuilder(_options.Json, _pathResolver);
+        var advisoryStream = _advisoryStore.StreamAsync(cancellationToken);
+        var jsonResult = await jsonBuilder.WriteAsync(advisoryStream, exportedAt, exportId, cancellationToken).ConfigureAwait(false);
+
+        _logger.LogInformation(
+            "Prepared Trivy JSON tree {ExportId} with {AdvisoryCount} advisories ({Bytes} bytes)",
+            exportId,
+            jsonResult.AdvisoryCount,
+            jsonResult.TotalBytes);
+
+        var treeDigest = ExportDigestCalculator.ComputeTreeDigest(jsonResult);
+        var existingState = await _stateManager.GetAsync(ExporterId, cancellationToken).ConfigureAwait(false);
+        var plan = _exportPlanner.CreatePlan(existingState, treeDigest);
+
+        if (plan.Mode == TrivyDbExportMode.Skip)
+        {
+            _logger.LogInformation(
+                "Trivy DB export {ExportId} unchanged from base {BaseExport}; skipping OCI packaging.",
+                exportId,
+                plan.BaseExportId ?? "(none)");
+
+            if (!_options.KeepWorkingTree)
+            {
+                TryDeleteDirectory(jsonResult.ExportDirectory);
+            }
+
+            return;
+        }
+
+        var builderResult = await _builder.BuildAsync(jsonResult, exportedAt, exportId, cancellationToken).ConfigureAwait(false);
+        var metadataBytes = CreateMetadataJson(builderResult.BuilderMetadata, treeDigest, jsonResult, exportedAt);
+
+        try
+        {
+            var package = _packageBuilder.BuildPackage(new TrivyDbPackageRequest(
+                metadataBytes,
+                builderResult.ArchivePath,
+                builderResult.ArchiveDigest,
+                builderResult.ArchiveLength,
+                exportedAt,
+                exportedAt.ToString(_options.DatabaseVersionFormat, CultureInfo.InvariantCulture)));
+
+            var destination = _options.GetExportRoot(exportId);
+            var ociResult = await _ociWriter.WriteAsync(package, destination, reference, cancellationToken).ConfigureAwait(false);
+
+            if (_options.Oras.Enabled)
+            {
+                await _orasPusher.PushAsync(destination, reference, exportId, cancellationToken).ConfigureAwait(false);
+            }
+
+            _logger.LogInformation(
+                "Trivy DB export {ExportId} wrote manifest {ManifestDigest}",
+                exportId,
+                ociResult.ManifestDigest);
+
+            await _stateManager.StoreFullExportAsync(
+                ExporterId,
+                exportId,
+                ociResult.ManifestDigest,
+                cursor: treeDigest,
+                targetRepository: _options.TargetRepository,
+                exporterVersion: _exporterVersion,
+                cancellationToken: cancellationToken).ConfigureAwait(false);
+
+            await CreateOfflineBundleAsync(destination, exportId, exportedAt, cancellationToken).ConfigureAwait(false);
+        }
+        finally
+        {
+            TryDeleteDirectory(builderResult.WorkingDirectory);
+        }
+
+        if (!_options.KeepWorkingTree)
+        {
+            TryDeleteDirectory(jsonResult.ExportDirectory);
+        }
+    }
+
+    private byte[] CreateMetadataJson(
+        ReadOnlyMemory<byte> builderMetadata,
+        string treeDigest,
+        JsonExportResult result,
+        DateTimeOffset exportedAt)
+    {
+        var metadata = new TrivyMetadata
+        {
+            GeneratedAt = exportedAt.UtcDateTime,
+            AdvisoryCount = result.AdvisoryCount,
+            TreeDigest = treeDigest,
+            TreeBytes = result.TotalBytes,
+            ExporterVersion = _exporterVersion,
+            Builder = ParseBuilderMetadata(builderMetadata.Span),
+        };
+
+        return JsonSerializer.SerializeToUtf8Bytes(metadata, new JsonSerializerOptions
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+            WriteIndented = false,
+        });
+    }
+
+    private static BuilderMetadata? ParseBuilderMetadata(ReadOnlySpan<byte> payload)
+    {
+        if (payload.IsEmpty)
+        {
+            return null;
+        }
+
+        try
+        {
+            return JsonSerializer.Deserialize<BuilderMetadata>(payload, new JsonSerializerOptions
+            {
+                PropertyNameCaseInsensitive = true,
+            });
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    private async Task CreateOfflineBundleAsync(string layoutPath, string exportId, DateTimeOffset exportedAt, CancellationToken cancellationToken)
+    {
+        if (!_options.OfflineBundle.Enabled)
+        {
+            return;
+        }
+
+        var parent = Path.GetDirectoryName(layoutPath) ?? layoutPath;
+        var fileName = string.IsNullOrWhiteSpace(_options.OfflineBundle.FileName)
+            ? $"{exportId}.offline.tar.gz"
+            : _options.OfflineBundle.FileName.Replace("{exportId}", exportId, StringComparison.Ordinal);
+
+        var bundlePath = Path.IsPathRooted(fileName) ? fileName : Path.Combine(parent, fileName);
+        Directory.CreateDirectory(Path.GetDirectoryName(bundlePath)!);
+
+        if (File.Exists(bundlePath))
+        {
+            File.Delete(bundlePath);
+        }
+
+        var normalizedRoot = Path.GetFullPath(layoutPath);
+        var directories = Directory.GetDirectories(normalizedRoot, "*", SearchOption.AllDirectories)
+            .Select(dir => NormalizeTarPath(normalizedRoot, dir) + "/")
+            .OrderBy(static path => path, StringComparer.Ordinal)
+            .ToArray();
+
+        var files = Directory.GetFiles(normalizedRoot, "*", SearchOption.AllDirectories)
+            .Select(file => NormalizeTarPath(normalizedRoot, file))
+            .OrderBy(static path => path, StringComparer.Ordinal)
+            .ToArray();
+
+        await using (var archiveStream = new FileStream(
+            bundlePath,
+            FileMode.Create,
+            FileAccess.Write,
+            FileShare.None,
+            bufferSize: 81920,
+            options: FileOptions.Asynchronous | FileOptions.SequentialScan))
+        await using (var gzip = new GZipStream(archiveStream, CompressionLevel.SmallestSize, leaveOpen: true))
+        await using (var writer = new TarWriter(gzip, TarEntryFormat.Pax, leaveOpen: false))
+        {
+            var timestamp = exportedAt.UtcDateTime;
+
+            foreach (var directory in directories)
+            {
+                var entry = new PaxTarEntry(TarEntryType.Directory, directory)
+                {
+                    ModificationTime = timestamp,
+                    Mode = UnixFileMode.UserRead | UnixFileMode.UserWrite | UnixFileMode.UserExecute |
+                           UnixFileMode.GroupRead | UnixFileMode.GroupExecute |
+                           UnixFileMode.OtherRead | UnixFileMode.OtherExecute,
+                };
+
+                writer.WriteEntry(entry);
+            }
+
+            foreach (var relativePath in files)
+            {
+                var fullPath = Path.Combine(normalizedRoot, relativePath.Replace('/', Path.DirectorySeparatorChar));
+                var entry = new PaxTarEntry(TarEntryType.RegularFile, relativePath)
+                {
+                    ModificationTime = timestamp,
+                    Mode = UnixFileMode.UserRead | UnixFileMode.UserWrite |
+                           UnixFileMode.GroupRead |
+                           UnixFileMode.OtherRead,
+                };
+
+                await using var source = new FileStream(
+                    fullPath,
+                    FileMode.Open,
+                    FileAccess.Read,
+                    FileShare.Read,
+                    bufferSize: 81920,
+                    options: FileOptions.Asynchronous | FileOptions.SequentialScan);
+                entry.DataStream = source;
+                writer.WriteEntry(entry);
+            }
+        }
+
+        await ZeroGzipMtimeAsync(bundlePath, cancellationToken).ConfigureAwait(false);
+
+        var digest = await ComputeSha256Async(bundlePath, cancellationToken).ConfigureAwait(false);
+        var length = new FileInfo(bundlePath).Length;
+        _logger.LogInformation("Wrote offline bundle {BundlePath} ({Length} bytes, digest {Digest})", bundlePath, length, digest);
+    }
+
+    private static void TryDeleteDirectory(string directory)
+    {
+        try
+        {
+            if (Directory.Exists(directory))
+            {
+                Directory.Delete(directory, recursive: true);
+            }
+        }
+        catch
+        {
+            // Best effort cleanup – ignore failures.
+        }
+    }
+
+    private static async Task ZeroGzipMtimeAsync(string archivePath, CancellationToken cancellationToken)
+    {
+        await using var stream = new FileStream(
+            archivePath,
+            FileMode.Open,
+            FileAccess.ReadWrite,
+            FileShare.None,
+            bufferSize: 8,
+            options: FileOptions.Asynchronous);
+
+        if (stream.Length < 10)
+        {
+            return;
+        }
+
+        stream.Position = 4;
+        var zeros = new byte[4];
+        await stream.WriteAsync(zeros, cancellationToken).ConfigureAwait(false);
+        await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    private static async Task<string> ComputeSha256Async(string path, CancellationToken cancellationToken)
+    {
+        await using var stream = new FileStream(
+            path,
+            FileMode.Open,
+            FileAccess.Read,
+            FileShare.Read,
+            bufferSize: 81920,
+            options: FileOptions.Asynchronous | FileOptions.SequentialScan);
+        var hash = await SHA256.HashDataAsync(stream, cancellationToken).ConfigureAwait(false);
+        return $"sha256:{Convert.ToHexString(hash).ToLowerInvariant()}";
+    }
+
+    private static string NormalizeTarPath(string root, string fullPath)
+    {
+        var relative = Path.GetRelativePath(root, fullPath);
+        var normalized = relative.Replace(Path.DirectorySeparatorChar, '/');
+        return string.IsNullOrEmpty(normalized) ? "." : normalized;
+    }
+
+    private sealed class TrivyMetadata
+    {
+        public DateTime GeneratedAt { get; set; }
+
+        public int AdvisoryCount { get; set; }
+
+        public string TreeDigest { get; set; } = string.Empty;
+
+        public long TreeBytes { get; set; }
+
+        public string ExporterVersion { get; set; } = string.Empty;
+
+        public BuilderMetadata? Builder { get; set; }
+    }
+
+    private sealed class BuilderMetadata
+    {
+        [JsonPropertyName("Version")]
+        public int Version { get; set; }
+
+        public DateTime NextUpdate { get; set; }
+
+        public DateTime UpdatedAt { get; set; }
+
+        public DateTime? DownloadedAt { get; set; }
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbMediaTypes.cs

@@ -0,0 +1,9 @@
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public static class TrivyDbMediaTypes
+{
+    public const string OciManifest = "application/vnd.oci.image.manifest.v1+json";
+    public const string OciImageIndex = "application/vnd.oci.image.index.v1+json";
+    public const string TrivyConfig = "application/vnd.aquasec.trivy.config.v1+json";
+    public const string TrivyLayer = "application/vnd.aquasec.trivy.db.layer.v1.tar+gzip";
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbOciWriteResult.cs

@@ -0,0 +1,8 @@
+using System.Collections.Generic;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record TrivyDbOciWriteResult(
+    string RootDirectory,
+    string ManifestDigest,
+    IReadOnlyCollection<string> BlobDigests);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbOciWriter.cs

@@ -0,0 +1,172 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+/// <summary>
+/// Writes a Trivy DB package to an OCI image layout directory with deterministic content.
+/// </summary>
+public sealed class TrivyDbOciWriter
+{
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull,
+        WriteIndented = false,
+    };
+
+    private static readonly byte[] OciLayoutBytes = Encoding.UTF8.GetBytes("{\"imageLayoutVersion\":\"1.0.0\"}");
+
+    public async Task<TrivyDbOciWriteResult> WriteAsync(
+        TrivyDbPackage package,
+        string destination,
+        string reference,
+        CancellationToken cancellationToken)
+    {
+        if (package is null)
+        {
+            throw new ArgumentNullException(nameof(package));
+        }
+
+        if (string.IsNullOrWhiteSpace(destination))
+        {
+            throw new ArgumentException("Destination directory must be provided.", nameof(destination));
+        }
+
+        if (string.IsNullOrWhiteSpace(reference))
+        {
+            throw new ArgumentException("Reference tag must be provided.", nameof(reference));
+        }
+
+        var root = Path.GetFullPath(destination);
+        if (Directory.Exists(root))
+        {
+            Directory.Delete(root, recursive: true);
+        }
+
+        Directory.CreateDirectory(root);
+        var timestamp = package.Config.GeneratedAt.UtcDateTime;
+
+        await WriteFileAsync(Path.Combine(root, "metadata.json"), package.MetadataJson.ToArray(), timestamp, cancellationToken).ConfigureAwait(false);
+        await WriteFileAsync(Path.Combine(root, "oci-layout"), OciLayoutBytes, timestamp, cancellationToken).ConfigureAwait(false);
+
+        var blobsRoot = Path.Combine(root, "blobs", "sha256");
+        Directory.CreateDirectory(blobsRoot);
+        Directory.SetLastWriteTimeUtc(Path.GetDirectoryName(blobsRoot)!, timestamp);
+        Directory.SetLastWriteTimeUtc(blobsRoot, timestamp);
+
+        var writtenDigests = new HashSet<string>(StringComparer.Ordinal);
+        foreach (var pair in package.Blobs)
+        {
+            if (writtenDigests.Add(pair.Key))
+            {
+                await WriteBlobAsync(blobsRoot, pair.Key, pair.Value, timestamp, cancellationToken).ConfigureAwait(false);
+            }
+        }
+
+        var manifestBytes = JsonSerializer.SerializeToUtf8Bytes(package.Manifest, SerializerOptions);
+        var manifestDigest = ComputeDigest(manifestBytes);
+        if (writtenDigests.Add(manifestDigest))
+        {
+            await WriteBlobAsync(blobsRoot, manifestDigest, TrivyDbBlob.FromBytes(manifestBytes), timestamp, cancellationToken).ConfigureAwait(false);
+        }
+
+        var manifestDescriptor = new OciDescriptor(
+            TrivyDbMediaTypes.OciManifest,
+            manifestDigest,
+            manifestBytes.LongLength,
+            new Dictionary<string, string>
+            {
+                ["org.opencontainers.image.ref.name"] = reference,
+            });
+        var index = new OciIndex(2, new[] { manifestDescriptor });
+        var indexBytes = JsonSerializer.SerializeToUtf8Bytes(index, SerializerOptions);
+        await WriteFileAsync(Path.Combine(root, "index.json"), indexBytes, timestamp, cancellationToken).ConfigureAwait(false);
+
+        Directory.SetLastWriteTimeUtc(root, timestamp);
+
+        var blobDigests = writtenDigests.ToArray();
+        Array.Sort(blobDigests, StringComparer.Ordinal);
+        return new TrivyDbOciWriteResult(root, manifestDigest, blobDigests);
+    }
+
+    private static async Task WriteFileAsync(string path, byte[] bytes, DateTime utcTimestamp, CancellationToken cancellationToken)
+    {
+        var directory = Path.GetDirectoryName(path);
+        if (!string.IsNullOrEmpty(directory))
+        {
+            Directory.CreateDirectory(directory);
+            Directory.SetLastWriteTimeUtc(directory, utcTimestamp);
+        }
+
+        await File.WriteAllBytesAsync(path, bytes, cancellationToken).ConfigureAwait(false);
+        File.SetLastWriteTimeUtc(path, utcTimestamp);
+    }
+
+    private static async Task WriteBlobAsync(string blobsRoot, string digest, TrivyDbBlob blob, DateTime utcTimestamp, CancellationToken cancellationToken)
+    {
+        var fileName = ResolveDigestFileName(digest);
+        var path = Path.Combine(blobsRoot, fileName);
+        var directory = Path.GetDirectoryName(path);
+        if (!string.IsNullOrEmpty(directory))
+        {
+            Directory.CreateDirectory(directory);
+            Directory.SetLastWriteTimeUtc(directory, utcTimestamp);
+        }
+
+        await using var source = await blob.OpenReadAsync(cancellationToken).ConfigureAwait(false);
+        await using var destination = new FileStream(
+            path,
+            FileMode.Create,
+            FileAccess.Write,
+            FileShare.None,
+            bufferSize: 81920,
+            options: FileOptions.Asynchronous | FileOptions.SequentialScan);
+
+        await source.CopyToAsync(destination, cancellationToken).ConfigureAwait(false);
+        await destination.FlushAsync(cancellationToken).ConfigureAwait(false);
+        File.SetLastWriteTimeUtc(path, utcTimestamp);
+    }
+
+    private static string ResolveDigestFileName(string digest)
+    {
+        if (!digest.StartsWith("sha256:", StringComparison.Ordinal))
+        {
+            throw new InvalidOperationException($"Only sha256 digests are supported. Received '{digest}'.");
+        }
+
+        var hex = digest[7..];
+        if (hex.Length == 0)
+        {
+            throw new InvalidOperationException("Digest hex component cannot be empty.");
+        }
+
+        return hex;
+    }
+
+    private static string ComputeDigest(ReadOnlySpan<byte> payload)
+    {
+        var hash = System.Security.Cryptography.SHA256.HashData(payload);
+        var hex = Convert.ToHexString(hash);
+        Span<char> buffer = stackalloc char[7 + hex.Length]; // "sha256:" + hex
+        buffer[0] = 's';
+        buffer[1] = 'h';
+        buffer[2] = 'a';
+        buffer[3] = '2';
+        buffer[4] = '5';
+        buffer[5] = '6';
+        buffer[6] = ':';
+        for (var i = 0; i < hex.Length; i++)
+        {
+            buffer[7 + i] = char.ToLowerInvariant(hex[i]);
+        }
+
+        return new string(buffer);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbOrasPusher.cs

@@ -0,0 +1,209 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbOrasPusher : ITrivyDbOrasPusher
+{
+    private readonly TrivyDbExportOptions _options;
+    private readonly ILogger<TrivyDbOrasPusher> _logger;
+
+    public TrivyDbOrasPusher(IOptions<TrivyDbExportOptions> options, ILogger<TrivyDbOrasPusher> logger)
+    {
+        _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task PushAsync(string layoutPath, string reference, string exportId, CancellationToken cancellationToken)
+    {
+        var orasOptions = _options.Oras;
+        if (!orasOptions.Enabled)
+        {
+            return;
+        }
+
+        if (string.IsNullOrWhiteSpace(reference))
+        {
+            throw new InvalidOperationException("ORAS push requested but reference is empty.");
+        }
+
+        if (!Directory.Exists(layoutPath))
+        {
+            throw new DirectoryNotFoundException($"OCI layout directory '{layoutPath}' does not exist.");
+        }
+
+        var executable = string.IsNullOrWhiteSpace(orasOptions.ExecutablePath) ? "oras" : orasOptions.ExecutablePath;
+        var tag = ResolveTag(reference, exportId);
+        var layoutReference = $"{layoutPath}:{tag}";
+
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = executable,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+        };
+
+        startInfo.ArgumentList.Add("cp");
+        startInfo.ArgumentList.Add("--from-oci-layout");
+        startInfo.ArgumentList.Add(layoutReference);
+        if (orasOptions.SkipTlsVerify)
+        {
+            startInfo.ArgumentList.Add("--insecure");
+        }
+        if (orasOptions.UseHttp)
+        {
+            startInfo.ArgumentList.Add("--plain-http");
+        }
+
+        if (orasOptions.AdditionalArguments is { Count: > 0 })
+        {
+            foreach (var arg in orasOptions.AdditionalArguments)
+            {
+                if (!string.IsNullOrWhiteSpace(arg))
+                {
+                    startInfo.ArgumentList.Add(arg);
+                }
+            }
+        }
+
+        startInfo.ArgumentList.Add(reference);
+
+        if (!string.IsNullOrWhiteSpace(orasOptions.WorkingDirectory))
+        {
+            startInfo.WorkingDirectory = orasOptions.WorkingDirectory;
+        }
+
+        if (!orasOptions.InheritEnvironment)
+        {
+            startInfo.Environment.Clear();
+        }
+
+        if (orasOptions.Environment is { Count: > 0 })
+        {
+            foreach (var kvp in orasOptions.Environment)
+            {
+                if (!string.IsNullOrEmpty(kvp.Key))
+                {
+                    startInfo.Environment[kvp.Key] = kvp.Value;
+                }
+            }
+        }
+
+        using var process = new Process { StartInfo = startInfo };
+        var stdout = new StringBuilder();
+        var stderr = new StringBuilder();
+        var stdoutCompletion = new TaskCompletionSource<object?>();
+        var stderrCompletion = new TaskCompletionSource<object?>();
+
+        process.OutputDataReceived += (_, e) =>
+        {
+            if (e.Data is null)
+            {
+                stdoutCompletion.TrySetResult(null);
+            }
+            else
+            {
+                stdout.AppendLine(e.Data);
+            }
+        };
+
+        process.ErrorDataReceived += (_, e) =>
+        {
+            if (e.Data is null)
+            {
+                stderrCompletion.TrySetResult(null);
+            }
+            else
+            {
+                stderr.AppendLine(e.Data);
+            }
+        };
+
+        _logger.LogInformation("Pushing Trivy DB export {ExportId} to {Reference} using {Executable}", exportId, reference, executable);
+
+        try
+        {
+            if (!process.Start())
+            {
+                throw new InvalidOperationException($"Failed to start '{executable}'.");
+            }
+        }
+        catch (Exception ex)
+        {
+            throw new InvalidOperationException($"Failed to start '{executable}'.", ex);
+        }
+
+        process.BeginOutputReadLine();
+        process.BeginErrorReadLine();
+
+        using var registration = cancellationToken.Register(() =>
+        {
+            try
+            {
+                if (!process.HasExited)
+                {
+                    process.Kill(entireProcessTree: true);
+                }
+            }
+            catch
+            {
+                // ignore
+            }
+        });
+
+#if NET8_0_OR_GREATER
+        await process.WaitForExitAsync(cancellationToken).ConfigureAwait(false);
+#else
+        await Task.Run(() => process.WaitForExit(), cancellationToken).ConfigureAwait(false);
+#endif
+
+        await Task.WhenAll(stdoutCompletion.Task, stderrCompletion.Task).ConfigureAwait(false);
+
+        if (process.ExitCode != 0)
+        {
+            _logger.LogError("ORAS push for {Reference} failed with code {Code}. stderr: {Stderr}", reference, process.ExitCode, stderr.ToString());
+            throw new InvalidOperationException($"'{executable}' exited with code {process.ExitCode}.");
+        }
+
+        if (stdout.Length > 0)
+        {
+            _logger.LogDebug("ORAS push output: {Stdout}", stdout.ToString());
+        }
+
+        if (stderr.Length > 0)
+        {
+            _logger.LogWarning("ORAS push warnings: {Stderr}", stderr.ToString());
+        }
+    }
+
+    private static string ResolveTag(string reference, string fallback)
+    {
+        if (string.IsNullOrWhiteSpace(reference))
+        {
+            return fallback;
+        }
+
+        var atIndex = reference.IndexOf('@');
+        if (atIndex >= 0)
+        {
+            reference = reference[..atIndex];
+        }
+
+        var slashIndex = reference.LastIndexOf('/');
+        var colonIndex = reference.LastIndexOf(':');
+        if (colonIndex > slashIndex && colonIndex >= 0)
+        {
+            return reference[(colonIndex + 1)..];
+        }
+
+        return fallback;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbPackage.cs

@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record TrivyDbPackage(
+    OciManifest Manifest,
+    TrivyConfigDocument Config,
+    IReadOnlyDictionary<string, TrivyDbBlob> Blobs,
+    ReadOnlyMemory<byte> MetadataJson);

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbPackageBuilder.cs

@@ -0,0 +1,116 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.IO;
+using System.Security.Cryptography;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed class TrivyDbPackageBuilder
+{
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        WriteIndented = false,
+    };
+
+    public TrivyDbPackage BuildPackage(TrivyDbPackageRequest request)
+    {
+        if (request is null)
+        {
+            throw new ArgumentNullException(nameof(request));
+        }
+
+        if (request.MetadataJson.IsEmpty)
+        {
+            throw new ArgumentException("Metadata JSON payload must be provided.", nameof(request));
+        }
+
+        if (string.IsNullOrWhiteSpace(request.DatabaseArchivePath))
+        {
+            throw new ArgumentException("Database archive path must be provided.", nameof(request));
+        }
+
+        if (!File.Exists(request.DatabaseArchivePath))
+        {
+            throw new FileNotFoundException("Database archive path not found.", request.DatabaseArchivePath);
+        }
+
+        if (string.IsNullOrWhiteSpace(request.DatabaseDigest))
+        {
+            throw new ArgumentException("Database archive digest must be provided.", nameof(request));
+        }
+
+        if (request.DatabaseLength < 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(request.DatabaseLength));
+        }
+
+        var metadataBytes = request.MetadataJson;
+        var generatedAt = request.GeneratedAt.ToUniversalTime();
+        var configDocument = new TrivyConfigDocument(
+            TrivyDbMediaTypes.TrivyConfig,
+            generatedAt,
+            request.DatabaseVersion,
+            request.DatabaseDigest,
+            request.DatabaseLength);
+
+        var configBytes = JsonSerializer.SerializeToUtf8Bytes(configDocument, SerializerOptions);
+        var configDigest = ComputeDigest(configBytes);
+
+        var configDescriptor = new OciDescriptor(
+            TrivyDbMediaTypes.TrivyConfig,
+            configDigest,
+            configBytes.LongLength,
+            new Dictionary<string, string>
+            {
+                ["org.opencontainers.image.title"] = "config.json",
+            });
+
+        var layerDescriptor = new OciDescriptor(
+            TrivyDbMediaTypes.TrivyLayer,
+            request.DatabaseDigest,
+            request.DatabaseLength,
+            new Dictionary<string, string>
+            {
+                ["org.opencontainers.image.title"] = "db.tar.gz",
+            });
+
+        var manifest = new OciManifest(
+            2,
+            TrivyDbMediaTypes.OciManifest,
+            configDescriptor,
+            ImmutableArray.Create(layerDescriptor));
+
+        var blobs = new Dictionary<string, TrivyDbBlob>(StringComparer.Ordinal)
+        {
+            [configDigest] = TrivyDbBlob.FromBytes(configBytes),
+            [request.DatabaseDigest] = TrivyDbBlob.FromFile(request.DatabaseArchivePath, request.DatabaseLength),
+        };
+
+        return new TrivyDbPackage(manifest, configDocument, blobs, metadataBytes);
+    }
+
+    private static string ComputeDigest(ReadOnlySpan<byte> payload)
+    {
+        var hash = SHA256.HashData(payload);
+        var hex = Convert.ToHexString(hash);
+        Span<char> buffer = stackalloc char[7 + hex.Length]; // "sha256:" + hex
+        buffer[0] = 's';
+        buffer[1] = 'h';
+        buffer[2] = 'a';
+        buffer[3] = '2';
+        buffer[4] = '5';
+        buffer[5] = '6';
+        buffer[6] = ':';
+        for (var i = 0; i < hex.Length; i++)
+        {
+            buffer[7 + i] = char.ToLowerInvariant(hex[i]);
+        }
+
+        return new string(buffer);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Exporter.TrivyDb/TrivyDbPackageRequest.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace StellaOps.Feedser.Exporter.TrivyDb;
+
+public sealed record TrivyDbPackageRequest(
+    ReadOnlyMemory<byte> MetadataJson,
+    string DatabaseArchivePath,
+    string DatabaseDigest,
+    long DatabaseLength,
+    DateTimeOffset GeneratedAt,
+    string DatabaseVersion);

src/StellaOps.Feedser/StellaOps.Feedser.Merge/AGENTS.md

@@ -0,0 +1,25 @@
+# AGENTS
+## Role
+Deterministic merge and reconciliation engine; builds identity graph via aliases; applies precedence (PSIRT/OVAL > NVD; KEV flag only; regional feeds enrich); produces canonical advisory JSON and merge_event audit trail.
+## Scope
+- Identity: resolve advisory_key (prefer CVE, else PSIRT/Distro/JVN/BDU/GHSA/ICSA); unify aliases; detect collisions.
+- Precedence: override rules for affected ranges (vendor PSIRT/OVAL over registry), enrichment-only feeds (CERTs/JVN/RU-CERT), KEV toggles exploitKnown only.
+- Range comparers: RPM NEVRA comparer (epoch:version-release), Debian EVR comparer, SemVer range resolver; platform-aware selection.
+- Merge algorithm: stable ordering, pure functions, idempotence; compute beforeHash/afterHash over canonical form; write merge_event.
+- Conflict reporting: counters and logs for identity conflicts, reference merges, range overrides.
+## Participants
+- Storage.Mongo (reads raw mapped advisories, writes merged docs plus merge_event).
+- Models (canonical types).
+- Exporters (consume merged canonical).
+- Core/WebService (jobs: merge:run, maybe per-kind).
+## Interfaces & contracts
+- AdvisoryMergeService.MergeAsync(ids or byKind): returns summary {processed, merged, overrides, conflicts}.
+- Precedence table configurable but with sane defaults: RedHat/Ubuntu/Debian/SUSE > Vendor PSIRT > GHSA/OSV > NVD; CERTs enrich; KEV sets flags.
+- Range selection uses comparers: NevraComparer, DebEvrComparer, SemVerRange; deterministic tie-breakers.
+- Provenance propagation merges unique entries; references deduped by (url, type).
+## In/Out of scope
+In: merge logic, precedence policy, hashing, event records, comparers.
+Out: fetching/parsing, exporter packaging, signing.
+## Observability & security expectations
+- Metrics: merge.delta.count, merge.identity.conflicts, merge.range.overrides, merge.duration_ms.
+- Logs: decisions (why replaced), keys involved, hashes; avoid dumping large blobs; redact secrets (none expected).

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Class1.cs

@@ -1,6 +1 @@
-namespace StellaOps.Feedser.Merge;
-
-public class Class1
-{
-
-}
+// Intentionally left blank; types moved into dedicated files.

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Comparers/DebianEvr.cs

@@ -0,0 +1,232 @@
+namespace StellaOps.Feedser.Merge.Comparers;
+
+using System;
+using StellaOps.Feedser.Normalization.Distro;
+
+public sealed class DebianEvrComparer : IComparer<DebianEvr>, IComparer<string>
+{
+    public static DebianEvrComparer Instance { get; } = new();
+
+    private DebianEvrComparer()
+    {
+    }
+
+    public int Compare(string? x, string? y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return 0;
+        }
+
+        if (x is null)
+        {
+            return -1;
+        }
+
+        if (y is null)
+        {
+            return 1;
+        }
+
+        var xParsed = DebianEvr.TryParse(x, out var xEvr);
+        var yParsed = DebianEvr.TryParse(y, out var yEvr);
+
+        if (xParsed && yParsed)
+        {
+            return Compare(xEvr, yEvr);
+        }
+
+        if (xParsed)
+        {
+            return 1;
+        }
+
+        if (yParsed)
+        {
+            return -1;
+        }
+
+        return string.Compare(x, y, StringComparison.Ordinal);
+    }
+
+    public int Compare(DebianEvr? x, DebianEvr? y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return 0;
+        }
+
+        if (x is null)
+        {
+            return -1;
+        }
+
+        if (y is null)
+        {
+            return 1;
+        }
+
+        var compare = x.Epoch.CompareTo(y.Epoch);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = CompareSegment(x.Version, y.Version);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = CompareSegment(x.Revision, y.Revision);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        return string.Compare(x.Original, y.Original, StringComparison.Ordinal);
+    }
+
+    private static int CompareSegment(string left, string right)
+    {
+        var i = 0;
+        var j = 0;
+
+        while (i < left.Length || j < right.Length)
+        {
+            while (i < left.Length && !IsAlphaNumeric(left[i]) && left[i] != '~')
+            {
+                i++;
+            }
+
+            while (j < right.Length && !IsAlphaNumeric(right[j]) && right[j] != '~')
+            {
+                j++;
+            }
+
+            var leftChar = i < left.Length ? left[i] : '\0';
+            var rightChar = j < right.Length ? right[j] : '\0';
+
+            if (leftChar == '~' || rightChar == '~')
+            {
+                if (leftChar != rightChar)
+                {
+                    return leftChar == '~' ? -1 : 1;
+                }
+
+                i += leftChar == '~' ? 1 : 0;
+                j += rightChar == '~' ? 1 : 0;
+                continue;
+            }
+
+            var leftIsDigit = char.IsDigit(leftChar);
+            var rightIsDigit = char.IsDigit(rightChar);
+
+            if (leftIsDigit && rightIsDigit)
+            {
+                var leftStart = i;
+                while (i < left.Length && char.IsDigit(left[i]))
+                {
+                    i++;
+                }
+
+                var rightStart = j;
+                while (j < right.Length && char.IsDigit(right[j]))
+                {
+                    j++;
+                }
+
+                var leftTrimmed = leftStart;
+                while (leftTrimmed < i && left[leftTrimmed] == '0')
+                {
+                    leftTrimmed++;
+                }
+
+                var rightTrimmed = rightStart;
+                while (rightTrimmed < j && right[rightTrimmed] == '0')
+                {
+                    rightTrimmed++;
+                }
+
+                var leftLength = i - leftTrimmed;
+                var rightLength = j - rightTrimmed;
+
+                if (leftLength != rightLength)
+                {
+                    return leftLength.CompareTo(rightLength);
+                }
+
+                var comparison = left.AsSpan(leftTrimmed, leftLength)
+                    .CompareTo(right.AsSpan(rightTrimmed, rightLength), StringComparison.Ordinal);
+                if (comparison != 0)
+                {
+                    return comparison;
+                }
+
+                continue;
+            }
+
+            if (leftIsDigit)
+            {
+                return 1;
+            }
+
+            if (rightIsDigit)
+            {
+                return -1;
+            }
+
+            var leftOrder = CharOrder(leftChar);
+            var rightOrder = CharOrder(rightChar);
+
+            var orderComparison = leftOrder.CompareTo(rightOrder);
+            if (orderComparison != 0)
+            {
+                return orderComparison;
+            }
+
+            if (leftChar != rightChar)
+            {
+                return leftChar.CompareTo(rightChar);
+            }
+
+            if (leftChar == '\0')
+            {
+                return 0;
+            }
+
+            i++;
+            j++;
+        }
+
+        return 0;
+    }
+
+    private static bool IsAlphaNumeric(char value)
+        => char.IsLetterOrDigit(value);
+
+    private static int CharOrder(char value)
+    {
+        if (value == '\0')
+        {
+            return 0;
+        }
+
+        if (value == '~')
+        {
+            return -1;
+        }
+
+        if (char.IsDigit(value))
+        {
+            return 0;
+        }
+
+        if (char.IsLetter(value))
+        {
+            return value;
+        }
+
+        return value + 256;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Comparers/Nevra.cs

@@ -0,0 +1,264 @@
+namespace StellaOps.Feedser.Merge.Comparers;
+
+using System;
+using StellaOps.Feedser.Normalization.Distro;
+
+public sealed class NevraComparer : IComparer<Nevra>, IComparer<string>
+{
+    public static NevraComparer Instance { get; } = new();
+
+    private NevraComparer()
+    {
+    }
+
+    public int Compare(string? x, string? y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return 0;
+        }
+
+        if (x is null)
+        {
+            return -1;
+        }
+
+        if (y is null)
+        {
+            return 1;
+        }
+
+        var xParsed = Nevra.TryParse(x, out var xNevra);
+        var yParsed = Nevra.TryParse(y, out var yNevra);
+
+        if (xParsed && yParsed)
+        {
+            return Compare(xNevra, yNevra);
+        }
+
+        if (xParsed)
+        {
+            return 1;
+        }
+
+        if (yParsed)
+        {
+            return -1;
+        }
+
+        return string.Compare(x, y, StringComparison.Ordinal);
+    }
+
+    public int Compare(Nevra? x, Nevra? y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return 0;
+        }
+
+        if (x is null)
+        {
+            return -1;
+        }
+
+        if (y is null)
+        {
+            return 1;
+        }
+
+        var compare = string.Compare(x.Name, y.Name, StringComparison.Ordinal);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = string.Compare(x.Architecture ?? string.Empty, y.Architecture ?? string.Empty, StringComparison.Ordinal);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = x.Epoch.CompareTo(y.Epoch);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = RpmVersionComparer.Compare(x.Version, y.Version);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = RpmVersionComparer.Compare(x.Release, y.Release);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        return string.Compare(x.Original, y.Original, StringComparison.Ordinal);
+    }
+}
+
+internal static class RpmVersionComparer
+{
+    public static int Compare(string? left, string? right)
+    {
+        left ??= string.Empty;
+        right ??= string.Empty;
+
+        var i = 0;
+        var j = 0;
+
+        while (true)
+        {
+            var leftHasTilde = SkipToNextSegment(left, ref i);
+            var rightHasTilde = SkipToNextSegment(right, ref j);
+
+            if (leftHasTilde || rightHasTilde)
+            {
+                if (leftHasTilde && rightHasTilde)
+                {
+                    continue;
+                }
+
+                return leftHasTilde ? -1 : 1;
+            }
+
+            var leftEnd = i >= left.Length;
+            var rightEnd = j >= right.Length;
+            if (leftEnd || rightEnd)
+            {
+                if (leftEnd && rightEnd)
+                {
+                    return 0;
+                }
+
+                return leftEnd ? -1 : 1;
+            }
+
+            var leftDigit = char.IsDigit(left[i]);
+            var rightDigit = char.IsDigit(right[j]);
+
+            if (leftDigit && !rightDigit)
+            {
+                return 1;
+            }
+
+            if (!leftDigit && rightDigit)
+            {
+                return -1;
+            }
+
+            int compare;
+            if (leftDigit)
+            {
+                compare = CompareNumericSegment(left, ref i, right, ref j);
+            }
+            else
+            {
+                compare = CompareAlphaSegment(left, ref i, right, ref j);
+            }
+
+            if (compare != 0)
+            {
+                return compare;
+            }
+        }
+    }
+
+    private static bool SkipToNextSegment(string value, ref int index)
+    {
+        var sawTilde = false;
+        while (index < value.Length)
+        {
+            var current = value[index];
+            if (current == '~')
+            {
+                sawTilde = true;
+                index++;
+                break;
+            }
+
+            if (char.IsLetterOrDigit(current))
+            {
+                break;
+            }
+
+            index++;
+        }
+
+        return sawTilde;
+    }
+
+    private static int CompareNumericSegment(string value, ref int index, string other, ref int otherIndex)
+    {
+        var start = index;
+        while (index < value.Length && char.IsDigit(value[index]))
+        {
+            index++;
+        }
+
+        var otherStart = otherIndex;
+        while (otherIndex < other.Length && char.IsDigit(other[otherIndex]))
+        {
+            otherIndex++;
+        }
+
+        var trimmedStart = start;
+        while (trimmedStart < index && value[trimmedStart] == '0')
+        {
+            trimmedStart++;
+        }
+
+        var otherTrimmedStart = otherStart;
+        while (otherTrimmedStart < otherIndex && other[otherTrimmedStart] == '0')
+        {
+            otherTrimmedStart++;
+        }
+
+        var length = index - trimmedStart;
+        var otherLength = otherIndex - otherTrimmedStart;
+
+        if (length != otherLength)
+        {
+            return length.CompareTo(otherLength);
+        }
+
+        var comparison = value.AsSpan(trimmedStart, length)
+            .CompareTo(other.AsSpan(otherTrimmedStart, otherLength), StringComparison.Ordinal);
+        if (comparison != 0)
+        {
+            return comparison;
+        }
+
+        return 0;
+    }
+
+    private static int CompareAlphaSegment(string value, ref int index, string other, ref int otherIndex)
+    {
+        var start = index;
+        while (index < value.Length && char.IsLetter(value[index]))
+        {
+            index++;
+        }
+
+        var otherStart = otherIndex;
+        while (otherIndex < other.Length && char.IsLetter(other[otherIndex]))
+        {
+            otherIndex++;
+        }
+
+        var length = index - start;
+        var otherLength = otherIndex - otherStart;
+
+        var comparison = value.AsSpan(start, length)
+            .CompareTo(other.AsSpan(otherStart, otherLength), StringComparison.Ordinal);
+        if (comparison != 0)
+        {
+            return comparison;
+        }
+
+        return 0;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Comparers/SemanticVersionRangeResolver.cs

@@ -0,0 +1,73 @@
+namespace StellaOps.Feedser.Merge.Comparers;
+
+using System.Diagnostics.CodeAnalysis;
+using Semver;
+
+/// <summary>
+/// Provides helpers to interpret introduced/fixed/lastAffected SemVer ranges and compare versions.
+/// </summary>
+public static class SemanticVersionRangeResolver
+{
+    public static bool TryParse(string? value, [NotNullWhen(true)] out SemVersion? result)
+        => SemVersion.TryParse(value, SemVersionStyles.Any, out result);
+
+    public static SemVersion Parse(string value)
+        => SemVersion.Parse(value, SemVersionStyles.Any);
+
+    /// <summary>
+    /// Resolves the effective start and end versions using introduced/fixed/lastAffected semantics.
+    /// </summary>
+    public static (SemVersion? introduced, SemVersion? exclusiveUpperBound, SemVersion? inclusiveUpperBound) ResolveWindows(
+        string? introduced,
+        string? fixedVersion,
+        string? lastAffected)
+    {
+        var introducedVersion = TryParse(introduced, out var parsedIntroduced) ? parsedIntroduced : null;
+        var fixedVersionParsed = TryParse(fixedVersion, out var parsedFixed) ? parsedFixed : null;
+        var lastAffectedVersion = TryParse(lastAffected, out var parsedLast) ? parsedLast : null;
+
+        SemVersion? exclusiveUpper = null;
+        SemVersion? inclusiveUpper = null;
+
+        if (fixedVersionParsed is not null)
+        {
+            exclusiveUpper = fixedVersionParsed;
+        }
+        else if (lastAffectedVersion is not null)
+        {
+            inclusiveUpper = lastAffectedVersion;
+            exclusiveUpper = NextPatch(lastAffectedVersion);
+        }
+
+        return (introducedVersion, exclusiveUpper, inclusiveUpper);
+    }
+
+
+    public static int Compare(string? left, string? right)
+    {
+        var leftParsed = TryParse(left, out var leftSemver);
+        var rightParsed = TryParse(right, out var rightSemver);
+
+        if (leftParsed && rightParsed)
+        {
+            return SemVersion.CompareSortOrder(leftSemver, rightSemver);
+        }
+
+        if (leftParsed)
+        {
+            return 1;
+        }
+
+        if (rightParsed)
+        {
+            return -1;
+        }
+
+        return string.Compare(left, right, StringComparison.Ordinal);
+    }
+
+    private static SemVersion NextPatch(SemVersion version)
+    {
+        return new SemVersion(version.Major, version.Minor, version.Patch + 1);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Options/AdvisoryPrecedenceOptions.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+
+namespace StellaOps.Feedser.Merge.Options;
+
+/// <summary>
+/// Configurable precedence overrides for advisory sources.
+/// </summary>
+public sealed class AdvisoryPrecedenceOptions
+{
+    /// <summary>
+    /// Mapping of provenance source identifiers to precedence ranks. Lower numbers take precedence.
+    /// </summary>
+    public IDictionary<string, int> Ranks { get; init; } = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Services/AdvisoryPrecedenceMerger.cs

@@ -0,0 +1,296 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.Metrics;
+using System.Linq;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+using StellaOps.Feedser.Merge.Options;
+using StellaOps.Feedser.Models;
+
+namespace StellaOps.Feedser.Merge.Services;
+
+/// <summary>
+/// Merges canonical advisories emitted by different sources into a single precedence-resolved advisory.
+/// </summary>
+public sealed class AdvisoryPrecedenceMerger
+{
+    private static readonly IReadOnlyDictionary<string, int> DefaultPrecedence = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase)
+    {
+        ["redhat"] = 0,
+        ["ubuntu"] = 0,
+        ["debian"] = 0,
+        ["suse"] = 0,
+        ["msrc"] = 1,
+        ["oracle"] = 1,
+        ["adobe"] = 1,
+        ["chromium"] = 1,
+        ["jvn"] = 2,
+        ["certfr"] = 2,
+        ["certin"] = 2,
+        ["ics-kaspersky"] = 2,
+        ["kev"] = 6,
+        ["nvd"] = 5,
+    };
+
+    private static readonly Meter MergeMeter = new("StellaOps.Feedser.Merge");
+    private static readonly Counter<long> OverridesCounter = MergeMeter.CreateCounter<long>(
+        "feedser.merge.overrides",
+        unit: "count",
+        description: "Number of times lower-precedence advisories were overridden by higher-precedence sources.");
+
+    private readonly AffectedPackagePrecedenceResolver _packageResolver;
+    private readonly IReadOnlyDictionary<string, int> _precedence;
+    private readonly int _fallbackRank;
+    private readonly System.TimeProvider _timeProvider;
+    private readonly ILogger<AdvisoryPrecedenceMerger> _logger;
+
+    public AdvisoryPrecedenceMerger()
+        : this(new AffectedPackagePrecedenceResolver(), DefaultPrecedence, System.TimeProvider.System, NullLogger<AdvisoryPrecedenceMerger>.Instance)
+    {
+    }
+
+    public AdvisoryPrecedenceMerger(AffectedPackagePrecedenceResolver packageResolver, System.TimeProvider? timeProvider = null)
+        : this(packageResolver, DefaultPrecedence, timeProvider ?? System.TimeProvider.System, NullLogger<AdvisoryPrecedenceMerger>.Instance)
+    {
+    }
+
+    public AdvisoryPrecedenceMerger(
+        AffectedPackagePrecedenceResolver packageResolver,
+        IReadOnlyDictionary<string, int> precedence,
+        System.TimeProvider timeProvider)
+        : this(packageResolver, precedence, timeProvider, NullLogger<AdvisoryPrecedenceMerger>.Instance)
+    {
+    }
+
+    public AdvisoryPrecedenceMerger(
+        AffectedPackagePrecedenceResolver packageResolver,
+        AdvisoryPrecedenceOptions? options,
+        System.TimeProvider timeProvider,
+        ILogger<AdvisoryPrecedenceMerger>? logger = null)
+        : this(packageResolver, MergePrecedence(DefaultPrecedence, options), timeProvider, logger)
+    {
+    }
+
+    public AdvisoryPrecedenceMerger(
+        AffectedPackagePrecedenceResolver packageResolver,
+        IReadOnlyDictionary<string, int> precedence,
+        System.TimeProvider timeProvider,
+        ILogger<AdvisoryPrecedenceMerger>? logger)
+    {
+        _packageResolver = packageResolver ?? throw new ArgumentNullException(nameof(packageResolver));
+        _precedence = precedence ?? throw new ArgumentNullException(nameof(precedence));
+        _fallbackRank = _precedence.Count == 0 ? 10 : _precedence.Values.Max() + 1;
+        _timeProvider = timeProvider ?? TimeProvider.System;
+        _logger = logger ?? NullLogger<AdvisoryPrecedenceMerger>.Instance;
+    }
+
+    public Advisory Merge(IEnumerable<Advisory> advisories)
+    {
+        if (advisories is null)
+        {
+            throw new ArgumentNullException(nameof(advisories));
+        }
+
+        var list = advisories.Where(static a => a is not null).ToList();
+        if (list.Count == 0)
+        {
+            throw new ArgumentException("At least one advisory is required for merge.", nameof(advisories));
+        }
+
+        var advisoryKey = list[0].AdvisoryKey;
+        if (list.Any(advisory => !string.Equals(advisory.AdvisoryKey, advisoryKey, StringComparison.Ordinal)))
+        {
+            throw new ArgumentException("All advisories must share the same advisory key.", nameof(advisories));
+        }
+
+        var ordered = list
+            .Select(advisory => new AdvisoryEntry(advisory, GetRank(advisory)))
+            .OrderBy(entry => entry.Rank)
+            .ThenByDescending(entry => entry.Advisory.Provenance.Length)
+            .ToArray();
+
+        var primary = ordered[0].Advisory;
+
+        var title = PickString(ordered, advisory => advisory.Title) ?? advisoryKey;
+        var summary = PickString(ordered, advisory => advisory.Summary);
+        var language = PickString(ordered, advisory => advisory.Language);
+        var severity = PickString(ordered, advisory => advisory.Severity);
+
+        var aliases = ordered
+            .SelectMany(entry => entry.Advisory.Aliases)
+            .Where(static alias => !string.IsNullOrWhiteSpace(alias))
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+
+        var references = ordered
+            .SelectMany(entry => entry.Advisory.References)
+            .Distinct()
+            .ToArray();
+
+        var affectedPackages = _packageResolver.Merge(ordered.SelectMany(entry => entry.Advisory.AffectedPackages));
+        var cvssMetrics = ordered
+            .SelectMany(entry => entry.Advisory.CvssMetrics)
+            .Distinct()
+            .ToArray();
+
+        var published = PickDateTime(ordered, static advisory => advisory.Published);
+        var modified = PickDateTime(ordered, static advisory => advisory.Modified) ?? published;
+
+        var provenance = ordered
+            .SelectMany(entry => entry.Advisory.Provenance)
+            .Distinct()
+            .ToList();
+
+        var precedenceTrace = ordered
+            .SelectMany(entry => entry.Sources)
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .OrderBy(static source => source, StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+
+        var mergeProvenance = new AdvisoryProvenance(
+            source: "merge",
+            kind: "precedence",
+            value: string.Join("|", precedenceTrace),
+            recordedAt: _timeProvider.GetUtcNow());
+
+        provenance.Add(mergeProvenance);
+
+        var exploitKnown = ordered.Any(entry => entry.Advisory.ExploitKnown);
+
+        LogOverrides(advisoryKey, ordered);
+
+        return new Advisory(
+            advisoryKey,
+            title,
+            summary,
+            language,
+            published,
+            modified,
+            severity,
+            exploitKnown,
+            aliases,
+            references,
+            affectedPackages,
+            cvssMetrics,
+            provenance);
+    }
+
+    private string? PickString(IEnumerable<AdvisoryEntry> ordered, Func<Advisory, string?> selector)
+    {
+        foreach (var entry in ordered)
+        {
+            var value = selector(entry.Advisory);
+            if (!string.IsNullOrWhiteSpace(value))
+            {
+                return value.Trim();
+            }
+        }
+
+        return null;
+    }
+
+    private DateTimeOffset? PickDateTime(IEnumerable<AdvisoryEntry> ordered, Func<Advisory, DateTimeOffset?> selector)
+    {
+        foreach (var entry in ordered)
+        {
+            var value = selector(entry.Advisory);
+            if (value.HasValue)
+            {
+                return value.Value.ToUniversalTime();
+            }
+        }
+
+        return null;
+    }
+
+    private int GetRank(Advisory advisory)
+    {
+        var best = _fallbackRank;
+        foreach (var provenance in advisory.Provenance)
+        {
+            if (string.IsNullOrWhiteSpace(provenance.Source))
+            {
+                continue;
+            }
+
+            if (_precedence.TryGetValue(provenance.Source, out var rank) && rank < best)
+            {
+                best = rank;
+            }
+        }
+
+        return best;
+    }
+
+    private static IReadOnlyDictionary<string, int> MergePrecedence(
+        IReadOnlyDictionary<string, int> defaults,
+        AdvisoryPrecedenceOptions? options)
+    {
+        if (options?.Ranks is null || options.Ranks.Count == 0)
+        {
+            return defaults;
+        }
+
+        var merged = new Dictionary<string, int>(defaults, StringComparer.OrdinalIgnoreCase);
+        foreach (var kvp in options.Ranks)
+        {
+            if (string.IsNullOrWhiteSpace(kvp.Key))
+            {
+                continue;
+            }
+
+            merged[kvp.Key.Trim()] = kvp.Value;
+        }
+
+        return merged;
+    }
+
+    private void LogOverrides(string advisoryKey, IReadOnlyList<AdvisoryEntry> ordered)
+    {
+        if (ordered.Count <= 1)
+        {
+            return;
+        }
+
+        var primary = ordered[0];
+        var primaryRank = primary.Rank;
+        var primarySources = string.Join(',', primary.Sources);
+
+        for (var i = 1; i < ordered.Count; i++)
+        {
+            var candidate = ordered[i];
+            if (candidate.Rank <= primaryRank)
+            {
+                continue;
+            }
+
+            var suppressedSources = string.Join(',', candidate.Sources);
+
+            OverridesCounter.Add(
+                1,
+                new KeyValuePair<string, object?>[]
+                {
+                    new("advisory", advisoryKey),
+                    new("primary_sources", primarySources),
+                    new("suppressed_sources", suppressedSources),
+                });
+
+            _logger.LogInformation(
+                "Advisory precedence override for {AdvisoryKey}: kept {PrimarySources} (rank {PrimaryRank}) over {SuppressedSources} (rank {SuppressedRank})",
+                advisoryKey,
+                primarySources,
+                primaryRank,
+                suppressedSources,
+                candidate.Rank);
+        }
+    }
+
+    private readonly record struct AdvisoryEntry(Advisory Advisory, int Rank)
+    {
+        public IReadOnlyCollection<string> Sources { get; } = Advisory.Provenance
+            .Select(static p => p.Source)
+            .Where(static source => !string.IsNullOrWhiteSpace(source))
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Services/AffectedPackagePrecedenceResolver.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using StellaOps.Feedser.Models;
+
+namespace StellaOps.Feedser.Merge.Services;
+
+/// <summary>
+/// Applies source precedence rules to affected package sets so authoritative distro ranges override generic registry data.
+/// </summary>
+public sealed class AffectedPackagePrecedenceResolver
+{
+    private static readonly IReadOnlyDictionary<string, int> DefaultPrecedence = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase)
+    {
+        ["redhat"] = 0,
+        ["ubuntu"] = 0,
+        ["debian"] = 0,
+        ["suse"] = 0,
+        ["msrc"] = 1,
+        ["oracle"] = 1,
+        ["adobe"] = 1,
+        ["chromium"] = 1,
+        ["nvd"] = 5,
+    };
+
+    private readonly IReadOnlyDictionary<string, int> _precedence;
+    private readonly int _fallbackRank;
+
+    public AffectedPackagePrecedenceResolver()
+        : this(DefaultPrecedence)
+    {
+    }
+
+    public AffectedPackagePrecedenceResolver(IReadOnlyDictionary<string, int> precedence)
+    {
+        _precedence = precedence ?? throw new ArgumentNullException(nameof(precedence));
+        _fallbackRank = precedence.Count == 0 ? 10 : precedence.Values.Max() + 1;
+    }
+
+    public IReadOnlyList<AffectedPackage> Merge(IEnumerable<AffectedPackage> packages)
+    {
+        ArgumentNullException.ThrowIfNull(packages);
+
+        var grouped = packages
+            .Where(static pkg => pkg is not null)
+            .GroupBy(pkg => (pkg.Type, pkg.Identifier, pkg.Platform ?? string.Empty));
+
+        var resolved = new List<AffectedPackage>();
+        foreach (var group in grouped)
+        {
+            var ordered = group
+                .OrderBy(GetPrecedence)
+                .ThenByDescending(static pkg => pkg.Provenance.Length)
+                .ThenByDescending(static pkg => pkg.VersionRanges.Length);
+
+            var primary = ordered.First();
+            var provenance = ordered
+                .SelectMany(static pkg => pkg.Provenance)
+                .Where(static p => p is not null)
+                .Distinct()
+                .ToImmutableArray();
+
+            var statuses = ordered
+                .SelectMany(static pkg => pkg.Statuses)
+                .Distinct(AffectedPackageStatusEqualityComparer.Instance)
+                .ToImmutableArray();
+
+            var merged = new AffectedPackage(
+                primary.Type,
+                primary.Identifier,
+                string.IsNullOrWhiteSpace(primary.Platform) ? null : primary.Platform,
+                primary.VersionRanges,
+                statuses,
+                provenance);
+
+            resolved.Add(merged);
+        }
+
+        return resolved
+            .OrderBy(static pkg => pkg.Type, StringComparer.Ordinal)
+            .ThenBy(static pkg => pkg.Identifier, StringComparer.Ordinal)
+            .ThenBy(static pkg => pkg.Platform, StringComparer.Ordinal)
+            .ToImmutableArray();
+    }
+
+    private int GetPrecedence(AffectedPackage package)
+    {
+        var bestRank = _fallbackRank;
+        foreach (var provenance in package.Provenance)
+        {
+            if (provenance is null || string.IsNullOrWhiteSpace(provenance.Source))
+            {
+                continue;
+            }
+
+            if (_precedence.TryGetValue(provenance.Source, out var rank) && rank < bestRank)
+            {
+                bestRank = rank;
+            }
+        }
+
+        return bestRank;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Services/CanonicalHashCalculator.cs

@@ -0,0 +1,25 @@
+namespace StellaOps.Feedser.Merge.Services;
+
+using System.Security.Cryptography;
+using System.Text;
+using StellaOps.Feedser.Models;
+
+/// <summary>
+/// Computes deterministic hashes over canonical advisory JSON payloads.
+/// </summary>
+public sealed class CanonicalHashCalculator
+{
+    private static readonly UTF8Encoding Utf8NoBom = new(false);
+
+    public byte[] ComputeHash(Advisory? advisory)
+    {
+        if (advisory is null)
+        {
+            return Array.Empty<byte>();
+        }
+
+        var canonical = CanonicalJsonSerializer.Serialize(CanonicalJsonSerializer.Normalize(advisory));
+        var payload = Utf8NoBom.GetBytes(canonical);
+        return SHA256.HashData(payload);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/Services/MergeEventWriter.cs

@@ -0,0 +1,70 @@
+namespace StellaOps.Feedser.Merge.Services;
+
+using System.Security.Cryptography;
+using System.Linq;
+using Microsoft.Extensions.Logging;
+using StellaOps.Feedser.Models;
+using StellaOps.Feedser.Storage.Mongo.MergeEvents;
+
+/// <summary>
+/// Persists merge events with canonical before/after hashes for auditability.
+/// </summary>
+public sealed class MergeEventWriter
+{
+    private readonly IMergeEventStore _mergeEventStore;
+    private readonly CanonicalHashCalculator _hashCalculator;
+    private readonly TimeProvider _timeProvider;
+    private readonly ILogger<MergeEventWriter> _logger;
+
+    public MergeEventWriter(
+        IMergeEventStore mergeEventStore,
+        CanonicalHashCalculator hashCalculator,
+        TimeProvider timeProvider,
+        ILogger<MergeEventWriter> logger)
+    {
+        _mergeEventStore = mergeEventStore ?? throw new ArgumentNullException(nameof(mergeEventStore));
+        _hashCalculator = hashCalculator ?? throw new ArgumentNullException(nameof(hashCalculator));
+        _timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task<MergeEventRecord> AppendAsync(
+        string advisoryKey,
+        Advisory? before,
+        Advisory after,
+        IReadOnlyList<Guid> inputDocumentIds,
+        CancellationToken cancellationToken)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(advisoryKey);
+        ArgumentNullException.ThrowIfNull(after);
+
+        var beforeHash = _hashCalculator.ComputeHash(before);
+        var afterHash = _hashCalculator.ComputeHash(after);
+        var timestamp = _timeProvider.GetUtcNow();
+        var documentIds = inputDocumentIds?.ToArray() ?? Array.Empty<Guid>();
+
+        var record = new MergeEventRecord(
+            Guid.NewGuid(),
+            advisoryKey,
+            beforeHash,
+            afterHash,
+            timestamp,
+            documentIds);
+
+        if (!CryptographicOperations.FixedTimeEquals(beforeHash, afterHash))
+        {
+            _logger.LogInformation(
+                "Merge event for {AdvisoryKey} changed hash {BeforeHash} -> {AfterHash}",
+                advisoryKey,
+                Convert.ToHexString(beforeHash),
+                Convert.ToHexString(afterHash));
+        }
+        else
+        {
+            _logger.LogInformation("Merge event for {AdvisoryKey} recorded without hash change", advisoryKey);
+        }
+
+        await _mergeEventStore.AppendAsync(record, cancellationToken).ConfigureAwait(false);
+        return record;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Merge/StellaOps.Feedser.Merge.csproj

@@ -1,4 +1,5 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
@@ -7,7 +8,9 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Semver" Version="2.3.0" />
     <ProjectReference Include="../StellaOps.Feedser.Models/StellaOps.Feedser.Models.csproj" />
     <ProjectReference Include="../StellaOps.Feedser.Normalization/StellaOps.Feedser.Normalization.csproj" />
+    <ProjectReference Include="../StellaOps.Feedser.Storage.Mongo/StellaOps.Feedser.Storage.Mongo.csproj" />
   </ItemGroup>
 </Project>

src/StellaOps.Feedser/StellaOps.Feedser.Merge/TASKS.md

@@ -0,0 +1,13 @@
+# TASKS
+| Task | Owner(s) | Depends on | Notes |
+|---|---|---|---|
+|Identity graph and alias resolver|BE-Merge|Models, Storage.Mongo|Deterministic key choice; cycle-safe.|
+|Precedence policy engine|BE-Merge|Architecture|PSIRT/OVAL > NVD; CERTs enrich; KEV flag.|
+|NEVRA comparer plus tests|BE-Merge (Distro WG)|Source.Distro fixtures|DONE – Added Nevra parser/comparer with tilde-aware rpm ordering and unit coverage.|
+|Debian EVR comparer plus tests|BE-Merge (Distro WG)|Debian fixtures|DONE – DebianEvr comparer mirrors dpkg ordering with tilde/epoch handling and unit coverage.|
+|SemVer range resolver plus tests|BE-Merge (OSS WG)|OSV/GHSA fixtures|DONE – SemanticVersionRangeResolver covers introduced/fixed/lastAffected semantics with SemVer ordering tests.|
+|Canonical hash and merge_event writer|BE-Merge|Models, Storage.Mongo|DONE – Hash calculator + MergeEventWriter compute canonical SHA-256 digests and persist merge events.|
+|Conflict detection and metrics|BE-Merge|Core|Counters; structured logs; traces.|
+|End-to-end determinism test|QA|Merge, key connectors|Same inputs -> same hashes.|
+|Override audit logging|BE-Merge|Observability|DOING – structured override logging and metrics emitted; await production telemetry review.|
+|Configurable precedence table|BE-Merge|Architecture|DOING – precedence overrides now accepted via options; document operator workflow.|

src/StellaOps.Feedser/StellaOps.Feedser.Models/AGENTS.md

@@ -0,0 +1,25 @@
+# AGENTS
+## Role
+Canonical data model for normalized advisories and all downstream serialization. Source of truth for merge/export.
+## Scope
+- Canonical types: Advisory, AdvisoryReference, CvssMetric, AffectedPackage, AffectedVersionRange, AdvisoryProvenance.
+- Invariants: stable ordering, culture-invariant serialization, UTC timestamps, deterministic equality semantics.
+- Field semantics: preserve all aliases/references; ranges per ecosystem (NEVRA/EVR/SemVer); provenance on every mapped field.
+- Backward/forward compatibility: additive evolution; versioned DTOs where needed; no breaking field renames.
+- Detailed field coverage documented in `CANONICAL_RECORDS.md`; update alongside model changes.
+## Participants
+- Source connectors map external DTOs into these types.
+- Merge engine composes/overrides AffectedPackage sets and consolidates references/aliases.
+- Exporters serialize canonical documents deterministically.
+## Interfaces & contracts
+- Null-object statics: Advisory.Empty, AdvisoryReference.Empty, CvssMetric.Empty.
+- AffectedPackage.Type describes semantics (e.g., rpm, deb, cpe, semver). Identifier is stable (e.g., NEVRA, PURL, CPE).
+- Version ranges list is ordered by introduction then fix; provenance identifies source/kind/value/recordedAt.
+- Alias schemes must include CVE, GHSA, OSV, JVN/JVNDB, BDU, VU(CERT/CC), MSRC, CISCO-SA, ORACLE-CPU, APSB/APA, APPLE-HT, CHROMIUM-POST, VMSA, RHSA, USN, DSA, SUSE-SU, ICSA, CWE, CPE, PURL.
+## In/Out of scope
+In: data shapes, invariants, helpers for canonical serialization and comparison.
+Out: fetching/parsing external schemas, storage, HTTP.
+## Observability & security expectations
+- No secrets; purely in-memory types.
+- Provide debug renders for test snapshots (canonical JSON).
+- Emit model version identifiers in logs when canonical structures change; keep adapters for older readers until deprecated.

src/StellaOps.Feedser/StellaOps.Feedser.Models/Advisory.cs

@@ -0,0 +1,145 @@
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Canonical advisory document produced after merge. Collections are pre-sorted for deterministic serialization.
+/// </summary>
+public sealed record Advisory
+{
+    public static Advisory Empty { get; } = new(
+        advisoryKey: "unknown",
+        title: "",
+        summary: null,
+        language: null,
+        published: null,
+        modified: null,
+        severity: null,
+        exploitKnown: false,
+        aliases: Array.Empty<string>(),
+        references: Array.Empty<AdvisoryReference>(),
+        affectedPackages: Array.Empty<AffectedPackage>(),
+        cvssMetrics: Array.Empty<CvssMetric>(),
+        provenance: Array.Empty<AdvisoryProvenance>());
+
+    public Advisory(
+        string advisoryKey,
+        string title,
+        string? summary,
+        string? language,
+        DateTimeOffset? published,
+        DateTimeOffset? modified,
+        string? severity,
+        bool exploitKnown,
+        IEnumerable<string>? aliases,
+        IEnumerable<AdvisoryReference>? references,
+        IEnumerable<AffectedPackage>? affectedPackages,
+        IEnumerable<CvssMetric>? cvssMetrics,
+        IEnumerable<AdvisoryProvenance>? provenance)
+    {
+        AdvisoryKey = Validation.EnsureNotNullOrWhiteSpace(advisoryKey, nameof(advisoryKey));
+        Title = Validation.EnsureNotNullOrWhiteSpace(title, nameof(title));
+        Summary = Validation.TrimToNull(summary);
+        Language = Validation.TrimToNull(language)?.ToLowerInvariant();
+        Published = published?.ToUniversalTime();
+        Modified = modified?.ToUniversalTime();
+        Severity = SeverityNormalization.Normalize(severity);
+        ExploitKnown = exploitKnown;
+
+        Aliases = (aliases ?? Array.Empty<string>())
+            .Select(static alias => Validation.TryNormalizeAlias(alias, out var normalized) ? normalized! : null)
+            .Where(static alias => alias is not null)
+            .Distinct(StringComparer.Ordinal)
+            .OrderBy(static alias => alias, StringComparer.Ordinal)
+            .Select(static alias => alias!)
+            .ToImmutableArray();
+
+        References = (references ?? Array.Empty<AdvisoryReference>())
+            .Where(static reference => reference is not null)
+            .OrderBy(static reference => reference.Url, StringComparer.Ordinal)
+            .ThenBy(static reference => reference.Kind, StringComparer.Ordinal)
+            .ThenBy(static reference => reference.SourceTag, StringComparer.Ordinal)
+            .ThenBy(static reference => reference.Provenance.RecordedAt)
+            .ToImmutableArray();
+
+        AffectedPackages = (affectedPackages ?? Array.Empty<AffectedPackage>())
+            .Where(static package => package is not null)
+            .OrderBy(static package => package.Type, StringComparer.Ordinal)
+            .ThenBy(static package => package.Identifier, StringComparer.Ordinal)
+            .ThenBy(static package => package.Platform, StringComparer.Ordinal)
+            .ToImmutableArray();
+
+        CvssMetrics = (cvssMetrics ?? Array.Empty<CvssMetric>())
+            .Where(static metric => metric is not null)
+            .OrderBy(static metric => metric.Version, StringComparer.Ordinal)
+            .ThenBy(static metric => metric.Vector, StringComparer.Ordinal)
+            .ToImmutableArray();
+
+        Provenance = (provenance ?? Array.Empty<AdvisoryProvenance>())
+            .Where(static p => p is not null)
+            .OrderBy(static p => p.Source, StringComparer.Ordinal)
+            .ThenBy(static p => p.Kind, StringComparer.Ordinal)
+            .ThenBy(static p => p.RecordedAt)
+            .ToImmutableArray();
+    }
+
+    [JsonConstructor]
+    public Advisory(
+        string advisoryKey,
+        string title,
+        string? summary,
+        string? language,
+        DateTimeOffset? published,
+        DateTimeOffset? modified,
+        string? severity,
+        bool exploitKnown,
+        ImmutableArray<string> aliases,
+        ImmutableArray<AdvisoryReference> references,
+        ImmutableArray<AffectedPackage> affectedPackages,
+        ImmutableArray<CvssMetric> cvssMetrics,
+        ImmutableArray<AdvisoryProvenance> provenance)
+        : this(
+            advisoryKey,
+            title,
+            summary,
+            language,
+            published,
+            modified,
+            severity,
+            exploitKnown,
+            aliases.IsDefault ? null : aliases.AsEnumerable(),
+            references.IsDefault ? null : references.AsEnumerable(),
+            affectedPackages.IsDefault ? null : affectedPackages.AsEnumerable(),
+            cvssMetrics.IsDefault ? null : cvssMetrics.AsEnumerable(),
+            provenance.IsDefault ? null : provenance.AsEnumerable())
+    {
+    }
+
+    public string AdvisoryKey { get; }
+
+    public string Title { get; }
+
+    public string? Summary { get; }
+
+    public string? Language { get; }
+
+    public DateTimeOffset? Published { get; }
+
+    public DateTimeOffset? Modified { get; }
+
+    public string? Severity { get; }
+
+    public bool ExploitKnown { get; }
+
+    public ImmutableArray<string> Aliases { get; }
+
+    public ImmutableArray<AdvisoryReference> References { get; }
+
+    public ImmutableArray<AffectedPackage> AffectedPackages { get; }
+
+    public ImmutableArray<CvssMetric> CvssMetrics { get; }
+
+    public ImmutableArray<AdvisoryProvenance> Provenance { get; }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AdvisoryProvenance.cs

@@ -0,0 +1,28 @@
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Describes the origin of a canonical field and how/when it was captured.
+/// </summary>
+public sealed record AdvisoryProvenance
+{
+    public static AdvisoryProvenance Empty { get; } = new("unknown", "unspecified", string.Empty, DateTimeOffset.UnixEpoch);
+
+    [JsonConstructor]
+    public AdvisoryProvenance(string source, string kind, string value, DateTimeOffset recordedAt)
+    {
+        Source = Validation.EnsureNotNullOrWhiteSpace(source, nameof(source));
+        Kind = Validation.EnsureNotNullOrWhiteSpace(kind, nameof(kind));
+        Value = Validation.TrimToNull(value);
+        RecordedAt = recordedAt.ToUniversalTime();
+    }
+
+    public string Source { get; }
+
+    public string Kind { get; }
+
+    public string? Value { get; }
+
+    public DateTimeOffset RecordedAt { get; }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AdvisoryReference.cs

@@ -0,0 +1,36 @@
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Canonical external reference associated with an advisory.
+/// </summary>
+public sealed record AdvisoryReference
+{
+    public static AdvisoryReference Empty { get; } = new("https://invalid.local/", kind: null, sourceTag: null, summary: null, provenance: AdvisoryProvenance.Empty);
+
+    [JsonConstructor]
+    public AdvisoryReference(string url, string? kind, string? sourceTag, string? summary, AdvisoryProvenance provenance)
+    {
+        if (!Validation.LooksLikeHttpUrl(url))
+        {
+            throw new ArgumentException("Reference URL must be an absolute http(s) URI.", nameof(url));
+        }
+
+        Url = url;
+        Kind = Validation.TrimToNull(kind);
+        SourceTag = Validation.TrimToNull(sourceTag);
+        Summary = Validation.TrimToNull(summary);
+        Provenance = provenance ?? AdvisoryProvenance.Empty;
+    }
+
+    public string Url { get; }
+
+    public string? Kind { get; }
+
+    public string? SourceTag { get; }
+
+    public string? Summary { get; }
+
+    public AdvisoryProvenance Provenance { get; }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AffectedPackage.cs

@@ -0,0 +1,87 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Canonical affected package descriptor with deterministic ordering of ranges and provenance.
+/// </summary>
+public sealed record AffectedPackage
+{
+    public static AffectedPackage Empty { get; } = new(
+        AffectedPackageTypes.SemVer,
+        identifier: "unknown",
+        platform: null,
+        versionRanges: Array.Empty<AffectedVersionRange>(),
+        statuses: Array.Empty<AffectedPackageStatus>(),
+        provenance: Array.Empty<AdvisoryProvenance>());
+
+    [JsonConstructor]
+    public AffectedPackage(
+        string type,
+        string identifier,
+        string? platform = null,
+        IEnumerable<AffectedVersionRange>? versionRanges = null,
+        IEnumerable<AffectedPackageStatus>? statuses = null,
+        IEnumerable<AdvisoryProvenance>? provenance = null)
+    {
+        Type = Validation.EnsureNotNullOrWhiteSpace(type, nameof(type)).ToLowerInvariant();
+        Identifier = Validation.EnsureNotNullOrWhiteSpace(identifier, nameof(identifier));
+        Platform = Validation.TrimToNull(platform);
+
+        VersionRanges = (versionRanges ?? Array.Empty<AffectedVersionRange>())
+            .Distinct(AffectedVersionRangeEqualityComparer.Instance)
+            .OrderBy(static range => range, AffectedVersionRangeComparer.Instance)
+            .ToImmutableArray();
+
+        Statuses = (statuses ?? Array.Empty<AffectedPackageStatus>())
+            .Where(static status => status is not null)
+            .Distinct(AffectedPackageStatusEqualityComparer.Instance)
+            .OrderBy(static status => status.Status, StringComparer.Ordinal)
+            .ThenBy(static status => status.Provenance.Source, StringComparer.Ordinal)
+            .ThenBy(static status => status.Provenance.Kind, StringComparer.Ordinal)
+            .ThenBy(static status => status.Provenance.RecordedAt)
+            .ToImmutableArray();
+
+        Provenance = (provenance ?? Array.Empty<AdvisoryProvenance>())
+            .Where(static p => p is not null)
+            .OrderBy(static p => p.Source, StringComparer.Ordinal)
+            .ThenBy(static p => p.Kind, StringComparer.Ordinal)
+            .ThenBy(static p => p.RecordedAt)
+            .ToImmutableArray();
+    }
+
+    /// <summary>
+    /// Semantic type of the coordinates (rpm, deb, cpe, semver, vendor, ics-vendor).
+    /// </summary>
+    public string Type { get; }
+
+    /// <summary>
+    /// Canonical identifier for the package (NEVRA, PackageURL, CPE string, vendor slug, etc.).
+    /// </summary>
+    public string Identifier { get; }
+
+    public string? Platform { get; }
+
+    public ImmutableArray<AffectedVersionRange> VersionRanges { get; }
+
+    public ImmutableArray<AffectedPackageStatus> Statuses { get; }
+
+    public ImmutableArray<AdvisoryProvenance> Provenance { get; }
+}
+
+/// <summary>
+/// Known values for <see cref="AffectedPackage.Type"/>.
+/// </summary>
+public static class AffectedPackageTypes
+{
+    public const string Rpm = "rpm";
+    public const string Deb = "deb";
+    public const string Cpe = "cpe";
+    public const string SemVer = "semver";
+    public const string Vendor = "vendor";
+    public const string IcsVendor = "ics-vendor";
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AffectedPackageStatus.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Represents a vendor-supplied status tag for an affected package when a concrete version range is unavailable or supplementary.
+/// </summary>
+public sealed record AffectedPackageStatus
+{
+    [JsonConstructor]
+    public AffectedPackageStatus(string status, AdvisoryProvenance provenance)
+    {
+        Status = AffectedPackageStatusCatalog.Normalize(status);
+        Provenance = provenance ?? AdvisoryProvenance.Empty;
+    }
+
+    public string Status { get; }
+
+    public AdvisoryProvenance Provenance { get; }
+}
+
+public sealed class AffectedPackageStatusEqualityComparer : IEqualityComparer<AffectedPackageStatus>
+{
+    public static AffectedPackageStatusEqualityComparer Instance { get; } = new();
+
+    public bool Equals(AffectedPackageStatus? x, AffectedPackageStatus? y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return true;
+        }
+
+        if (x is null || y is null)
+        {
+            return false;
+        }
+
+        return string.Equals(x.Status, y.Status, StringComparison.Ordinal)
+            && EqualityComparer<AdvisoryProvenance>.Default.Equals(x.Provenance, y.Provenance);
+    }
+
+    public int GetHashCode(AffectedPackageStatus obj)
+        => HashCode.Combine(obj.Status, obj.Provenance);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AffectedPackageStatusCatalog.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Generic;
+
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Central registry of allowed affected-package status labels to keep connectors consistent.
+/// </summary>
+public static class AffectedPackageStatusCatalog
+{
+    public const string KnownAffected = "known_affected";
+    public const string KnownNotAffected = "known_not_affected";
+    public const string UnderInvestigation = "under_investigation";
+    public const string Fixed = "fixed";
+    public const string FirstFixed = "first_fixed";
+    public const string Mitigated = "mitigated";
+    public const string NotApplicable = "not_applicable";
+    public const string Affected = "affected";
+    public const string NotAffected = "not_affected";
+    public const string Pending = "pending";
+    public const string Unknown = "unknown";
+
+    private static readonly HashSet<string> AllowedStatuses = new(StringComparer.OrdinalIgnoreCase)
+    {
+        KnownAffected,
+        KnownNotAffected,
+        UnderInvestigation,
+        Fixed,
+        FirstFixed,
+        Mitigated,
+        NotApplicable,
+        Affected,
+        NotAffected,
+        Pending,
+        Unknown,
+    };
+
+    public static IReadOnlyCollection<string> Allowed => AllowedStatuses;
+
+    public static string Normalize(string status)
+    {
+        if (string.IsNullOrWhiteSpace(status))
+        {
+            throw new ArgumentException("Status must be provided.", nameof(status));
+        }
+
+        var token = status.Trim().ToLowerInvariant().Replace(' ', '_').Replace('-', '_');
+        if (!AllowedStatuses.Contains(token))
+        {
+            throw new ArgumentOutOfRangeException(nameof(status), status, "Status is not part of the allowed affected-package status glossary.");
+        }
+
+        return token;
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AffectedVersionRange.cs

@@ -0,0 +1,145 @@
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Describes a contiguous range of versions impacted by an advisory.
+/// </summary>
+public sealed record AffectedVersionRange
+{
+    [JsonConstructor]
+    public AffectedVersionRange(
+        string rangeKind,
+        string? introducedVersion,
+        string? fixedVersion,
+        string? lastAffectedVersion,
+        string? rangeExpression,
+        AdvisoryProvenance provenance)
+    {
+        RangeKind = Validation.EnsureNotNullOrWhiteSpace(rangeKind, nameof(rangeKind)).ToLowerInvariant();
+        IntroducedVersion = Validation.TrimToNull(introducedVersion);
+        FixedVersion = Validation.TrimToNull(fixedVersion);
+        LastAffectedVersion = Validation.TrimToNull(lastAffectedVersion);
+        RangeExpression = Validation.TrimToNull(rangeExpression);
+        Provenance = provenance ?? AdvisoryProvenance.Empty;
+    }
+
+    /// <summary>
+    /// Semantic kind of the range (e.g., semver, nevra, evr).
+    /// </summary>
+    public string RangeKind { get; }
+
+    /// <summary>
+    /// Inclusive version where impact begins.
+    /// </summary>
+    public string? IntroducedVersion { get; }
+
+    /// <summary>
+    /// Exclusive version where impact ends due to a fix.
+    /// </summary>
+    public string? FixedVersion { get; }
+
+    /// <summary>
+    /// Inclusive upper bound where the vendor reports exposure (when no fix available).
+    /// </summary>
+    public string? LastAffectedVersion { get; }
+
+    /// <summary>
+    /// Normalized textual representation of the range (fallback).
+    /// </summary>
+    public string? RangeExpression { get; }
+
+    public AdvisoryProvenance Provenance { get; }
+
+    public string CreateDeterministicKey()
+        => string.Join('|', RangeKind, IntroducedVersion ?? string.Empty, FixedVersion ?? string.Empty, LastAffectedVersion ?? string.Empty, RangeExpression ?? string.Empty);
+}
+
+/// <summary>
+/// Deterministic comparer for version ranges. Orders by introduced, fixed, last affected, expression, kind.
+/// </summary>
+public sealed class AffectedVersionRangeComparer : IComparer<AffectedVersionRange>
+{
+    public static AffectedVersionRangeComparer Instance { get; } = new();
+
+    private static readonly StringComparer Comparer = StringComparer.Ordinal;
+
+    public int Compare(AffectedVersionRange? x, AffectedVersionRange? y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return 0;
+        }
+
+        if (x is null)
+        {
+            return -1;
+        }
+
+        if (y is null)
+        {
+            return 1;
+        }
+
+        var compare = Comparer.Compare(x.IntroducedVersion, y.IntroducedVersion);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = Comparer.Compare(x.FixedVersion, y.FixedVersion);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = Comparer.Compare(x.LastAffectedVersion, y.LastAffectedVersion);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        compare = Comparer.Compare(x.RangeExpression, y.RangeExpression);
+        if (compare != 0)
+        {
+            return compare;
+        }
+
+        return Comparer.Compare(x.RangeKind, y.RangeKind);
+    }
+}
+
+/// <summary>
+/// Equality comparer that ignores provenance differences.
+/// </summary>
+public sealed class AffectedVersionRangeEqualityComparer : IEqualityComparer<AffectedVersionRange>
+{
+    public static AffectedVersionRangeEqualityComparer Instance { get; } = new();
+
+    public bool Equals(AffectedVersionRange? x, AffectedVersionRange? y)
+    {
+        if (ReferenceEquals(x, y))
+        {
+            return true;
+        }
+
+        if (x is null || y is null)
+        {
+            return false;
+        }
+
+        return string.Equals(x.RangeKind, y.RangeKind, StringComparison.Ordinal)
+            && string.Equals(x.IntroducedVersion, y.IntroducedVersion, StringComparison.Ordinal)
+            && string.Equals(x.FixedVersion, y.FixedVersion, StringComparison.Ordinal)
+            && string.Equals(x.LastAffectedVersion, y.LastAffectedVersion, StringComparison.Ordinal)
+            && string.Equals(x.RangeExpression, y.RangeExpression, StringComparison.Ordinal);
+    }
+
+    public int GetHashCode(AffectedVersionRange obj)
+        => HashCode.Combine(
+            obj.RangeKind,
+            obj.IntroducedVersion,
+            obj.FixedVersion,
+            obj.LastAffectedVersion,
+            obj.RangeExpression);
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AliasSchemeRegistry.cs

@@ -0,0 +1,166 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text.RegularExpressions;
+
+namespace StellaOps.Feedser.Models;
+
+public static class AliasSchemeRegistry
+{
+    private sealed record AliasScheme(
+        string Name,
+        Func<string?, bool> Predicate,
+        Func<string?, string> Normalizer);
+
+private static readonly AliasScheme[] SchemeDefinitions =
+    {
+        BuildScheme(AliasSchemes.Cve, alias => alias is not null && Matches(CvERegex, alias), alias => alias is null ? string.Empty : NormalizePrefix(alias, "CVE")),
+        BuildScheme(AliasSchemes.Ghsa, alias => alias is not null && Matches(GhsaRegex, alias), alias => alias is null ? string.Empty : NormalizePrefix(alias, "GHSA")),
+        BuildScheme(AliasSchemes.OsV, alias => alias is not null && Matches(OsVRegex, alias), alias => alias is null ? string.Empty : NormalizePrefix(alias, "OSV")),
+        BuildScheme(AliasSchemes.Jvn, alias => alias is not null && Matches(JvnRegex, alias), alias => alias is null ? string.Empty : NormalizePrefix(alias, "JVN")),
+        BuildScheme(AliasSchemes.Jvndb, alias => alias is not null && Matches(JvndbRegex, alias), alias => alias is null ? string.Empty : NormalizePrefix(alias, "JVNDB")),
+        BuildScheme(AliasSchemes.Bdu, alias => alias is not null && Matches(BduRegex, alias), alias => alias is null ? string.Empty : NormalizePrefix(alias, "BDU")),
+        BuildScheme(AliasSchemes.Vu, alias => alias is not null && alias.StartsWith("VU#", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "VU", preserveSeparator: '#')),
+        BuildScheme(AliasSchemes.Msrc, alias => alias is not null && alias.StartsWith("MSRC-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "MSRC")),
+        BuildScheme(AliasSchemes.CiscoSa, alias => alias is not null && alias.StartsWith("CISCO-SA-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "CISCO-SA")),
+        BuildScheme(AliasSchemes.OracleCpu, alias => alias is not null && alias.StartsWith("ORACLE-CPU", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "ORACLE-CPU")),
+        BuildScheme(AliasSchemes.Apsb, alias => alias is not null && alias.StartsWith("APSB-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "APSB")),
+        BuildScheme(AliasSchemes.Apa, alias => alias is not null && alias.StartsWith("APA-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "APA")),
+        BuildScheme(AliasSchemes.AppleHt, alias => alias is not null && alias.StartsWith("APPLE-HT", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "APPLE-HT")),
+        BuildScheme(AliasSchemes.ChromiumPost, alias => alias is not null && (alias.StartsWith("CHROMIUM-POST", StringComparison.OrdinalIgnoreCase) || alias.StartsWith("CHROMIUM:", StringComparison.OrdinalIgnoreCase)), NormalizeChromium),
+        BuildScheme(AliasSchemes.Vmsa, alias => alias is not null && alias.StartsWith("VMSA-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "VMSA")),
+        BuildScheme(AliasSchemes.Rhsa, alias => alias is not null && alias.StartsWith("RHSA-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "RHSA")),
+        BuildScheme(AliasSchemes.Usn, alias => alias is not null && alias.StartsWith("USN-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "USN")),
+        BuildScheme(AliasSchemes.Dsa, alias => alias is not null && alias.StartsWith("DSA-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "DSA")),
+        BuildScheme(AliasSchemes.SuseSu, alias => alias is not null && alias.StartsWith("SUSE-SU-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "SUSE-SU")),
+        BuildScheme(AliasSchemes.Icsa, alias => alias is not null && alias.StartsWith("ICSA-", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "ICSA")),
+        BuildScheme(AliasSchemes.Cwe, alias => alias is not null && Matches(CweRegex, alias), alias => alias is null ? string.Empty : NormalizePrefix(alias, "CWE")),
+        BuildScheme(AliasSchemes.Cpe, alias => alias is not null && alias.StartsWith("cpe:", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "cpe", uppercase:false)),
+        BuildScheme(AliasSchemes.Purl, alias => alias is not null && alias.StartsWith("pkg:", StringComparison.OrdinalIgnoreCase), alias => NormalizePrefix(alias, "pkg", uppercase:false)),
+    };
+
+    private static AliasScheme BuildScheme(string name, Func<string?, bool> predicate, Func<string?, string> normalizer)
+        => new(
+            name,
+            predicate,
+            alias => normalizer(alias));
+
+    private static readonly ImmutableHashSet<string> SchemeNames = SchemeDefinitions
+        .Select(static scheme => scheme.Name)
+        .ToImmutableHashSet(StringComparer.OrdinalIgnoreCase);
+
+    private static readonly Regex CvERegex = new("^CVE-\\d{4}-\\d{4,}$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex GhsaRegex = new("^GHSA-[0-9a-z]{4}-[0-9a-z]{4}-[0-9a-z]{4}$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex OsVRegex = new("^OSV-\\d{4}-\\d+$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex JvnRegex = new("^JVN-\\d{4}-\\d{6}$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex JvndbRegex = new("^JVNDB-\\d{4}-\\d{6}$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex BduRegex = new("^BDU-\\d{4}-\\d+$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+    private static readonly Regex CweRegex = new("^CWE-\\d+$", RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+
+    public static IReadOnlyCollection<string> KnownSchemes => SchemeNames;
+
+    public static bool IsKnownScheme(string? scheme)
+        => !string.IsNullOrWhiteSpace(scheme) && SchemeNames.Contains(scheme);
+
+    public static bool TryGetScheme(string? alias, out string scheme)
+    {
+        if (string.IsNullOrWhiteSpace(alias))
+        {
+            scheme = string.Empty;
+            return false;
+        }
+
+        var candidate = alias.Trim();
+        foreach (var entry in SchemeDefinitions)
+        {
+            if (entry.Predicate(candidate))
+            {
+                scheme = entry.Name;
+                return true;
+            }
+        }
+
+        scheme = string.Empty;
+        return false;
+    }
+
+    public static bool TryNormalize(string? alias, out string normalized, out string scheme)
+    {
+        normalized = string.Empty;
+        scheme = string.Empty;
+
+        if (string.IsNullOrWhiteSpace(alias))
+        {
+            return false;
+        }
+
+        var candidate = alias.Trim();
+        foreach (var entry in SchemeDefinitions)
+        {
+            if (entry.Predicate(candidate))
+            {
+                scheme = entry.Name;
+                normalized = entry.Normalizer(candidate);
+                return true;
+            }
+        }
+
+        normalized = candidate;
+        return false;
+    }
+
+    private static string NormalizePrefix(string? alias, string prefix, bool uppercase = true, char? preserveSeparator = null)
+    {
+        if (string.IsNullOrWhiteSpace(alias))
+        {
+            return string.Empty;
+        }
+
+        var comparison = StringComparison.OrdinalIgnoreCase;
+        if (!alias.StartsWith(prefix, comparison))
+        {
+            return uppercase ? alias : alias.ToLowerInvariant();
+        }
+
+        var remainder = alias[prefix.Length..];
+        if (preserveSeparator is { } separator && remainder.Length > 0 && remainder[0] != separator)
+        {
+            // Edge case: alias is expected to use a specific separator but does not – return unchanged.
+            return uppercase ? prefix.ToUpperInvariant() + remainder : prefix + remainder;
+        }
+
+        var normalizedPrefix = uppercase ? prefix.ToUpperInvariant() : prefix.ToLowerInvariant();
+        return normalizedPrefix + remainder;
+    }
+
+    private static string NormalizeChromium(string? alias)
+    {
+        if (string.IsNullOrWhiteSpace(alias))
+        {
+            return string.Empty;
+        }
+
+        if (alias.StartsWith("CHROMIUM-POST", StringComparison.OrdinalIgnoreCase))
+        {
+            return NormalizePrefix(alias, "CHROMIUM-POST");
+        }
+
+        if (alias.StartsWith("CHROMIUM:", StringComparison.OrdinalIgnoreCase))
+        {
+            var remainder = alias["CHROMIUM".Length..];
+            return "CHROMIUM" + remainder;
+        }
+
+        return alias;
+    }
+    private static bool Matches(Regex? regex, string? candidate)
+    {
+        if (regex is null || string.IsNullOrWhiteSpace(candidate))
+        {
+            return false;
+        }
+
+        return regex.IsMatch(candidate);
+    }
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/AliasSchemes.cs

@@ -0,0 +1,31 @@
+namespace StellaOps.Feedser.Models;
+
+/// <summary>
+/// Well-known alias scheme identifiers referenced throughout the pipeline.
+/// </summary>
+public static class AliasSchemes
+{
+    public const string Cve = "CVE";
+    public const string Ghsa = "GHSA";
+    public const string OsV = "OSV";
+    public const string Jvn = "JVN";
+    public const string Jvndb = "JVNDB";
+    public const string Bdu = "BDU";
+    public const string Vu = "VU";
+    public const string Msrc = "MSRC";
+    public const string CiscoSa = "CISCO-SA";
+    public const string OracleCpu = "ORACLE-CPU";
+    public const string Apsb = "APSB";
+    public const string Apa = "APA";
+    public const string AppleHt = "APPLE-HT";
+    public const string ChromiumPost = "CHROMIUM-POST";
+    public const string Vmsa = "VMSA";
+    public const string Rhsa = "RHSA";
+    public const string Usn = "USN";
+    public const string Dsa = "DSA";
+    public const string SuseSu = "SUSE-SU";
+    public const string Icsa = "ICSA";
+    public const string Cwe = "CWE";
+    public const string Cpe = "CPE";
+    public const string Purl = "PURL";
+}

src/StellaOps.Feedser/StellaOps.Feedser.Models/BACKWARD_COMPATIBILITY.md

@@ -0,0 +1,41 @@
+# Canonical Model Backward-Compatibility Playbook
+
+This playbook captures the policies and workflow required when evolving the canonical
+`StellaOps.Feedser.Models` surface.
+
+## Principles
+
+- **Additive by default** – breaking field removals/renames are not allowed without a staged
+  migration plan.
+- **Version-the-writer** – any change to serialization that affects downstream consumers must bump
+  the exporter version string and update `CANONICAL_RECORDS.md`.
+- **Schema-first** – update documentation (`CANONICAL_RECORDS.md`) and corresponding tests before
+  shipping new fields.
+- **Dual-read period** – when introducing a new field, keep old readers working by:
+  1. Making the field optional in the canonical model.
+  2. Providing default behavior in exporters/mergers when the field is absent.
+  3. Communicating via release notes and toggles when the field will become required.
+
+## Workflow for Changes
+
+1. **Proposal** – raise an issue describing the motivation, affected records, and compatibility
+   impact. Link to the relevant task in `TASKS.md`.
+2. **Docs + Tests first** – update `CANONICAL_RECORDS.md`, add/adjust golden fixtures, and extend
+   regression tests (hash comparisons, snapshot assertions) to capture the new shape.
+3. **Implementation** – introduce the model change along with migration logic (e.g., mergers filling
+   defaults, exporters emitting the new payload).
+4. **Exporter bump** – update exporter version manifests (`ExporterVersion.GetVersion`) whenever the
+   serialized payload differs.
+5. **Announcement** – document the change in release notes, highlighting optional vs. required
+   timelines.
+6. **Cleanup** – once consumers have migrated, remove transitional logic and update docs/tests to
+   reflect the permanent shape.
+
+## Testing Checklist
+
+- `StellaOps.Feedser.Tests.Models` – update unit tests and golden examples.
+- `Serialization determinism` – ensure the hash regression tests cover the new fields.
+- Exporter integration (`Json`, `TrivyDb`) – confirm manifests include provenance + tree metadata
+  for the new shape.
+
+Following this playbook keeps canonical payloads stable while allowing incremental evolution.

src/StellaOps.Feedser/StellaOps.Feedser.Models/CANONICAL_RECORDS.md

@@ -0,0 +1,128 @@
+# Canonical Record Definitions
+
+> Source of truth for the normalized advisory schema emitted by `StellaOps.Feedser.Models`.
+> Keep this document in sync with the public record types under `StellaOps.Feedser.Models` and
+> update it whenever a new field is introduced or semantics change.
+
+## Advisory
+
+| Field | Type | Required | Notes |
+|-------|------|----------|-------|
+| `advisoryKey` | string | yes | Globally unique identifier selected by the merge layer (often a CVE/GHSA/vendor key). Stored lowercased unless vendor casing is significant. |
+| `title` | string | yes | Human readable title. Must be non-empty and trimmed. |
+| `summary` | string? | optional | Short description; trimmed to `null` when empty. |
+| `language` | string? | optional | ISO language code (lowercase). |
+| `published` | DateTimeOffset? | optional | UTC timestamp when vendor originally published. |
+| `modified` | DateTimeOffset? | optional | UTC timestamp when vendor last updated. |
+| `severity` | string? | optional | Normalized severity label (`critical`, `high`, etc.). |
+| `exploitKnown` | bool | yes | Whether KEV/other sources confirm active exploitation. |
+| `aliases` | string[] | yes | Sorted, de-duplicated list of normalized aliases (see [Alias Schemes](#alias-schemes)). |
+| `references` | AdvisoryReference[] | yes | Deterministically ordered reference set. |
+| `affectedPackages` | AffectedPackage[] | yes | Deterministically ordered affected packages. |
+| `cvssMetrics` | CvssMetric[] | yes | Deterministically ordered CVSS metrics (v3, v4 first). |
+| `provenance` | AdvisoryProvenance[] | yes | Normalized provenance entries sorted by source then kind then recorded timestamp. |
+
+### Invariants
+- Collections are immutable (`ImmutableArray<T>`) and always sorted deterministically.
+- `AdvisoryKey` and `Title` are mandatory and trimmed.
+- All timestamps are stored as UTC.
+- Aliases and references leverage helper registries for validation.
+
+## AdvisoryReference
+
+| Field | Type | Required | Notes |
+|-------|------|----------|-------|
+| `url` | string | yes | Absolute HTTP/HTTPS URL. |
+| `kind` | string? | optional | Categorized reference role (e.g. `advisory`, `patch`, `changelog`). |
+| `sourceTag` | string? | optional | Free-form tag identifying originating source. |
+| `summary` | string? | optional | Short description. |
+| `provenance` | AdvisoryProvenance | yes | Provenance entry describing how the reference was mapped. |
+
+Deterministic ordering: by `url`, then `kind`, then `sourceTag`, then `provenance.RecordedAt`.
+
+## AffectedPackage
+
+| Field | Type | Required | Notes |
+|-------|------|----------|-------|
+| `type` | string | yes | Semantic type (`semver`, `rpm`, `deb`, `purl`, `cpe`, etc.). Lowercase. |
+| `identifier` | string | yes | Canonical identifier (package name, PURL, CPE, NEVRA, etc.). |
+| `platform` | string? | optional | Explicit platform / distro (e.g. `ubuntu`, `rhel-8`). |
+| `versionRanges` | AffectedVersionRange[] | yes | Deduplicated + sorted by introduced/fixed/last/expr/kind. |
+| `statuses` | AffectedPackageStatus[] | yes | Optional status flags (e.g. `fixed`, `affected`). |
+| `provenance` | AdvisoryProvenance[] | yes | Provenance entries for package level metadata. |
+
+Deterministic ordering: packages sorted by `type`, then `identifier`, then `platform` (ordinal).
+
+## AffectedVersionRange
+
+| Field | Type | Required | Notes |
+|-------|------|----------|-------|
+| `rangeKind` | string | yes | Classification of range semantics (`semver`, `evr`, `nevra`, `version`, `purl`). Lowercase. |
+| `introducedVersion` | string? | optional | Inclusive lower bound when impact begins. |
+| `fixedVersion` | string? | optional | Exclusive bounding version containing the fix. |
+| `lastAffectedVersion` | string? | optional | Inclusive upper bound when no fix exists. |
+| `rangeExpression` | string? | optional | Normalized textual expression for non-simple ranges. |
+| `provenance` | AdvisoryProvenance | yes | Provenance entry for the range. |
+
+Comparers/equality ignore provenance differences.
+
+## CvssMetric
+
+| Field | Type | Required | Notes |
+|-------|------|----------|-------|
+| `version` | string | yes | `2.0`, `3.0`, `3.1`, `4.0`, etc. |
+| `vector` | string | yes | Official CVSS vector string. |
+| `score` | double | yes | CVSS base score (0.0-10.0). |
+| `severity` | string | yes | Severity label mapped from score or vendor metadata. |
+| `provenance` | AdvisoryProvenance | yes | Provenance entry. |
+
+Sorted by version then vector for determinism.
+
+## AdvisoryProvenance
+
+| Field | Type | Required | Notes |
+|-------|------|----------|-------|
+| `source` | string | yes | Logical source identifier (`nvd`, `redhat`, `osv`, etc.). |
+| `kind` | string | yes | Operation performed (`fetch`, `parse`, `map`, `merge`, `enrich`). |
+| `detail` | string | optional | Free-form pipeline detail (parser identifier, rule set). |
+| `recordedAt` | DateTimeOffset | yes | UTC timestamp when provenance was captured. |
+
+### Provenance Mask Expectations
+Each canonical field is expected to carry at least one provenance entry derived from the
+responsible pipeline stage. When aggregating provenance from subcomponents (e.g., affected package
+ranges), merge code should ensure:
+
+- Advisory level provenance documents the source document and merge actions.
+- References, packages, ranges, and metrics each include their own provenance entry reflecting
+  the most specific source (vendor feed, computed normalization, etc.).
+- Export-specific metadata (digest manifests, offline bundles) include exporter version alongside
+  the builder metadata.
+
+## Alias Schemes
+
+Supported alias scheme prefixes:
+
+- `CVE-`
+- `GHSA-`
+- `OSV-`
+- `JVN-`, `JVNDB-`
+- `BDU-`
+- `VU#`
+- `MSRC-`
+- `CISCO-SA-`
+- `ORACLE-CPU`
+- `APSB-`, `APA-`
+- `APPLE-HT`
+- `CHROMIUM:` / `CHROMIUM-`
+- `VMSA-`
+- `RHSA-`
+- `USN-`
+- `DSA-`
+- `SUSE-SU-`
+- `ICSA-`
+- `CWE-`
+- `cpe:`
+- `pkg:` (Package URL / PURL)
+
+The registry exposed via `AliasSchemes` and `AliasSchemeRegistry` can be used to validate aliases and
+drive downstream conditionals without re-implementing pattern rules.