up

src/Graph/AGENTS.md

@@ -27,8 +27,8 @@
 - Offline posture: no external calls beyond allowlisted feeds; prefer cached schemas and local nugets in `local-nugets/`.
 
 ## Data & Environment
-- Canonical store: MongoDB (>=3.0 driver). Tests use `STELLAOPS_TEST_MONGO_URI`; fallback `mongodb://127.0.0.1:27017`, then Mongo2Go.
-- Collections: `graph_nodes`, `graph_edges`, `graph_overlays_cache`, `graph_snapshots`, `graph_saved_queries`.
+- Storage is currently in-memory (MongoDB dependency removed); persistent backing store to be added in a follow-up sprint.
+- Collections (historical naming) `graph_nodes`, `graph_edges`, `graph_overlays_cache`, `graph_snapshots`, `graph_saved_queries` map to in-memory structures for now.
 - Tenant isolation mandatory on every query and export.
 
 ## Testing Expectations

src/Graph/StellaOps.Graph.Api/AGENTS.md

@@ -23,7 +23,7 @@ Provide tenant-scoped Graph Explorer APIs for search, query, paths, diffs, overl
 
 ## Tooling
 - .NET 10 preview Minimal API with async streaming; pipeline pattern for parsing/planning/fetching.
-- Mongo aggregation / adjacency store from Graph Indexer; optional caching layer.
+- Graph Indexer currently exposes in-memory adjacency storage (Mongo removed); optional caching layer.
 - SSE/WebSockets or chunked NDJSON responses for progressive loading.
 
 ## Definition of Done

src/Graph/StellaOps.Graph.Indexer/AGENTS.md

@@ -5,7 +5,7 @@ Project SBOM, advisory, VEX, and policy overlay data into a tenant-scoped proper
 
 ## Scope
 - Service source under `src/Graph/StellaOps.Graph.Indexer` (workers, ingestion pipelines, schema builders).
-- Mongo collections/object storage for `graph_nodes`, `graph_edges`, `graph_snapshots`, clustering metadata.
+- In-memory graph storage for `graph_nodes`, `graph_edges`, `graph_snapshots`, clustering metadata (Mongo removed; durable store to follow).
 - Event consumers: SBOM ingest, Conseiller advisories, Excitor VEX, Policy overlay materials.
 - Incremental rebuild, diff, and cache warmers for graph overlays.
 
@@ -23,9 +23,9 @@ Project SBOM, advisory, VEX, and policy overlay data into a tenant-scoped proper
 
 ## Tooling
 - .NET 10 preview workers (HostedService + channel pipelines).
-- MongoDB for node/edge storage; S3-compatible buckets for layout tiles/snapshots if needed.
+- In-memory node/edge storage (Mongo removed); S3-compatible buckets for layout tiles/snapshots if needed.
 - Scheduler integration (jobs, change streams) to handle incremental updates.
-- Analytics: clustering/centrality pipelines with Mongo-backed snapshot provider and overlays; change-stream/backfill worker with idempotency store (Mongo or in-memory) and retry/backoff.
+- Analytics: clustering/centrality pipelines with in-memory snapshot provider and overlays; change-stream/backfill worker with in-memory idempotency store and retry/backoff.
 
 ## Definition of Done
 - Pipelines deterministic and tested; fixtures validated.

src/Graph/StellaOps.Graph.Indexer/Analytics/GraphAnalyticsServiceCollectionExtensions.cs

@@ -2,7 +2,6 @@ using System;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
-using MongoDB.Driver;
 
 namespace StellaOps.Graph.Indexer.Analytics;
 
@@ -37,47 +36,4 @@ public static class GraphAnalyticsServiceCollectionExtensions
 
         return services;
     }
-
-    public static IServiceCollection AddGraphAnalyticsMongo(
-        this IServiceCollection services,
-        Action<GraphAnalyticsOptions>? configureOptions = null,
-        Action<MongoGraphSnapshotProviderOptions>? configureSnapshot = null,
-        Action<GraphAnalyticsWriterOptions>? configureWriter = null)
-    {
-        services.AddGraphAnalyticsPipeline(configureOptions);
-
-        if (configureSnapshot is not null)
-        {
-            services.Configure(configureSnapshot);
-        }
-        else
-        {
-            services.Configure<MongoGraphSnapshotProviderOptions>(_ => { });
-        }
-
-        if (configureWriter is not null)
-        {
-            services.Configure(configureWriter);
-        }
-        else
-        {
-            services.Configure<GraphAnalyticsWriterOptions>(_ => { });
-        }
-
-        services.Replace(ServiceDescriptor.Singleton<IGraphSnapshotProvider>(sp =>
-        {
-            var db = sp.GetRequiredService<IMongoDatabase>();
-            var options = sp.GetRequiredService<IOptions<MongoGraphSnapshotProviderOptions>>();
-            return new MongoGraphSnapshotProvider(db, options.Value);
-        }));
-
-        services.Replace(ServiceDescriptor.Singleton<IGraphAnalyticsWriter>(sp =>
-        {
-            var db = sp.GetRequiredService<IMongoDatabase>();
-            var options = sp.GetRequiredService<IOptions<GraphAnalyticsWriterOptions>>();
-            return new MongoGraphAnalyticsWriter(db, options.Value);
-        }));
-
-        return services;
-    }
 }

src/Graph/StellaOps.Graph.Indexer/Analytics/MongoGraphAnalyticsWriter.cs

@@ -1,117 +0,0 @@
-using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.Globalization;
-using System.Linq;
-using System.Text.Json.Nodes;
-using MongoDB.Bson;
-using MongoDB.Driver;
-
-namespace StellaOps.Graph.Indexer.Analytics;
-
-public sealed class MongoGraphAnalyticsWriter : IGraphAnalyticsWriter
-{
-    private readonly IMongoCollection<BsonDocument> _clusters;
-    private readonly IMongoCollection<BsonDocument> _centrality;
-    private readonly IMongoCollection<BsonDocument> _nodes;
-    private readonly GraphAnalyticsWriterOptions _options;
-
-    public MongoGraphAnalyticsWriter(IMongoDatabase database, GraphAnalyticsWriterOptions? options = null)
-    {
-        ArgumentNullException.ThrowIfNull(database);
-
-        _options = options ?? new GraphAnalyticsWriterOptions();
-        _clusters = database.GetCollection<BsonDocument>(_options.ClusterCollectionName);
-        _centrality = database.GetCollection<BsonDocument>(_options.CentralityCollectionName);
-        _nodes = database.GetCollection<BsonDocument>(_options.NodeCollectionName);
-    }
-
-    public async Task PersistClusterAssignmentsAsync(GraphAnalyticsSnapshot snapshot, ImmutableArray<ClusterAssignment> assignments, CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-
-        if (assignments.Length == 0)
-        {
-            return;
-        }
-
-        var models = new List<WriteModel<BsonDocument>>(assignments.Length);
-        foreach (var assignment in assignments)
-        {
-            var filter = Builders<BsonDocument>.Filter.And(
-                Builders<BsonDocument>.Filter.Eq("tenant", snapshot.Tenant),
-                Builders<BsonDocument>.Filter.Eq("snapshot_id", snapshot.SnapshotId),
-                Builders<BsonDocument>.Filter.Eq("node_id", assignment.NodeId));
-
-            var document = new BsonDocument
-            {
-                { "tenant", snapshot.Tenant },
-                { "snapshot_id", snapshot.SnapshotId },
-                { "node_id", assignment.NodeId },
-                { "cluster_id", assignment.ClusterId },
-                { "kind", assignment.Kind },
-                { "generated_at", snapshot.GeneratedAt.UtcDateTime }
-            };
-
-            models.Add(new ReplaceOneModel<BsonDocument>(filter, document) { IsUpsert = true });
-        }
-
-        await _clusters.BulkWriteAsync(models, new BulkWriteOptions { IsOrdered = false }, cancellationToken).ConfigureAwait(false);
-
-        if (_options.WriteClusterAssignmentsToNodes)
-        {
-            await WriteClustersToNodesAsync(assignments, cancellationToken).ConfigureAwait(false);
-        }
-    }
-
-    public async Task PersistCentralityAsync(GraphAnalyticsSnapshot snapshot, ImmutableArray<CentralityScore> scores, CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-
-        if (scores.Length == 0)
-        {
-            return;
-        }
-
-        var models = new List<WriteModel<BsonDocument>>(scores.Length);
-        foreach (var score in scores)
-        {
-            var filter = Builders<BsonDocument>.Filter.And(
-                Builders<BsonDocument>.Filter.Eq("tenant", snapshot.Tenant),
-                Builders<BsonDocument>.Filter.Eq("snapshot_id", snapshot.SnapshotId),
-                Builders<BsonDocument>.Filter.Eq("node_id", score.NodeId));
-
-            var document = new BsonDocument
-            {
-                { "tenant", snapshot.Tenant },
-                { "snapshot_id", snapshot.SnapshotId },
-                { "node_id", score.NodeId },
-                { "kind", score.Kind },
-                { "degree", score.Degree },
-                { "betweenness", score.Betweenness },
-                { "generated_at", snapshot.GeneratedAt.UtcDateTime }
-            };
-
-            models.Add(new ReplaceOneModel<BsonDocument>(filter, document) { IsUpsert = true });
-        }
-
-        await _centrality.BulkWriteAsync(models, new BulkWriteOptions { IsOrdered = false }, cancellationToken).ConfigureAwait(false);
-    }
-
-    private async Task WriteClustersToNodesAsync(IEnumerable<ClusterAssignment> assignments, CancellationToken cancellationToken)
-    {
-        var models = new List<WriteModel<BsonDocument>>();
-        foreach (var assignment in assignments)
-        {
-            var filter = Builders<BsonDocument>.Filter.Eq("id", assignment.NodeId);
-            var update = Builders<BsonDocument>.Update.Set("attributes.cluster_id", assignment.ClusterId);
-            models.Add(new UpdateOneModel<BsonDocument>(filter, update) { IsUpsert = false });
-        }
-
-        if (models.Count == 0)
-        {
-            return;
-        }
-
-        await _nodes.BulkWriteAsync(models, new BulkWriteOptions { IsOrdered = false }, cancellationToken).ConfigureAwait(false);
-    }
-}

src/Graph/StellaOps.Graph.Indexer/Analytics/MongoGraphSnapshotProvider.cs

@@ -1,79 +0,0 @@
-using System.Collections.Immutable;
-using System.Text.Json.Nodes;
-using MongoDB.Bson;
-using MongoDB.Driver;
-using StellaOps.Graph.Indexer.Infrastructure;
-
-namespace StellaOps.Graph.Indexer.Analytics;
-
-public sealed class MongoGraphSnapshotProvider : IGraphSnapshotProvider
-{
-    private readonly IMongoCollection<BsonDocument> _snapshots;
-    private readonly IMongoCollection<BsonDocument> _progress;
-    private readonly MongoGraphSnapshotProviderOptions _options;
-
-    public MongoGraphSnapshotProvider(IMongoDatabase database, MongoGraphSnapshotProviderOptions? options = null)
-    {
-        ArgumentNullException.ThrowIfNull(database);
-        _options = options ?? new MongoGraphSnapshotProviderOptions();
-        _snapshots = database.GetCollection<BsonDocument>(_options.SnapshotCollectionName);
-        _progress = database.GetCollection<BsonDocument>(_options.ProgressCollectionName);
-    }
-
-    public async Task<IReadOnlyList<GraphAnalyticsSnapshot>> GetPendingSnapshotsAsync(CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-
-        var processedIds = await _progress
-            .Find(FilterDefinition<BsonDocument>.Empty)
-            .Project(doc => doc["snapshot_id"].AsString)
-            .ToListAsync(cancellationToken)
-            .ConfigureAwait(false);
-
-        var filter = Builders<BsonDocument>.Filter.Nin("snapshot_id", processedIds);
-        var snapshots = await _snapshots
-            .Find(filter)
-            .Limit(_options.MaxBatch)
-            .Sort(Builders<BsonDocument>.Sort.Descending("generated_at"))
-            .ToListAsync(cancellationToken)
-            .ConfigureAwait(false);
-
-        var result = new List<GraphAnalyticsSnapshot>(snapshots.Count);
-        foreach (var snapshot in snapshots)
-        {
-            var tenant = snapshot.GetValue("tenant", string.Empty).AsString;
-            var snapshotId = snapshot.GetValue("snapshot_id", string.Empty).AsString;
-            var generatedAt = snapshot.TryGetValue("generated_at", out var generated)
-                              && generated.BsonType == BsonType.DateTime
-                ? DateTime.SpecifyKind(generated.ToUniversalTime(), DateTimeKind.Utc)
-                : DateTimeOffset.UtcNow;
-
-            var nodes = snapshot.TryGetValue("nodes", out var nodesValue) && nodesValue is BsonArray nodesArray
-                ? BsonJsonConverter.ToJsonArray(nodesArray).Select(n => (JsonObject)n!).ToImmutableArray()
-                : ImmutableArray<JsonObject>.Empty;
-
-            var edges = snapshot.TryGetValue("edges", out var edgesValue) && edgesValue is BsonArray edgesArray
-                ? BsonJsonConverter.ToJsonArray(edgesArray).Select(n => (JsonObject)n!).ToImmutableArray()
-                : ImmutableArray<JsonObject>.Empty;
-
-            result.Add(new GraphAnalyticsSnapshot(tenant, snapshotId, generatedAt, nodes, edges));
-        }
-
-        return result;
-    }
-
-    public async Task MarkProcessedAsync(string tenant, string snapshotId, CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-
-        var filter = Builders<BsonDocument>.Filter.Eq("snapshot_id", snapshotId)
-                     & Builders<BsonDocument>.Filter.Eq("tenant", tenant);
-
-        var update = Builders<BsonDocument>.Update.Set("snapshot_id", snapshotId)
-            .Set("tenant", tenant)
-            .SetOnInsert("processed_at", DateTimeOffset.UtcNow.UtcDateTime);
-
-        await _progress.UpdateOneAsync(filter, update, new UpdateOptions { IsUpsert = true }, cancellationToken)
-            .ConfigureAwait(false);
-    }
-}

src/Graph/StellaOps.Graph.Indexer/Analytics/MongoGraphSnapshotProviderOptions.cs

@@ -1,8 +0,0 @@
-namespace StellaOps.Graph.Indexer.Analytics;
-
-public sealed class MongoGraphSnapshotProviderOptions
-{
-    public string SnapshotCollectionName { get; set; } = "graph_snapshots";
-    public string ProgressCollectionName { get; set; } = "graph_analytics_progress";
-    public int MaxBatch { get; set; } = 5;
-}

src/Graph/StellaOps.Graph.Indexer/Incremental/GraphChangeStreamServiceCollectionExtensions.cs

@@ -1,8 +1,7 @@
 using System;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
-using Microsoft.Extensions.Options;
-using MongoDB.Driver;
+using StellaOps.Graph.Indexer.Ingestion.Sbom;
 
 namespace StellaOps.Graph.Indexer.Incremental;
 
@@ -23,58 +22,12 @@ public static class GraphChangeStreamServiceCollectionExtensions
             services.Configure<GraphChangeStreamOptions>(_ => { });
         }
 
+        services.TryAddSingleton<IGraphChangeEventSource, NoOpGraphChangeEventSource>();
+        services.TryAddSingleton<IGraphBackfillSource, NoOpGraphChangeEventSource>();
+        services.TryAddSingleton<IIdempotencyStore, InMemoryIdempotencyStore>();
+        services.TryAddSingleton<IGraphDocumentWriter, InMemoryGraphDocumentWriter>();
         services.AddSingleton<GraphBackfillMetrics>();
         services.AddHostedService<GraphChangeStreamProcessor>();
         return services;
     }
-
-    public static IServiceCollection AddGraphChangeStreamProcessorWithMongo(
-        this IServiceCollection services,
-        Action<GraphChangeStreamOptions>? configureOptions = null,
-        Action<MongoGraphChangeEventOptions>? configureChangeOptions = null,
-        Action<MongoIdempotencyStoreOptions>? configureIdempotency = null)
-    {
-        services.AddGraphChangeStreamProcessor(configureOptions);
-
-        if (configureChangeOptions is not null)
-        {
-            services.Configure(configureChangeOptions);
-        }
-        else
-        {
-            services.Configure<MongoGraphChangeEventOptions>(_ => { });
-        }
-
-        if (configureIdempotency is not null)
-        {
-            services.Configure(configureIdempotency);
-        }
-        else
-        {
-            services.Configure<MongoIdempotencyStoreOptions>(_ => { });
-        }
-
-        services.Replace(ServiceDescriptor.Singleton<IGraphChangeEventSource>(sp =>
-        {
-            var db = sp.GetRequiredService<IMongoDatabase>();
-            var opts = sp.GetRequiredService<IOptions<MongoGraphChangeEventOptions>>();
-            return new MongoGraphChangeEventSource(db, opts.Value);
-        }));
-
-        services.Replace(ServiceDescriptor.Singleton<IGraphBackfillSource>(sp =>
-        {
-            var db = sp.GetRequiredService<IMongoDatabase>();
-            var opts = sp.GetRequiredService<IOptions<MongoGraphChangeEventOptions>>();
-            return new MongoGraphChangeEventSource(db, opts.Value);
-        }));
-
-        services.Replace(ServiceDescriptor.Singleton<IIdempotencyStore>(sp =>
-        {
-            var db = sp.GetRequiredService<IMongoDatabase>();
-            var opts = sp.GetRequiredService<IOptions<MongoIdempotencyStoreOptions>>();
-            return new MongoIdempotencyStore(db, opts.Value);
-        }));
-
-        return services;
-    }
 }

src/Graph/StellaOps.Graph.Indexer/Incremental/MongoGraphChangeEventOptions.cs

@@ -1,10 +0,0 @@
-namespace StellaOps.Graph.Indexer.Incremental;
-
-public sealed class MongoGraphChangeEventOptions
-{
-    public string CollectionName { get; set; } = "graph_change_events";
-    public string SequenceFieldName { get; set; } = "sequence_token";
-    public string NodeArrayFieldName { get; set; } = "nodes";
-    public string EdgeArrayFieldName { get; set; } = "edges";
-    public int MaxBatchSize { get; set; } = 256;
-}

src/Graph/StellaOps.Graph.Indexer/Incremental/MongoGraphChangeEventSource.cs

@@ -1,72 +0,0 @@
-using System.Collections.Immutable;
-using System.Text.Json.Nodes;
-using MongoDB.Bson;
-using MongoDB.Driver;
-using StellaOps.Graph.Indexer.Infrastructure;
-
-namespace StellaOps.Graph.Indexer.Incremental;
-
-public sealed class MongoGraphChangeEventSource : IGraphChangeEventSource, IGraphBackfillSource
-{
-    private readonly IMongoCollection<BsonDocument> _collection;
-    private readonly MongoGraphChangeEventOptions _options;
-
-    public MongoGraphChangeEventSource(IMongoDatabase database, MongoGraphChangeEventOptions? options = null)
-    {
-        ArgumentNullException.ThrowIfNull(database);
-        _options = options ?? new MongoGraphChangeEventOptions();
-        _collection = database.GetCollection<BsonDocument>(_options.CollectionName);
-    }
-
-    public async IAsyncEnumerable<GraphChangeEvent> ReadAsync([System.Runtime.CompilerServices.EnumeratorCancellation] CancellationToken cancellationToken)
-    {
-        var filter = Builders<BsonDocument>.Filter.Eq("is_backfill", false);
-        await foreach (var change in EnumerateAsync(filter, cancellationToken))
-        {
-            yield return change with { IsBackfill = false };
-        }
-    }
-
-    public async IAsyncEnumerable<GraphChangeEvent> ReadBackfillAsync([System.Runtime.CompilerServices.EnumeratorCancellation] CancellationToken cancellationToken)
-    {
-        var filter = Builders<BsonDocument>.Filter.Eq("is_backfill", true);
-        await foreach (var change in EnumerateAsync(filter, cancellationToken))
-        {
-            yield return change with { IsBackfill = true };
-        }
-    }
-
-    private async IAsyncEnumerable<GraphChangeEvent> EnumerateAsync(FilterDefinition<BsonDocument> filter, [System.Runtime.CompilerServices.EnumeratorCancellation] CancellationToken cancellationToken)
-    {
-        var sort = Builders<BsonDocument>.Sort.Ascending(_options.SequenceFieldName);
-        using var cursor = await _collection.FindAsync(filter, new FindOptions<BsonDocument> { Sort = sort, BatchSize = _options.MaxBatchSize }, cancellationToken).ConfigureAwait(false);
-
-        while (await cursor.MoveNextAsync(cancellationToken).ConfigureAwait(false))
-        {
-            foreach (var doc in cursor.Current)
-            {
-                cancellationToken.ThrowIfCancellationRequested();
-
-                var tenant = doc.GetValue("tenant", string.Empty).AsString;
-                var snapshotId = doc.GetValue("snapshot_id", string.Empty).AsString;
-                var sequence = doc.GetValue(_options.SequenceFieldName, string.Empty).AsString;
-
-                var nodes = doc.TryGetValue(_options.NodeArrayFieldName, out var nodesValue) && nodesValue is BsonArray nodeArray
-                    ? BsonJsonConverter.ToJsonArray(nodeArray).Select(n => (JsonObject)n!).ToImmutableArray()
-                    : ImmutableArray<JsonObject>.Empty;
-
-                var edges = doc.TryGetValue(_options.EdgeArrayFieldName, out var edgesValue) && edgesValue is BsonArray edgeArray
-                    ? BsonJsonConverter.ToJsonArray(edgeArray).Select(n => (JsonObject)n!).ToImmutableArray()
-                    : ImmutableArray<JsonObject>.Empty;
-
-                yield return new GraphChangeEvent(
-                    tenant,
-                    snapshotId,
-                    sequence,
-                    nodes,
-                    edges,
-                    doc.GetValue("is_backfill", false).ToBoolean());
-            }
-        }
-    }
-}

src/Graph/StellaOps.Graph.Indexer/Incremental/MongoIdempotencyStore.cs

@@ -1,34 +0,0 @@
-using MongoDB.Bson;
-using MongoDB.Driver;
-
-namespace StellaOps.Graph.Indexer.Incremental;
-
-public sealed class MongoIdempotencyStore : IIdempotencyStore
-{
-    private readonly IMongoCollection<BsonDocument> _collection;
-
-    public MongoIdempotencyStore(IMongoDatabase database, MongoIdempotencyStoreOptions? options = null)
-    {
-        ArgumentNullException.ThrowIfNull(database);
-        var resolved = options ?? new MongoIdempotencyStoreOptions();
-        _collection = database.GetCollection<BsonDocument>(resolved.CollectionName);
-    }
-
-    public async Task<bool> HasSeenAsync(string sequenceToken, CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        var filter = Builders<BsonDocument>.Filter.Eq("sequence_token", sequenceToken);
-        return await _collection.Find(filter).AnyAsync(cancellationToken).ConfigureAwait(false);
-    }
-
-    public async Task MarkSeenAsync(string sequenceToken, CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        var filter = Builders<BsonDocument>.Filter.Eq("sequence_token", sequenceToken);
-        var update = Builders<BsonDocument>.Update.Set("sequence_token", sequenceToken)
-            .SetOnInsert("recorded_at", DateTimeOffset.UtcNow.UtcDateTime);
-
-        await _collection.UpdateOneAsync(filter, update, new UpdateOptions { IsUpsert = true }, cancellationToken)
-            .ConfigureAwait(false);
-    }
-}

src/Graph/StellaOps.Graph.Indexer/Incremental/MongoIdempotencyStoreOptions.cs

@@ -1,6 +0,0 @@
-namespace StellaOps.Graph.Indexer.Incremental;
-
-public sealed class MongoIdempotencyStoreOptions
-{
-    public string CollectionName { get; set; } = "graph_change_idempotency";
-}

src/Graph/StellaOps.Graph.Indexer/Incremental/NoOpGraphChangeEventSource.cs

@@ -0,0 +1,23 @@
+using System.Collections.Immutable;
+using System.Runtime.CompilerServices;
+using System.Text.Json.Nodes;
+
+namespace StellaOps.Graph.Indexer.Incremental;
+
+/// <summary>
+/// No-op change/backfill source used when no external change feed is configured.
+/// </summary>
+public sealed class NoOpGraphChangeEventSource : IGraphChangeEventSource, IGraphBackfillSource
+{
+    public IAsyncEnumerable<GraphChangeEvent> ReadAsync(CancellationToken cancellationToken) =>
+        ReadInternalAsync(cancellationToken);
+
+    public IAsyncEnumerable<GraphChangeEvent> ReadBackfillAsync(CancellationToken cancellationToken) =>
+        ReadInternalAsync(cancellationToken);
+
+    private static async IAsyncEnumerable<GraphChangeEvent> ReadInternalAsync([EnumeratorCancellation] CancellationToken cancellationToken)
+    {
+        await Task.CompletedTask.ConfigureAwait(false);
+        yield break;
+    }
+}

src/Graph/StellaOps.Graph.Indexer/Infrastructure/BsonJsonConverter.cs

@@ -1,21 +0,0 @@
-using System.Text.Json.Nodes;
-using MongoDB.Bson;
-
-namespace StellaOps.Graph.Indexer.Infrastructure;
-
-internal static class BsonJsonConverter
-{
-    public static JsonObject ToJsonObject(BsonDocument document)
-    {
-        ArgumentNullException.ThrowIfNull(document);
-        var parsed = JsonNode.Parse(document.ToJson());
-        return parsed as JsonObject ?? new JsonObject();
-    }
-
-    public static JsonArray ToJsonArray(BsonArray array)
-    {
-        ArgumentNullException.ThrowIfNull(array);
-        var parsed = JsonNode.Parse(array.ToJson());
-        return parsed as JsonArray ?? new JsonArray();
-    }
-}

src/Graph/StellaOps.Graph.Indexer/Infrastructure/MongoDatabaseOptions.cs

@@ -1,7 +0,0 @@
-namespace StellaOps.Graph.Indexer.Infrastructure;
-
-public sealed class MongoDatabaseOptions
-{
-    public string ConnectionString { get; set; } = string.Empty;
-    public string DatabaseName { get; set; } = "stellaops-graph";
-}

src/Graph/StellaOps.Graph.Indexer/Infrastructure/MongoServiceCollectionExtensions.cs

@@ -1,48 +0,0 @@
-using System;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Options;
-using MongoDB.Driver;
-
-namespace StellaOps.Graph.Indexer.Infrastructure;
-
-public static class MongoServiceCollectionExtensions
-{
-    public static IServiceCollection AddGraphMongoDatabase(
-        this IServiceCollection services,
-        Action<MongoDatabaseOptions> configure)
-    {
-        ArgumentNullException.ThrowIfNull(services);
-        ArgumentNullException.ThrowIfNull(configure);
-
-        services.Configure(configure);
-
-        services.AddSingleton<IMongoClient>(sp =>
-        {
-            var opts = sp.GetRequiredService<IOptions<MongoDatabaseOptions>>().Value;
-            Validate(opts);
-            return new MongoClient(opts.ConnectionString);
-        });
-
-        services.AddSingleton<IMongoDatabase>(sp =>
-        {
-            var opts = sp.GetRequiredService<IOptions<MongoDatabaseOptions>>().Value;
-            Validate(opts);
-            return sp.GetRequiredService<IMongoClient>().GetDatabase(opts.DatabaseName);
-        });
-
-        return services;
-    }
-
-    private static void Validate(MongoDatabaseOptions options)
-    {
-        if (string.IsNullOrWhiteSpace(options.ConnectionString))
-        {
-            throw new InvalidOperationException("Mongo connection string must be provided.");
-        }
-
-        if (string.IsNullOrWhiteSpace(options.DatabaseName))
-        {
-            throw new InvalidOperationException("Mongo database name must be provided.");
-        }
-    }
-}

src/Graph/StellaOps.Graph.Indexer/Ingestion/Advisory/MongoGraphDocumentWriter.cs

@@ -1,84 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text.Encodings.Web;
-using System.Text.Json;
-using System.Text.Json.Nodes;
-using StellaOps.Graph.Indexer.Ingestion.Sbom;
-using System.Threading;
-using System.Threading.Tasks;
-using MongoDB.Bson;
-using MongoDB.Driver;
-
-namespace StellaOps.Graph.Indexer.Ingestion.Advisory;
-
-public sealed class MongoGraphDocumentWriter : IGraphDocumentWriter
-{
-    private static readonly JsonSerializerOptions SerializerOptions = new()
-    {
-        Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
-        WriteIndented = false
-    };
-
-    private readonly IMongoCollection<BsonDocument> _nodes;
-    private readonly IMongoCollection<BsonDocument> _edges;
-
-    public MongoGraphDocumentWriter(IMongoDatabase database, MongoGraphDocumentWriterOptions? options = null)
-    {
-        ArgumentNullException.ThrowIfNull(database);
-
-        var resolved = options ?? new MongoGraphDocumentWriterOptions();
-        _nodes = database.GetCollection<BsonDocument>(resolved.NodeCollectionName);
-        _edges = database.GetCollection<BsonDocument>(resolved.EdgeCollectionName);
-    }
-
-    public async Task WriteAsync(GraphBuildBatch batch, CancellationToken cancellationToken)
-    {
-        ArgumentNullException.ThrowIfNull(batch);
-        cancellationToken.ThrowIfCancellationRequested();
-
-        if (batch.Nodes.Length > 0)
-        {
-            var nodeModels = CreateReplaceModels(_nodes, batch.Nodes);
-            if (nodeModels.Count > 0)
-            {
-                await _nodes.BulkWriteAsync(nodeModels, new BulkWriteOptions { IsOrdered = false }, cancellationToken)
-                    .ConfigureAwait(false);
-            }
-        }
-
-        if (batch.Edges.Length > 0)
-        {
-            var edgeModels = CreateReplaceModels(_edges, batch.Edges);
-            if (edgeModels.Count > 0)
-            {
-                await _edges.BulkWriteAsync(edgeModels, new BulkWriteOptions { IsOrdered = false }, cancellationToken)
-                    .ConfigureAwait(false);
-            }
-        }
-    }
-
-    private static List<WriteModel<BsonDocument>> CreateReplaceModels(IMongoCollection<BsonDocument> collection, IReadOnlyList<JsonObject> documents)
-    {
-        var models = new List<WriteModel<BsonDocument>>(documents.Count);
-        foreach (var document in documents)
-        {
-            if (!document.TryGetPropertyValue("id", out var idNode) || idNode is null)
-            {
-                continue;
-            }
-
-            var id = idNode.GetValue<string>();
-            var filter = Builders<BsonDocument>.Filter.Eq("id", id);
-            var bsonDocument = ToBsonDocument(document);
-            models.Add(new ReplaceOneModel<BsonDocument>(filter, bsonDocument) { IsUpsert = true });
-        }
-
-        return models;
-    }
-
-    private static BsonDocument ToBsonDocument(JsonObject json)
-    {
-        var jsonString = json.ToJsonString(SerializerOptions);
-        return BsonDocument.Parse(jsonString);
-    }
-}

src/Graph/StellaOps.Graph.Indexer/Ingestion/Advisory/MongoGraphDocumentWriterOptions.cs

@@ -1,7 +0,0 @@
-namespace StellaOps.Graph.Indexer.Ingestion.Advisory;
-
-public sealed class MongoGraphDocumentWriterOptions
-{
-    public string NodeCollectionName { get; init; } = "graph_nodes";
-    public string EdgeCollectionName { get; init; } = "graph_edges";
-}

src/Graph/StellaOps.Graph.Indexer/Ingestion/Inspector/InspectorIngestServiceCollectionExtensions.cs

@@ -11,6 +11,7 @@ public static class InspectorIngestServiceCollectionExtensions
     {
         ArgumentNullException.ThrowIfNull(services);
 
+        services.TryAddSingleton<Ingestion.Sbom.IGraphDocumentWriter, Ingestion.Sbom.InMemoryGraphDocumentWriter>();
         services.TryAddSingleton<GraphInspectorTransformer>();
         services.TryAddSingleton<GraphInspectorProcessor>(provider =>
         {

src/Graph/StellaOps.Graph.Indexer/Ingestion/Sbom/InMemoryGraphDocumentWriter.cs

@@ -0,0 +1,30 @@
+using System.Collections.Concurrent;
+using System.Collections.Immutable;
+using System.Text.Json.Nodes;
+
+namespace StellaOps.Graph.Indexer.Ingestion.Sbom;
+
+/// <summary>
+/// In-memory graph document writer used as a Mongo-free fallback.
+/// </summary>
+public sealed class InMemoryGraphDocumentWriter : IGraphDocumentWriter
+{
+    private readonly ConcurrentBag<GraphBuildBatch> _batches = new();
+
+    public IReadOnlyCollection<GraphBuildBatch> Batches => _batches.ToArray();
+
+    public Task WriteAsync(GraphBuildBatch batch, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(batch);
+        _batches.Add(CloneBatch(batch));
+        return Task.CompletedTask;
+    }
+
+    private static GraphBuildBatch CloneBatch(GraphBuildBatch source)
+    {
+        static JsonObject CloneNode(JsonObject node) => (JsonObject)node.DeepClone();
+        return new GraphBuildBatch(
+            ImmutableArray.CreateRange(source.Nodes.Select(CloneNode)),
+            ImmutableArray.CreateRange(source.Edges.Select(CloneNode)));
+    }
+}

src/Graph/StellaOps.Graph.Indexer/Ingestion/Sbom/SbomIngestServiceCollectionExtensions.cs

@@ -22,6 +22,7 @@ public static class SbomIngestServiceCollectionExtensions
             services.Configure(configure);
         }
 
+        services.TryAddSingleton<IGraphDocumentWriter, InMemoryGraphDocumentWriter>();
         services.TryAddSingleton<SbomIngestTransformer>();
         services.TryAddSingleton<ISbomIngestMetrics, SbomIngestMetrics>();
 

src/Graph/StellaOps.Graph.Indexer/StellaOps.Graph.Indexer.csproj

@@ -13,8 +13,6 @@
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.0" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="10.0.0" />
-    <PackageReference Include="MongoDB.Driver" Version="3.5.0" />
-    <PackageReference Include="MongoDB.Bson" Version="3.5.0" />
     <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="10.0.0" />
   </ItemGroup>
 </Project>

src/Graph/__Tests/StellaOps.Graph.Indexer.Tests/MongoProviderIntegrationTests.cs

@@ -1,125 +0,0 @@
-using System.Collections.Immutable;
-using System.Text.Json.Nodes;
-using Mongo2Go;
-using MongoDB.Bson;
-using MongoDB.Driver;
-using StellaOps.Graph.Indexer.Analytics;
-using StellaOps.Graph.Indexer.Incremental;
-
-namespace StellaOps.Graph.Indexer.Tests;
-
-public sealed class MongoProviderIntegrationTests : IAsyncLifetime
-{
-    private readonly MongoDbRunner _runner;
-    private IMongoDatabase _database = default!;
-
-    public MongoProviderIntegrationTests()
-    {
-        _runner = MongoDbRunner.Start(singleNodeReplSet: true);
-    }
-
-    public Task InitializeAsync()
-    {
-        var client = new MongoClient(_runner.ConnectionString);
-        _database = client.GetDatabase("graph-indexer-tests");
-        return Task.CompletedTask;
-    }
-
-    public Task DisposeAsync()
-    {
-        _runner.Dispose();
-        return Task.CompletedTask;
-    }
-
-    [Fact]
-    public async Task SnapshotProvider_ReadsPendingSnapshots()
-    {
-        var snapshots = _database.GetCollection<BsonDocument>("graph_snapshots");
-        var nodes = new BsonArray
-        {
-            new BsonDocument
-            {
-                { "id", "gn:tenant-a:component:1" },
-                { "kind", "component" },
-                { "attributes", new BsonDocument { { "purl", "pkg:npm/a@1.0.0" } } }
-            }
-        };
-
-        var edges = new BsonArray();
-
-        await snapshots.InsertOneAsync(new BsonDocument
-        {
-            { "tenant", "tenant-a" },
-            { "snapshot_id", "snap-1" },
-            { "generated_at", DateTime.UtcNow },
-            { "nodes", nodes },
-            { "edges", edges }
-        });
-
-        var provider = new MongoGraphSnapshotProvider(_database);
-        var pending = await provider.GetPendingSnapshotsAsync(CancellationToken.None);
-
-        Assert.Single(pending);
-        Assert.Equal("snap-1", pending[0].SnapshotId);
-        Assert.Single(pending[0].Nodes);
-
-        await provider.MarkProcessedAsync("tenant-a", "snap-1", CancellationToken.None);
-        var none = await provider.GetPendingSnapshotsAsync(CancellationToken.None);
-        Assert.Empty(none);
-    }
-
-    [Fact]
-    public async Task ChangeEventSource_EnumeratesAndHonorsIdempotency()
-    {
-        var changes = _database.GetCollection<BsonDocument>("graph_change_events");
-        await changes.InsertManyAsync(new[]
-        {
-            new BsonDocument
-            {
-                { "tenant", "tenant-a" },
-                { "snapshot_id", "snap-1" },
-                { "sequence_token", "seq-1" },
-                { "is_backfill", false },
-                { "nodes", new BsonArray { new BsonDocument { { "id", "gn:1" }, { "kind", "component" } } } },
-                { "edges", new BsonArray() }
-            },
-            new BsonDocument
-            {
-                { "tenant", "tenant-a" },
-                { "snapshot_id", "snap-1" },
-                { "sequence_token", "seq-2" },
-                { "is_backfill", false },
-                { "nodes", new BsonArray { new BsonDocument { { "id", "gn:2" }, { "kind", "component" } } } },
-                { "edges", new BsonArray() }
-            }
-        });
-
-        var source = new MongoGraphChangeEventSource(_database);
-        var idempotency = new MongoIdempotencyStore(_database);
-
-        var events = new List<GraphChangeEvent>();
-        await foreach (var change in source.ReadAsync(CancellationToken.None))
-        {
-            if (await idempotency.HasSeenAsync(change.SequenceToken, CancellationToken.None))
-            {
-                continue;
-            }
-
-            events.Add(change);
-            await idempotency.MarkSeenAsync(change.SequenceToken, CancellationToken.None);
-        }
-
-        Assert.Equal(2, events.Count);
-
-        var secondPass = new List<GraphChangeEvent>();
-        await foreach (var change in source.ReadAsync(CancellationToken.None))
-        {
-            if (!await idempotency.HasSeenAsync(change.SequenceToken, CancellationToken.None))
-            {
-                secondPass.Add(change);
-            }
-        }
-
-        Assert.Empty(secondPass);
-    }
-}

src/Graph/__Tests/StellaOps.Graph.Indexer.Tests/MongoServiceCollectionExtensionsTests.cs

@@ -1,44 +0,0 @@
-using Microsoft.Extensions.DependencyInjection;
-using StellaOps.Graph.Indexer.Infrastructure;
-using Mongo2Go;
-using MongoDB.Driver;
-
-namespace StellaOps.Graph.Indexer.Tests;
-
-public sealed class MongoServiceCollectionExtensionsTests : IAsyncLifetime
-{
-    private MongoDbRunner _runner = default!;
-
-    public Task InitializeAsync()
-    {
-        _runner = MongoDbRunner.Start(singleNodeReplSet: true);
-        return Task.CompletedTask;
-    }
-
-    public Task DisposeAsync()
-    {
-        _runner.Dispose();
-        return Task.CompletedTask;
-    }
-
-    [Fact]
-    public void AddGraphMongoDatabase_RegistersClientAndDatabase()
-    {
-        var services = new ServiceCollection();
-
-        services.AddGraphMongoDatabase(options =>
-        {
-            options.ConnectionString = _runner.ConnectionString;
-            options.DatabaseName = "graph-indexer-ext-tests";
-        });
-
-        var provider = services.BuildServiceProvider();
-
-        var client = provider.GetService<IMongoClient>();
-        var database = provider.GetService<IMongoDatabase>();
-
-        Assert.NotNull(client);
-        Assert.NotNull(database);
-        Assert.Equal("graph-indexer-ext-tests", database!.DatabaseNamespace.DatabaseName);
-    }
-}

src/Graph/__Tests/StellaOps.Graph.Indexer.Tests/StellaOps.Graph.Indexer.Tests.csproj

@@ -12,6 +12,5 @@
     <PackageReference Include="xunit" Version="2.9.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
-    <PackageReference Include="Mongo2Go" Version="3.1.3" />
   </ItemGroup>
 </Project>