up

src/Scanner/StellaOps.Scanner.Worker/Determinism/DeterminismContext.cs

@@ -16,6 +16,8 @@ public sealed class DeterminismContext
         ConcurrencyLimit = concurrencyLimit;
     }
 
+    public bool IsDeterminismEnabled => FixedClock || RngSeed.HasValue || ConcurrencyLimit.HasValue || FilterLogs;
+
     public bool FixedClock { get; }
 
     public DateTimeOffset FixedInstantUtc { get; }

src/Scanner/StellaOps.Scanner.Worker/Processing/Surface/SurfaceManifestStageExecutor.cs

@@ -74,6 +74,12 @@ internal sealed class SurfaceManifestStageExecutor : IScanStageExecutor
 
         var payloads = CollectPayloads(context);
         await PersistRubyPackagesAsync(context, cancellationToken).ConfigureAwait(false);
+
+        var determinismPayload = BuildDeterminismPayload(context, payloads, out var merkleRoot);
+        if (determinismPayload is not null)
+        {
+            payloads.Add(determinismPayload);
+        }
         if (payloads.Count == 0)
         {
             _metrics.RecordSurfaceManifestSkipped(context);
@@ -96,7 +102,12 @@ internal sealed class SurfaceManifestStageExecutor : IScanStageExecutor
                 Payloads: payloads,
                 Component: "scanner.worker",
                 Version: _componentVersion,
-                WorkerInstance: Environment.MachineName);
+                WorkerInstance: Environment.MachineName,
+                DeterminismMerkleRoot: merkleRoot,
+                ReplayBundleUri: GetReplayBundleUri(context),
+                ReplayBundleHash: GetReplayBundleHash(context),
+                ReplayPolicyPin: GetPin(context, "determinism.policy"),
+                ReplayFeedPin: GetPin(context, "determinism.feed"));
 
             var result = await _publisher.PublishAsync(request, cancellationToken).ConfigureAwait(false);
 
@@ -233,8 +244,9 @@ internal sealed class SurfaceManifestStageExecutor : IScanStageExecutor
         return payloads;
     }
 
-    private SurfaceManifestPayload? BuildDeterminismPayload(ScanJobContext context, IEnumerable<SurfaceManifestPayload> payloads)
+    private SurfaceManifestPayload? BuildDeterminismPayload(ScanJobContext context, IEnumerable<SurfaceManifestPayload> payloads, out string? merkleRoot)
     {
+        merkleRoot = null;
         var pins = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
         if (context.Lease.Metadata.TryGetValue("determinism.feed", out var feed) && !string.IsNullOrWhiteSpace(feed))
         {
@@ -246,12 +258,8 @@ internal sealed class SurfaceManifestStageExecutor : IScanStageExecutor
             pins["policy"] = policy;
         }
 
-        var artifactHashes = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
-        foreach (var payload in payloads)
-        {
-            var digest = ComputeDigest(payload.Content.Span);
-            artifactHashes[payload.Kind] = digest;
-        }
+        var (artifactHashes, merkle) = ComputeDeterminismHashes(payloads);
+        merkleRoot = merkle;
 
         var report = new
         {
@@ -261,9 +269,13 @@ internal sealed class SurfaceManifestStageExecutor : IScanStageExecutor
             filterLogs = _determinism.FilterLogs,
             concurrencyLimit = _determinism.ConcurrencyLimit,
             pins = pins,
-            artifacts = artifactHashes
+            artifacts = artifactHashes,
+            merkleRoot = merkle
         };
 
+        var evidence = new Determinism.DeterminismEvidence(artifactHashes, merkle);
+        context.Analysis.Set(ScanAnalysisKeys.DeterminismEvidence, evidence);
+
         var json = JsonSerializer.Serialize(report, JsonOptions);
         return new SurfaceManifestPayload(
             ArtifactDocumentType.SurfaceObservation,
@@ -274,6 +286,46 @@ internal sealed class SurfaceManifestStageExecutor : IScanStageExecutor
             View: "replay");
     }
 
+    private static (Dictionary<string, string> Hashes, string MerkleRoot) ComputeDeterminismHashes(IEnumerable<SurfaceManifestPayload> payloads)
+    {
+        var map = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        using var sha = SHA256.Create();
+
+        foreach (var payload in payloads.OrderBy(p => p.Kind, StringComparer.Ordinal))
+        {
+            var digest = ComputeDigest(payload.Content.Span);
+            map[payload.Kind] = digest;
+        }
+
+        // Build Merkle-like root by hashing the ordered list of kind:digest lines.
+        var builder = new StringBuilder();
+        foreach (var kvp in map.OrderBy(kv => kv.Key, StringComparer.Ordinal))
+        {
+            builder.Append(kvp.Key).Append(':').Append(kvp.Value).Append('\n');
+        }
+
+        var rootBytes = Encoding.UTF8.GetBytes(builder.ToString());
+        var rootHash = sha.ComputeHash(rootBytes);
+        var merkleRoot = Convert.ToHexString(rootHash).ToLowerInvariant();
+
+        return (map, merkleRoot);
+    }
+
+    private static string? GetReplayBundleUri(ScanJobContext context)
+        => context.Lease.Metadata.TryGetValue("replay.bundle.uri", out var value) && !string.IsNullOrWhiteSpace(value)
+            ? value.Trim()
+            : null;
+
+    private static string? GetReplayBundleHash(ScanJobContext context)
+        => context.Lease.Metadata.TryGetValue("replay.bundle.sha256", out var value) && !string.IsNullOrWhiteSpace(value)
+            ? value.Trim().ToLowerInvariant()
+            : null;
+
+    private static string? GetPin(ScanJobContext context, string key)
+        => context.Lease.Metadata.TryGetValue(key, out var value) && !string.IsNullOrWhiteSpace(value)
+            ? value.Trim()
+            : null;
+
     private async Task PersistRubyPackagesAsync(ScanJobContext context, CancellationToken cancellationToken)
     {
         if (!context.Analysis.TryGet<ReadOnlyDictionary<string, LanguageAnalyzerResult>>(ScanAnalysisKeys.LanguageAnalyzerResults, out var results))

src/Scanner/StellaOps.Scanner.Worker/Program.cs

@@ -87,6 +87,8 @@ builder.Services.AddSingleton<IEntryTraceExecutionService, EntryTraceExecutionSe
 builder.Services.AddSingleton<ReachabilityUnionWriter>();
 builder.Services.AddSingleton<ReachabilityUnionPublisher>();
 builder.Services.AddSingleton<IReachabilityUnionPublisherService, ReachabilityUnionPublisherService>();
+builder.Services.AddSingleton<IScanStageExecutor, StellaOps.Scanner.Worker.Processing.Replay.ReplaySealedBundleStageExecutor>();
+builder.Services.AddSingleton<StellaOps.Scanner.Worker.Processing.Replay.ReplayBundleFetcher>();
 
 var storageSection = builder.Configuration.GetSection("ScannerStorage");
 var connectionString = storageSection.GetValue<string>("Mongo:ConnectionString");