diff --git a/apps/server/src/orchestration/Layers/ProjectionPipeline.test.ts b/apps/server/src/orchestration/Layers/ProjectionPipeline.test.ts
index 543d469458ed..ea3f11aa83e0 100644
--- a/apps/server/src/orchestration/Layers/ProjectionPipeline.test.ts
+++ b/apps/server/src/orchestration/Layers/ProjectionPipeline.test.ts
@@ -10,11 +10,12 @@ import {
   ProviderInstanceId,
 } from "@t3tools/contracts";
 import * as NodeServices from "@effect/platform-node/NodeServices";
-import { assert, it } from "@effect/vitest";
+import { assert, it, vi } from "@effect/vitest";
 import * as Effect from "effect/Effect";
 import * as FileSystem from "effect/FileSystem";
 import * as Layer from "effect/Layer";
 import * as Path from "effect/Path";
+import * as Stream from "effect/Stream";
 import * as SqlClient from "effect/unstable/sql/SqlClient";
 
 import { OrchestrationCommandReceiptRepositoryLive } from "../../persistence/Layers/OrchestrationCommandReceipts.ts";
@@ -1609,6 +1610,102 @@ it.layer(Layer.fresh(makeProjectionPipelinePrefixedTestLayer("t3-bootstrap-attac
   },
 );
 
+it.layer(Layer.fresh(makeProjectionPipelinePrefixedTestLayer("t3-bootstrap-incomplete-")))(
+  "OrchestrationProjectionPipeline attachment bootstrap reconciliation",
+  (it) => {
+    it.effect("preserves attachment files when replay stops before the event log head", () =>
+      Effect.gen(function* () {
+        const fileSystem = yield* FileSystem.FileSystem;
+        const path = yield* Path.Path;
+        const projectionPipeline = yield* OrchestrationProjectionPipeline;
+        const eventStore = yield* OrchestrationEventStore;
+        const sql = yield* SqlClient.SqlClient;
+        const { attachmentsDir } = yield* ServerConfig;
+        const now = "2026-01-03T00:00:00.000Z";
+        const threadId = ThreadId.make("bootstrap-incomplete-thread");
+        const attachmentId = "bootstrap-incomplete-thread-00000000-0000-4000-8000-000000000001";
+        const attachmentPath = path.join(attachmentsDir, `${attachmentId}.png`);
+
+        yield* eventStore.append({
+          type: "thread.created",
+          eventId: EventId.make("evt-bootstrap-incomplete-1"),
+          aggregateKind: "thread",
+          aggregateId: threadId,
+          occurredAt: now,
+          commandId: CommandId.make("cmd-bootstrap-incomplete-1"),
+          causationEventId: null,
+          correlationId: CorrelationId.make("cmd-bootstrap-incomplete-1"),
+          metadata: {},
+          payload: {
+            threadId,
+            projectId: ProjectId.make("project-bootstrap-incomplete"),
+            title: "Incomplete replay",
+            modelSelection: {
+              instanceId: ProviderInstanceId.make("codex"),
+              model: "gpt-5-codex",
+            },
+            runtimeMode: "full-access",
+            branch: null,
+            worktreePath: null,
+            createdAt: now,
+            updatedAt: now,
+          },
+        });
+        yield* eventStore.append({
+          type: "thread.message-sent",
+          eventId: EventId.make("evt-bootstrap-incomplete-2"),
+          aggregateKind: "thread",
+          aggregateId: threadId,
+          occurredAt: now,
+          commandId: CommandId.make("cmd-bootstrap-incomplete-2"),
+          causationEventId: null,
+          correlationId: CorrelationId.make("cmd-bootstrap-incomplete-2"),
+          metadata: {},
+          payload: {
+            threadId,
+            messageId: MessageId.make("message-bootstrap-incomplete"),
+            role: "user",
+            text: "not replayed",
+            attachments: [
+              {
+                type: "image",
+                id: attachmentId,
+                name: "preserve.png",
+                mimeType: "image/png",
+                sizeBytes: 4,
+              },
+            ],
+            turnId: null,
+            streaming: false,
+            createdAt: now,
+            updatedAt: now,
+          },
+        });
+        yield* fileSystem.makeDirectory(attachmentsDir, { recursive: true });
+        yield* fileSystem.writeFileString(attachmentPath, "keep");
+
+        const readFromSequence = eventStore.readFromSequence.bind(eventStore);
+        const replaySpy = vi
+          .spyOn(eventStore, "readFromSequence")
+          .mockImplementation((sequenceExclusive, limit) =>
+            readFromSequence(sequenceExclusive, limit).pipe(Stream.take(1)),
+          );
+        yield* projectionPipeline.bootstrap.pipe(
+          Effect.ensuring(Effect.sync(() => replaySpy.mockRestore())),
+        );
+
+        const projectedMessages = yield* sql<{ readonly count: number }>`
+          SELECT COUNT(*) AS "count"
+          FROM projection_thread_messages
+          WHERE message_id = 'message-bootstrap-incomplete'
+        `;
+        assert.equal(projectedMessages[0]?.count ?? 0, 0);
+        assert.isTrue(yield* exists(attachmentPath));
+      }),
+    );
+  },
+);
+
 it.layer(BaseTestLayer)("OrchestrationProjectionPipeline", (it) => {
   it.effect("resumes from projector last_applied_sequence without replaying older events", () =>
     Effect.gen(function* () {
diff --git a/apps/server/src/orchestration/Layers/ProjectionPipeline.ts b/apps/server/src/orchestration/Layers/ProjectionPipeline.ts
index 54057048d9a1..13a380d1734d 100644
--- a/apps/server/src/orchestration/Layers/ProjectionPipeline.ts
+++ b/apps/server/src/orchestration/Layers/ProjectionPipeline.ts
@@ -1725,6 +1725,40 @@ const makeOrchestrationProjectionPipeline = Effect.fn("makeOrchestrationProjecti
     ];
 
     const reconcileAttachmentFiles = Effect.fn("reconcileAttachmentFiles")(function* () {
+      const eventHeadRows = yield* sql<{ readonly eventHead: number }>`
+        SELECT COALESCE(MAX(sequence), 0) AS "eventHead"
+        FROM orchestration_events
+      `;
+      const eventHead = eventHeadRows[0]?.eventHead ?? 0;
+      const projectorStateRows = yield* sql<{
+        readonly projector: string;
+        readonly lastAppliedSequence: number;
+      }>`
+        SELECT
+          projector,
+          last_applied_sequence AS "lastAppliedSequence"
+        FROM projection_state
+      `;
+      const lastAppliedSequenceByProjector = new Map(
+        projectorStateRows.map((row) => [row.projector, row.lastAppliedSequence]),
+      );
+      const incompleteProjectors = projectors.filter(
+        (projector) => lastAppliedSequenceByProjector.get(projector.name) !== eventHead,
+      );
+      if (incompleteProjectors.length > 0) {
+        yield* Effect.logWarning(
+          "skipping attachment reconciliation until every projector reaches the event log head",
+          {
+            eventHead,
+            incompleteProjectors: incompleteProjectors.map((projector) => ({
+              projector: projector.name,
+              lastAppliedSequence: lastAppliedSequenceByProjector.get(projector.name) ?? null,
+            })),
+          },
+        );
+        return;
+      }
+
       const entries = yield* fileSystem
         .readDirectory(serverConfig.attachmentsDir, { recursive: false })
         .pipe(Effect.orElseSucceed(() => [] as Array<string>));
@@ -1869,14 +1903,14 @@ const makeOrchestrationProjectionPipeline = Effect.fn("makeOrchestrationProjecti
       yield* Stream.runForEach(
         eventStore.readFromSequence(firstSequence, Number.MAX_SAFE_INTEGER),
         (event) =>
-        Effect.forEach(
-          projectors,
-          (projector) =>
-            event.sequence > (lastAppliedSequenceByProjector.get(projector.name) ?? 0)
-              ? runProjectorForEvent(projector, event, "bootstrap")
-              : Effect.void,
-          { concurrency: 1 },
-        ),
+          Effect.forEach(
+            projectors,
+            (projector) =>
+              event.sequence > (lastAppliedSequenceByProjector.get(projector.name) ?? 0)
+                ? runProjectorForEvent(projector, event, "bootstrap")
+                : Effect.void,
+            { concurrency: 1 },
+          ),
       );
     });