diff --git a/src/main/agent-runtime/agent-hooks.ts b/src/main/agent-runtime/agent-hooks.ts
index 8a499b7d..eca2236c 100644
--- a/src/main/agent-runtime/agent-hooks.ts
+++ b/src/main/agent-runtime/agent-hooks.ts
@@ -78,8 +78,8 @@ export interface AgentHookBundle {
  *  - `beforeToolCall`: fail-closed RPC. A thrown error travels up into
  *    pi's loop and surfaces as a tool-error result — destructive tools
  *    must never silently bypass main's approval gate.
- *  - `afterToolCall`: fail-open RPC. Projection is observational; if
- *    main cannot be reached the tool result stands unchanged.
+ *  - `afterToolCall`: fail-closed RPC. The tool has already run, so
+ *    main must durably acknowledge the artifact projection result.
  *  - `transformContext`: worker-local compaction. The transcript stays
  *    inside the worker; main receives telemetry only.
  */
@@ -120,10 +120,7 @@ export function buildAgentHooks(deps: AgentHooksDeps): AgentHookBundle {
     };
     const response = await rpc.invoke(runId, "afterToolCall", payload);
     if (!response.ok) {
-      // After-hook failure is informational: the tool already ran,
-      // projection is a best-effort write. Drop the hook rather than
-      // corrupting the tool result.
-      return undefined;
+      throw new Error(`afterToolCall RPC failed: ${response.error}`);
     }
     const result = response.result as AfterToolCallRpcResult;
     const override: AfterToolCallResult = {};
diff --git a/src/main/agent-runtime/artifact-projection-events.ts b/src/main/agent-runtime/artifact-projection-events.ts
new file mode 100644
index 00000000..e940d1f4
--- /dev/null
+++ b/src/main/agent-runtime/artifact-projection-events.ts
@@ -0,0 +1,105 @@
+import type { AppDatabase } from "@main/database";
+import type { ProjectionOutcome } from "./artifact-types";
+
+export type ArtifactProjectionPhase = "after_tool_call" | "completion_reconcile";
+
+export interface ArtifactProjectionEventInput {
+  companyId: string;
+  runId: string;
+  agentId: string;
+  phase: ArtifactProjectionPhase;
+  workspaceId: string | null;
+  workspaceMode: "exclusive" | "shared" | "none";
+  toolName?: string | null;
+  toolCallId?: string | null;
+  outcomes: ProjectionOutcome[];
+}
+
+export interface ArtifactProjectionFailureInput {
+  companyId: string;
+  runId: string;
+  agentId: string;
+  phase: ArtifactProjectionPhase;
+  workspaceId: string | null;
+  workspaceMode: "exclusive" | "shared" | "none";
+  toolName?: string | null;
+  toolCallId?: string | null;
+  errorMessage: string;
+}
+
+interface ProjectionCounts {
+  inserted: number;
+  updated: number;
+  retired: number;
+  skipped: number;
+}
+
+function countOutcomes(outcomes: ProjectionOutcome[]): ProjectionCounts {
+  const counts: ProjectionCounts = {
+    inserted: 0,
+    updated: 0,
+    retired: 0,
+    skipped: 0,
+  };
+  for (const outcome of outcomes) {
+    counts[outcome.kind] += 1;
+  }
+  return counts;
+}
+
+function summarizeOutcomes(phase: ArtifactProjectionPhase, counts: ProjectionCounts): string {
+  return [
+    `Artifact projection ${phase} acknowledged`,
+    `${counts.inserted} inserted`,
+    `${counts.updated} updated`,
+    `${counts.retired} retired`,
+    `${counts.skipped} skipped`,
+  ].join("; ");
+}
+
+export function appendArtifactProjectionEvent(
+  db: AppDatabase,
+  input: ArtifactProjectionEventInput,
+): ProjectionCounts {
+  const counts = countOutcomes(input.outcomes);
+  db.core.runs.appendRunEvent({
+    companyId: input.companyId,
+    runId: input.runId,
+    agentId: input.agentId,
+    eventType: "artifact_projection",
+    level: "info",
+    message: summarizeOutcomes(input.phase, counts),
+    payload: {
+      phase: input.phase,
+      workspaceId: input.workspaceId,
+      workspaceMode: input.workspaceMode,
+      toolName: input.toolName ?? null,
+      toolCallId: input.toolCallId ?? null,
+      counts,
+      outcomes: input.outcomes,
+    },
+  });
+  return counts;
+}
+
+export function appendArtifactProjectionFailureEvent(
+  db: AppDatabase,
+  input: ArtifactProjectionFailureInput,
+): void {
+  db.core.runs.appendRunEvent({
+    companyId: input.companyId,
+    runId: input.runId,
+    agentId: input.agentId,
+    eventType: "artifact_projection",
+    level: "error",
+    message: `Artifact projection ${input.phase} failed: ${input.errorMessage}`,
+    payload: {
+      phase: input.phase,
+      workspaceId: input.workspaceId,
+      workspaceMode: input.workspaceMode,
+      toolName: input.toolName ?? null,
+      toolCallId: input.toolCallId ?? null,
+      errorMessage: input.errorMessage,
+    },
+  });
+}
diff --git a/src/main/agent-runtime/artifact-projector.ts b/src/main/agent-runtime/artifact-projector.ts
index fde232ec..8d4e57a3 100644
--- a/src/main/agent-runtime/artifact-projector.ts
+++ b/src/main/agent-runtime/artifact-projector.ts
@@ -81,9 +81,6 @@ export function reconcileWorkspaceArtifacts(
   db: AppDatabase,
   ctx: ArtifactProjectorRunContext,
 ): ProjectionOutcome[] {
-  if (ctx.workspaceMode !== "exclusive") {
-    return [{ kind: "skipped", reason: "workspace_not_exclusive" }];
-  }
   return projectCollectedChanges(db, ctx, collectChangedPaths(ctx));
 }
 
@@ -91,9 +88,6 @@ function projectBashArtifacts(
   db: AppDatabase,
   ctx: ArtifactProjectorRunContext,
 ): ProjectionOutcome[] {
-  if (ctx.workspaceMode !== "exclusive") {
-    return [{ kind: "skipped", reason: "workspace_not_exclusive" }];
-  }
   return projectCollectedChanges(db, ctx, collectChangedPaths(ctx));
 }
 
diff --git a/src/main/agent-runtime/artifact-work-products.ts b/src/main/agent-runtime/artifact-work-products.ts
index 804760b0..3dd8577f 100644
--- a/src/main/agent-runtime/artifact-work-products.ts
+++ b/src/main/agent-runtime/artifact-work-products.ts
@@ -51,9 +51,14 @@ export function retireDeletedArtifacts(
   deleted: string[],
 ): ProjectionOutcome[] {
   if (deleted.length === 0) return [];
+  const resolvedWorkspaceId =
+    ctx.workspaceId ??
+    (ctx.workspacePath
+      ? db.core.workspaces.findWorkspaceIdByLocalPath(ctx.companyId, ctx.workspacePath)
+      : null);
   const archived = db.core.documents.archiveWorkProductsByExternalPaths({
     companyId: ctx.companyId,
-    workspaceId: ctx.workspaceId,
+    workspaceId: resolvedWorkspaceId,
     provider: "filesystem",
     paths: deleted,
     lastTouchedByRunId: ctx.runId,
diff --git a/src/main/agent-runtime/hook-handlers.ts b/src/main/agent-runtime/hook-handlers.ts
index ddcc4eeb..f02aae75 100644
--- a/src/main/agent-runtime/hook-handlers.ts
+++ b/src/main/agent-runtime/hook-handlers.ts
@@ -23,6 +23,10 @@ import {
   projectToolExecutionToWorkProduct,
   type ArtifactProjectorRunContext,
 } from "./artifact-projector";
+import {
+  appendArtifactProjectionEvent,
+  appendArtifactProjectionFailureEvent,
+} from "./artifact-projection-events";
 import {
   isCofounderMandatoryApproval,
   isOperationalApproval,
@@ -144,12 +148,10 @@ function checkOperationalApprovalBlock(
  * through this hook; as further projections (browser actions, social
  * posts) migrate off the event-observer path they plug in here.
  *
- * Projection is treated as a primary persistence action: failures are
- * logged at ERROR so they stay visible in the desktop log tail, and the
- * `run-finished` reconciliation sweep (`RuntimeBridge`) revisits the
- * workspace to register anything the hook missed. Silent swallow was
- * the failure mode that left `work_products` empty while the workspace
- * accumulated files the UI never surfaced.
+ * Projection is treated as a primary persistence action: the filesystem
+ * mutation and its run-event acknowledgement commit together. A failure
+ * returns an RPC error to the worker, which lets pi surface the hook
+ * failure as a deterministic tool error.
  */
 export function handleAfterToolCall(
   deps: HookHandlerDeps,
@@ -168,16 +170,30 @@ export function handleAfterToolCall(
     workspaceBaseline: ctx.workspaceBaseline,
   };
   try {
-    const outcomes = projectToolExecutionToWorkProduct(
-      deps.db,
-      runCtx,
-      {
+    const outcomes = deps.db.withTransaction(() => {
+      const projectionOutcomes = projectToolExecutionToWorkProduct(
+        deps.db,
+        runCtx,
+        {
+          toolName: payload.toolName,
+          args: payload.args,
+          result: payload.resultContent,
+          isError: payload.isError,
+        },
+      );
+      appendArtifactProjectionEvent(deps.db, {
+        companyId: ctx.companyId,
+        runId: ctx.runId,
+        agentId: ctx.agentId,
+        phase: "after_tool_call",
+        workspaceId: ctx.workspaceId,
+        workspaceMode: ctx.workspaceMode,
         toolName: payload.toolName,
-        args: payload.args,
-        result: payload.resultContent,
-        isError: payload.isError,
-      },
-    );
+        toolCallId: payload.toolCallId,
+        outcomes: projectionOutcomes,
+      });
+      return projectionOutcomes;
+    });
     const registered = outcomes.filter((o) => o.kind === "inserted" || o.kind === "updated").length;
     const retired = outcomes.filter((o) => o.kind === "retired").length;
     if (registered > 0 || retired > 0) {
@@ -186,9 +202,28 @@ export function handleAfterToolCall(
       );
     }
   } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    try {
+      appendArtifactProjectionFailureEvent(deps.db, {
+        companyId: ctx.companyId,
+        runId: ctx.runId,
+        agentId: ctx.agentId,
+        phase: "after_tool_call",
+        workspaceId: ctx.workspaceId,
+        workspaceMode: ctx.workspaceMode,
+        toolName: payload.toolName,
+        toolCallId: payload.toolCallId,
+        errorMessage,
+      });
+    } catch (ackError) {
+      deps.logger.error(
+        `[hook-handlers] artifact projection failure ack failed for run ${ctx.runId} tool ${payload.toolName}: ${ackError instanceof Error ? ackError.message : String(ackError)}`,
+      );
+    }
     deps.logger.error(
-      `[hook-handlers] artifact projection threw for run ${ctx.runId} tool ${payload.toolName}: ${error instanceof Error ? error.message : String(error)}`,
+      `[hook-handlers] artifact projection threw for run ${ctx.runId} tool ${payload.toolName}: ${errorMessage}`,
     );
+    throw error;
   }
   return NO_OP_AFTER;
 }
diff --git a/src/main/agent-runtime/runtime-artifact-reconciler.ts b/src/main/agent-runtime/runtime-artifact-reconciler.ts
new file mode 100644
index 00000000..26872e53
--- /dev/null
+++ b/src/main/agent-runtime/runtime-artifact-reconciler.ts
@@ -0,0 +1,79 @@
+import type { AppDatabase } from "@main/database";
+import type { ActiveRunContext } from "./hook-handlers";
+import { reconcileWorkspaceArtifacts } from "./artifact-projector";
+import {
+  appendArtifactProjectionEvent,
+  appendArtifactProjectionFailureEvent,
+} from "./artifact-projection-events";
+
+export type RunResourceReleaseResult =
+  | { ok: true }
+  | { ok: false; errorMessage: string };
+
+export interface RuntimeArtifactReconcilerDeps {
+  db: AppDatabase;
+  logger: {
+    info: (...args: unknown[]) => void;
+    error: (...args: unknown[]) => void;
+  };
+}
+
+export function reconcileArtifactsForActiveRun(
+  deps: RuntimeArtifactReconcilerDeps,
+  ctx: ActiveRunContext,
+): RunResourceReleaseResult {
+  try {
+    const outcomes = deps.db.withTransaction(() => {
+      const projectionOutcomes = reconcileWorkspaceArtifacts(deps.db, {
+        runId: ctx.runId,
+        agentId: ctx.agentId,
+        companyId: ctx.companyId,
+        taskId: ctx.taskId,
+        workspaceId: ctx.workspaceId,
+        workspacePath: ctx.workspacePath,
+        workspaceMode: ctx.workspaceMode,
+        logger: deps.logger,
+        workspaceBaseline: ctx.workspaceBaseline,
+      });
+      appendArtifactProjectionEvent(deps.db, {
+        companyId: ctx.companyId,
+        runId: ctx.runId,
+        agentId: ctx.agentId,
+        phase: "completion_reconcile",
+        workspaceId: ctx.workspaceId,
+        workspaceMode: ctx.workspaceMode,
+        outcomes: projectionOutcomes,
+      });
+      return projectionOutcomes;
+    });
+    const inserted = outcomes.filter((o) => o.kind === "inserted").length;
+    const retired = outcomes.filter((o) => o.kind === "retired").length;
+    if (inserted > 0 || retired > 0) {
+      deps.logger.info(
+        `[runtime-bridge] reconciliation for run ${ctx.runId}: ${inserted} registered, ${retired} retired`,
+      );
+    }
+    return { ok: true };
+  } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    try {
+      appendArtifactProjectionFailureEvent(deps.db, {
+        companyId: ctx.companyId,
+        runId: ctx.runId,
+        agentId: ctx.agentId,
+        phase: "completion_reconcile",
+        workspaceId: ctx.workspaceId,
+        workspaceMode: ctx.workspaceMode,
+        errorMessage,
+      });
+    } catch (ackError) {
+      deps.logger.error(
+        `[runtime-bridge] artifact reconciliation failure ack failed for run ${ctx.runId}: ${ackError instanceof Error ? ackError.message : String(ackError)}`,
+      );
+    }
+    deps.logger.error(
+      `[runtime-bridge] artifact reconciliation failed for run ${ctx.runId}: ${errorMessage}`,
+    );
+    return { ok: false, errorMessage };
+  }
+}
diff --git a/src/main/agent-runtime/runtime-bridge.ts b/src/main/agent-runtime/runtime-bridge.ts
index 51425ab8..87a4487c 100644
--- a/src/main/agent-runtime/runtime-bridge.ts
+++ b/src/main/agent-runtime/runtime-bridge.ts
@@ -8,7 +8,11 @@ import { getConnectorDefinition } from "@main/connectors";
 import { projectInboxMessageToPi } from "./inbox-projection";
 import { projectAgentEventToLogChunk } from "./agent-event-projection";
 import { hasAttributableAssistantUsage } from "../run-usage-status";
-import { captureBaselineIfRequired, reconcileWorkspaceArtifacts } from "./artifact-projector";
+import { captureBaselineIfRequired } from "./artifact-projector";
+import {
+  reconcileArtifactsForActiveRun,
+  type RunResourceReleaseResult,
+} from "./runtime-artifact-reconciler";
 import {
   handleBeforeToolCall,
   handleAfterToolCall,
@@ -134,40 +138,21 @@ export class RuntimeBridge {
    * when individual projections skipped (bash against a non-git repo,
    * path-ignore false positives, transient `git status` failures).
    */
-  releaseRunResources(runId: string): void {
+  releaseRunResources(runId: string): RunResourceReleaseResult {
     const ctx = this.activeRuns.get(runId);
-    if (ctx) this.reconcileArtifactsForRun(ctx);
-    this.activeRuns.delete(runId);
-    this.inboundCorrelations.deleteRun(runId);
-    if (ctx) this.sessionStores.delete(ctx.taskSessionId);
+    let result: RunResourceReleaseResult = { ok: true };
+    try {
+      if (ctx) result = this.reconcileArtifactsForRun(ctx);
+      return result;
+    } finally {
+      this.activeRuns.delete(runId);
+      this.inboundCorrelations.deleteRun(runId);
+      if (ctx) this.sessionStores.delete(ctx.taskSessionId);
+    }
   }
 
-  private reconcileArtifactsForRun(ctx: ActiveRunContext): void {
-    if (!ctx.workspacePath) return;
-    try {
-      const outcomes = reconcileWorkspaceArtifacts(this.deps.db, {
-        runId: ctx.runId,
-        agentId: ctx.agentId,
-        companyId: ctx.companyId,
-        taskId: ctx.taskId,
-        workspaceId: ctx.workspaceId,
-        workspacePath: ctx.workspacePath,
-        workspaceMode: ctx.workspaceMode,
-        logger: this.deps.logger,
-        workspaceBaseline: ctx.workspaceBaseline,
-      });
-      const inserted = outcomes.filter((o) => o.kind === "inserted").length;
-      const retired = outcomes.filter((o) => o.kind === "retired").length;
-      if (inserted > 0 || retired > 0) {
-        this.deps.logger.info(
-          `[runtime-bridge] reconciliation for run ${ctx.runId}: ${inserted} registered, ${retired} retired`,
-        );
-      }
-    } catch (error) {
-      this.deps.logger.error(
-        `[runtime-bridge] artifact reconciliation failed for run ${ctx.runId}: ${error instanceof Error ? error.message : String(error)}`,
-      );
-    }
+  private reconcileArtifactsForRun(ctx: ActiveRunContext): RunResourceReleaseResult {
+    return reconcileArtifactsForActiveRun(this.deps, ctx);
   }
 
   /**
@@ -397,11 +382,7 @@ export class RuntimeBridge {
       workspacePath: string | null;
       workspaceMode: "exclusive" | "shared" | "none";
     };
-    // Baseline scans are safe only while this run owns the workspace lock.
-    const baseline =
-      payload.workspaceMode === "exclusive"
-        ? captureBaselineIfRequired(payload.workspacePath, this.deps.logger)
-        : null;
+    const baseline = captureBaselineIfRequired(payload.workspacePath, this.deps.logger);
     this.registerActiveRun({
       runId,
       agentId: payload.agentId,
diff --git a/src/main/database/runs.ts b/src/main/database/runs.ts
index 086ce293..53d53e4b 100644
--- a/src/main/database/runs.ts
+++ b/src/main/database/runs.ts
@@ -258,6 +258,17 @@ export function buildRunMethods(
       return { budgetHardStopped };
     },
 
+    markRunCompletionFailure(runId: string, errorMessage: string): void {
+      const ts = nowIso();
+      transaction(() => {
+        getDb()
+          .prepare(
+            "update runs set status = 'failed', summary = ?, error_message = ?, usage_status = 'error_stop', finished_at = coalesce(finished_at, ?), updated_at = ? where id = ?",
+          )
+          .run("Run completion blocked by artifact projection failure.", errorMessage, ts, ts, runId);
+      });
+    },
+
     cancelRunForDeletion(runId: string, taskId: string | null, workspaceId: string | null, summary: string) {
       const ts = nowIso();
       getDb()
diff --git a/src/main/worker/entry/message-handler.ts b/src/main/worker/entry/message-handler.ts
index f5612cc6..48ad061c 100644
--- a/src/main/worker/entry/message-handler.ts
+++ b/src/main/worker/entry/message-handler.ts
@@ -7,6 +7,7 @@ import { releaseCompletedRunWorkspaceLock } from "../handlers/run-finished-helpe
 import { handleContextCompaction } from "../handlers/context-compaction-handler";
 import type { HandlerContext, HandlerDeps } from "../handlers/handler-context";
 import type { RunFinishedContext } from "../handlers/run-finished-helpers";
+import type { RunResourceReleaseResult } from "../../agent-runtime/runtime-artifact-reconciler";
 
 export async function handleWorkerMessage(
   message: unknown,
@@ -50,10 +51,21 @@ export async function handleWorkerMessage(
       return;
     case "run-finished": {
       let completion: RunFinishedContext | null = null;
+      let runtimeResourcesReleased = false;
+      let runtimeReleaseResult: RunResourceReleaseResult = { ok: true };
+      const releaseRuntimeResources = (): RunResourceReleaseResult => {
+        if (runtimeResourcesReleased) return runtimeReleaseResult;
+        runtimeResourcesReleased = true;
+        runtimeReleaseResult =
+          deps.getRuntimeBridge?.()?.releaseRunResources(event.runId) ?? { ok: true };
+        return runtimeReleaseResult;
+      };
       try {
-        completion = handleRunFinished(event, deps, context);
+        completion = handleRunFinished(event, deps, context, {
+          beforePostCompletionAutomation: releaseRuntimeResources,
+        });
       } finally {
-        deps.getRuntimeBridge?.()?.releaseRunResources(event.runId);
+        releaseRuntimeResources();
       }
       releaseCompletedRunWorkspaceLock(completion, deps);
       if (!worker) {
diff --git a/src/main/worker/handlers/run-finished-handler.ts b/src/main/worker/handlers/run-finished-handler.ts
index 97f44a38..9ccd2707 100644
--- a/src/main/worker/handlers/run-finished-handler.ts
+++ b/src/main/worker/handlers/run-finished-handler.ts
@@ -8,17 +8,39 @@ import {
 import type { HandlerContext, HandlerDeps, WorkerMessageEvent } from "./handler-context";
 import type { RunFinishedContext } from "./run-finished-helpers";
 
+export interface RunFinishedHooks {
+  beforePostCompletionAutomation?: (context: RunFinishedContext) =>
+    | void
+    | { ok: true }
+    | { ok: false; errorMessage: string };
+}
+
 export function handleRunFinished(
   event: Extract<WorkerMessageEvent, { type: "run-finished" }>,
   deps: HandlerDeps,
   context: HandlerContext,
+  hooks: RunFinishedHooks = {},
 ): RunFinishedContext | null {
   const rfCtx = finalizeRun(event, deps, context);
   if (!rfCtx) return null;
 
   accumulateAndRotateSession(event, deps, rfCtx);
-  emitAndNotifyCompletion(event, deps, rfCtx);
-  const { hadDeferredWakes } = runPostCompletionAutomation(event, deps, context, rfCtx);
-  triggerSelfWake(event, deps, context, rfCtx, hadDeferredWakes);
+  const boundaryResult = hooks.beforePostCompletionAutomation?.(rfCtx);
+  const effectiveEvent =
+    boundaryResult && !boundaryResult.ok
+      ? {
+          ...event,
+          status: "failed" as const,
+          summary: null,
+          errorMessage: boundaryResult.errorMessage,
+          usageStatus: "error_stop" as const,
+        }
+      : event;
+  if (boundaryResult && !boundaryResult.ok) {
+    deps.db.core.runs.markRunCompletionFailure(event.runId, boundaryResult.errorMessage);
+  }
+  emitAndNotifyCompletion(effectiveEvent, deps, rfCtx);
+  const { hadDeferredWakes } = runPostCompletionAutomation(effectiveEvent, deps, context, rfCtx);
+  triggerSelfWake(effectiveEvent, deps, context, rfCtx, hadDeferredWakes);
   return rfCtx;
 }
diff --git a/tests/integration/artifact-projection-ack.spec.ts b/tests/integration/artifact-projection-ack.spec.ts
new file mode 100644
index 00000000..b48c369e
--- /dev/null
+++ b/tests/integration/artifact-projection-ack.spec.ts
@@ -0,0 +1,177 @@
+import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { RuntimeBridge } from "../../src/main/agent-runtime";
+import { AppDatabase } from "../../src/main/database";
+import type { CredentialResolver } from "../../src/main/credentials";
+
+const tempDirs: string[] = [];
+
+async function createTempDir(prefix: string): Promise<string> {
+  const dir = await mkdtemp(join(tmpdir(), prefix));
+  tempDirs.push(dir);
+  return dir;
+}
+
+afterEach(async () => {
+  await Promise.all(tempDirs.splice(0).map((dir) => rm(dir, { recursive: true, force: true })));
+});
+
+async function createHarness() {
+  const profileDir = await createTempDir("agentcompany-artifact-ack-");
+  const workspacePath = await createTempDir("agentcompany-artifact-workspace-");
+  const db = new AppDatabase(profileDir);
+  db.init();
+  const companyId = db.core.company.saveCompany({
+    name: "Artifact Ack Co",
+    description: "Durable artifact projection test",
+    status: "active",
+  });
+  const workspaceId = db.core.workspaces.saveWorkspace({
+    companyId,
+    name: "Primary",
+    localPath: workspacePath,
+    repoUrl: "",
+    repoRef: "",
+    isPrimary: true,
+  });
+  const agentId = db.core.agents.saveAgent({
+    companyId,
+    name: "Artifact Agent",
+    role: "Engineer",
+    title: "Engineer",
+    status: "active",
+    reportsTo: null,
+    connectorId: "openai-codex",
+    workspaceId,
+    model: null,
+    capabilities: "Writes files",
+    budgetMonthlyUsd: 100,
+  });
+  const taskId = db.core.tasks.saveTask({
+    companyId,
+    title: "Produce artifact",
+    description: "",
+    assigneeAgentId: agentId,
+    workspaceId,
+    priority: "medium",
+    status: "in_progress",
+  });
+  const run = db.core.runs.createRun({
+    companyId,
+    taskId,
+    agentId,
+    workspaceId: null,
+    connectorId: "openai-codex",
+  });
+  const bridge = new RuntimeBridge({
+    db,
+    emitEvent: vi.fn(),
+    logger: {
+      info: vi.fn(),
+      warn: vi.fn(),
+      error: vi.fn(),
+    },
+    credentialResolver: {
+      resolve: vi.fn(async () => ({ apiKey: "test-api-key", extraEnv: {} })),
+    } as unknown as CredentialResolver,
+  });
+
+  const prepare = await bridge.handleRpc({
+    rpcId: "prepare",
+    method: "prepareRun",
+    runId: run.id,
+    payload: {
+      connectorId: "openai-codex",
+      taskSessionId: "task-session-artifact-ack",
+      agentId,
+      companyId,
+      taskId,
+      modelId: "gpt-5.3-codex",
+      workspaceId: null,
+      workspacePath,
+      workspaceMode: "none",
+    },
+  });
+  expect(prepare.ok).toBe(true);
+
+  return {
+    db,
+    bridge,
+    companyId,
+    workspacePath,
+    agentId,
+    taskId,
+    runId: run.id,
+  };
+}
+
+describe("artifact projection durable ack", () => {
+  it("persists afterToolCall projection outcomes to the run event tail", async () => {
+    const harness = await createHarness();
+    try {
+      await mkdir(join(harness.workspacePath, "reports"), { recursive: true });
+      await writeFile(join(harness.workspacePath, "reports", "hook.md"), "hook artifact", "utf8");
+
+      const response = await harness.bridge.handleRpc({
+        rpcId: "after-tool",
+        method: "afterToolCall",
+        runId: harness.runId,
+        payload: {
+          toolName: "write",
+          toolCallId: "tool-call-hook",
+          args: { path: "reports/hook.md" },
+          resultContent: [],
+          resultDetails: null,
+          isError: false,
+        },
+      });
+
+      expect(response.ok).toBe(true);
+      const event = harness.db.core.runs.listRunEvents(harness.runId, harness.companyId)[0];
+      expect(event).toMatchObject({
+        eventType: "artifact_projection",
+        level: "info",
+      });
+      expect(event?.payload).toMatchObject({
+        phase: "after_tool_call",
+        toolName: "write",
+        toolCallId: "tool-call-hook",
+        workspaceMode: "none",
+        counts: { inserted: 1, updated: 0, retired: 0, skipped: 0 },
+      });
+    } finally {
+      harness.db.close();
+    }
+  });
+
+  it("runs completion reconciliation before resource release for non-exclusive observation workspaces", async () => {
+    const harness = await createHarness();
+    try {
+      await mkdir(join(harness.workspacePath, "reports"), { recursive: true });
+      await writeFile(join(harness.workspacePath, "reports", "completion.md"), "completion artifact", "utf8");
+
+      harness.bridge.releaseRunResources(harness.runId);
+
+      expect(
+        harness.db.projection.snapshot.listSnapshot().workProducts.some(
+          (entry) => entry.externalId === "reports/completion.md",
+        ),
+      ).toBe(true);
+      const events = harness.db.core.runs.listRunEvents(harness.runId, harness.companyId);
+      expect(events).toHaveLength(1);
+      expect(events[0]).toMatchObject({
+        eventType: "artifact_projection",
+        level: "info",
+      });
+      expect(events[0]?.payload).toMatchObject({
+        phase: "completion_reconcile",
+        workspaceMode: "none",
+        counts: { inserted: 1, updated: 0, retired: 0, skipped: 0 },
+      });
+    } finally {
+      harness.db.close();
+    }
+  });
+});
diff --git a/tests/integration/work-products-lifecycle.spec.ts b/tests/integration/work-products-lifecycle.spec.ts
index 758fa6a9..d2c44b92 100644
--- a/tests/integration/work-products-lifecycle.spec.ts
+++ b/tests/integration/work-products-lifecycle.spec.ts
@@ -5,6 +5,7 @@ import { tmpdir } from "node:os";
 import { afterEach, describe, expect, it } from "vitest";
 import { AppDatabase } from "../../src/main/database";
 import {
+  projectToolExecutionToWorkProduct,
   reconcileWorkspaceArtifacts,
   type ArtifactProjectorRunContext,
 } from "../../src/main/agent-runtime/artifact-projector";
@@ -236,6 +237,85 @@ describe("work_products archived visibility", () => {
 });
 
 describe("work_products bulk retirement", () => {
+  it("registers bash artifacts from non-exclusive observation workspaces", async () => {
+    const harness = await createHarness();
+    try {
+      const ctx: ArtifactProjectorRunContext = {
+        runId: harness.runId,
+        agentId: harness.agentId,
+        companyId: harness.companyId,
+        taskId: harness.taskId,
+        workspaceId: null,
+        workspacePath: harness.workspacePath,
+        workspaceMode: "none",
+        workspaceBaseline: {
+          mtimeByRelPath: new Map<string, number>(),
+          capturedAt: Date.now(),
+          truncated: false,
+        },
+      };
+      await mkdir(join(harness.workspacePath, "reports"), { recursive: true });
+      await writeFile(join(harness.workspacePath, "reports", "non-exclusive.md"), "observed", "utf8");
+
+      const outcomes = projectToolExecutionToWorkProduct(harness.db, ctx, {
+        toolName: "bash",
+        args: { command: "printf observed > reports/non-exclusive.md" },
+        result: null,
+        isError: false,
+      });
+
+      expect(outcomes).toEqual([
+        expect.objectContaining({
+          kind: "inserted",
+          relativePath: "reports/non-exclusive.md",
+        }),
+      ]);
+      expect(
+        harness.db.projection.snapshot.listSnapshot().workProducts.some(
+          (entry) => entry.externalId === "reports/non-exclusive.md",
+        ),
+      ).toBe(true);
+    } finally {
+      harness.db.close();
+    }
+  });
+
+  it("retires deleted artifacts from non-exclusive observation workspaces", async () => {
+    const harness = await createHarness();
+    try {
+      const relPath = "reports/non-exclusive-retired.md";
+      const workProductId = registerArtifact(harness, relPath);
+      await unlink(join(harness.workspacePath, relPath));
+
+      const outcomes = reconcileWorkspaceArtifacts(harness.db, {
+        runId: harness.runId,
+        agentId: harness.agentId,
+        companyId: harness.companyId,
+        taskId: harness.taskId,
+        workspaceId: null,
+        workspacePath: harness.workspacePath,
+        workspaceMode: "none",
+        workspaceBaseline: {
+          mtimeByRelPath: new Map<string, number>([[relPath, Date.now()]]),
+          capturedAt: Date.now(),
+          truncated: false,
+        },
+      });
+
+      expect(outcomes).toEqual([
+        expect.objectContaining({
+          kind: "retired",
+          relativePath: relPath,
+        }),
+      ]);
+      expect(
+        harness.db.core.documents.resolveWorkProductTarget(workProductId, harness.companyId),
+      ).toMatchObject({ kind: "error", reason: "archived" });
+    } finally {
+      harness.db.close();
+    }
+  });
+
   it("archives every deletion past the previous 50-path budget", async () => {
     const harness = await createHarness();
     try {
diff --git a/tests/unit/agent-hooks.test.ts b/tests/unit/agent-hooks.test.ts
new file mode 100644
index 00000000..1eb2fb69
--- /dev/null
+++ b/tests/unit/agent-hooks.test.ts
@@ -0,0 +1,28 @@
+import { describe, expect, it, vi } from "vitest";
+import { buildAgentHooks } from "../../src/main/agent-runtime/agent-hooks";
+import type { WorkerRpcClient } from "../../src/main/worker/entry/rpc";
+
+function createRpc(response: { ok: true; result: unknown } | { ok: false; error: string }) {
+  return {
+    invoke: vi.fn(async () => response),
+  } as unknown as WorkerRpcClient & { invoke: ReturnType<typeof vi.fn> };
+}
+
+describe("agent hook RPC policy", () => {
+  it("fails afterToolCall when main cannot acknowledge artifact projection", async () => {
+    const rpc = createRpc({ ok: false, error: "RuntimeBridge unavailable" });
+    const hooks = buildAgentHooks({
+      runId: "11111111-1111-4111-8111-111111111111",
+      rpc,
+    });
+
+    await expect(
+      hooks.afterToolCall({
+        toolCall: { name: "write", id: "tool-call-1" },
+        args: { path: "report.md" },
+        result: { content: [], details: null },
+        isError: false,
+      } as unknown as Parameters<typeof hooks.afterToolCall>[0]),
+    ).rejects.toThrow("afterToolCall RPC failed: RuntimeBridge unavailable");
+  });
+});
diff --git a/tests/unit/artifact-projector-errors.test.ts b/tests/unit/artifact-projector-errors.test.ts
index 97102920..80a34482 100644
--- a/tests/unit/artifact-projector-errors.test.ts
+++ b/tests/unit/artifact-projector-errors.test.ts
@@ -86,7 +86,7 @@ describe("artifact projector error taxonomy", () => {
     expect(logger.error).not.toHaveBeenCalled();
   });
 
-  it("skips broad bash projection when the run has no exclusive workspace lock", async () => {
+  it("skips broad bash projection when the run has no change source", async () => {
     const workspacePath = await createTempDir("agentcompany-shared-artifacts-");
     const ctx: ArtifactProjectorRunContext = {
       runId: "run-shared",
@@ -105,9 +105,9 @@ describe("artifact projector error taxonomy", () => {
       args: { command: "touch report.md" },
       result: null,
       isError: false,
-    })).toEqual([{ kind: "skipped", reason: "workspace_not_exclusive" }]);
+    })).toEqual([{ kind: "skipped", reason: "no_baseline" }]);
     expect(reconcileWorkspaceArtifacts({} as AppDatabase, ctx)).toEqual([
-      { kind: "skipped", reason: "workspace_not_exclusive" },
+      { kind: "skipped", reason: "no_baseline" },
     ]);
   });
 });
diff --git a/tests/unit/worker-completion-boundary.test.ts b/tests/unit/worker-completion-boundary.test.ts
index 043e8f38..9b57ae9b 100644
--- a/tests/unit/worker-completion-boundary.test.ts
+++ b/tests/unit/worker-completion-boundary.test.ts
@@ -3,6 +3,7 @@ import { describe, it, expect, vi, afterEach } from "vitest";
 import { handleWorkerMessage } from "@main/worker/entry/message-handler";
 import { workerMessageSchema } from "@main/worker/entry/types";
 import type { RunJob } from "@main/worker/runtime/helpers";
+import type { RunResourceReleaseResult } from "@main/agent-runtime/runtime-artifact-reconciler";
 
 const RUN_ID = "00000000-0000-4000-8000-000000000001";
 const NEXT_RUN_ID = "00000000-0000-4000-8000-000000000002";
@@ -31,7 +32,11 @@ function createHandlerDeps(calls: string[]) {
   });
   const rotateSession = vi.fn(() => calls.push("rotateSession"));
   const processRunCompletion = vi.fn(() => calls.push("processRunCompletion"));
-  const releaseRunResources = vi.fn(() => calls.push("releaseRunResources"));
+  const releaseRunResources = vi.fn((): RunResourceReleaseResult => {
+    calls.push("releaseRunResources");
+    return { ok: true as const };
+  });
+  const markRunCompletionFailure = vi.fn(() => calls.push("markRunCompletionFailure"));
 
   const db = {
     core: {
@@ -44,6 +49,7 @@ function createHandlerDeps(calls: string[]) {
           workspaceId: "workspace-1",
         })),
         finishRun,
+        markRunCompletionFailure,
       },
       workspaces: { releaseWorkspaceLock },
       activity: { addActivity: vi.fn(() => calls.push("addActivity")) },
@@ -104,6 +110,7 @@ function createHandlerDeps(calls: string[]) {
     rotateSession,
     processRunCompletion,
     releaseRunResources,
+    markRunCompletionFailure,
   };
 }
 
@@ -137,7 +144,7 @@ describe("worker completion boundary", () => {
     Reflect.deleteProperty(process, "parentPort");
   });
 
-  it("releases the workspace lock after session, automation, and runtime resource release", async () => {
+  it("runs artifact reconciliation before automation and releases the workspace lock last", async () => {
     const calls: string[] = [];
     const {
       deps,
@@ -167,6 +174,9 @@ describe("worker completion boundary", () => {
     expect(releaseWorkspaceLock.mock.invocationCallOrder[0]).toBeGreaterThan(
       rotateSession.mock.invocationCallOrder[0]!,
     );
+    expect(processRunCompletion.mock.invocationCallOrder[0]).toBeGreaterThan(
+      releaseRunResources.mock.invocationCallOrder[0]!,
+    );
     expect(releaseWorkspaceLock.mock.invocationCallOrder[0]).toBeGreaterThan(
       processRunCompletion.mock.invocationCallOrder[0]!,
     );
@@ -175,6 +185,48 @@ describe("worker completion boundary", () => {
     );
   });
 
+  it("marks run completion failed and blocks success automation when artifact reconciliation fails", async () => {
+    const calls: string[] = [];
+    const {
+      deps,
+      releaseWorkspaceLock,
+      processRunCompletion,
+      releaseRunResources,
+      markRunCompletionFailure,
+    } = createHandlerDeps(calls);
+    releaseRunResources.mockImplementationOnce(() => {
+      calls.push("releaseRunResources");
+      return { ok: false as const, errorMessage: "completion_reconcile failed" };
+    });
+    const worker = { postMessage: vi.fn(() => calls.push("completionAck")) };
+
+    await handleWorkerMessage(
+      runFinishedMessage(RUN_ID),
+      worker as never,
+      deps as never,
+      workerMessageSchema,
+      false,
+      2,
+      30_000,
+      new Map(),
+      3,
+      new Set(),
+      new Map(),
+    );
+
+    expect(markRunCompletionFailure).toHaveBeenCalledWith(RUN_ID, "completion_reconcile failed");
+    expect(processRunCompletion).toHaveBeenCalledWith(
+      expect.objectContaining({ id: RUN_ID }),
+      expect.objectContaining({
+        status: "failed",
+        errorMessage: "completion_reconcile failed",
+        usageStatus: "error_stop",
+      }),
+    );
+    expect(releaseWorkspaceLock).toHaveBeenCalledWith("workspace-1", RUN_ID);
+    expect(worker.postMessage).toHaveBeenCalledWith({ type: "run-completion-ack", runId: RUN_ID });
+  });
+
   it("keeps same-workspace runs queued until parent acknowledges completion", async () => {
     const parentPort = new EventEmitter() as EventEmitter & {
       postMessage: ReturnType<typeof vi.fn>;