diff --git a/.changeset/descendant-cancel-delivery.md b/.changeset/descendant-cancel-delivery.md
new file mode 100644
index 000000000..b9b75d4df
--- /dev/null
+++ b/.changeset/descendant-cancel-delivery.md
@@ -0,0 +1,5 @@
+---
+"eve": patch
+---
+
+Cancelling a parent turn now delivers descendant cancellations more reliably: the cancel request retries with exponential backoff (~8s budget instead of 3s), `no_active_turn` results carry the error class that marked the target inactive, and every previously silent drop path (missing pending batch, missing child session ids, exhausted retries) now logs a warning so an uncancelled child no longer runs to completion without a trace.
diff --git a/.changeset/turn-cancel-race.md b/.changeset/turn-cancel-race.md
new file mode 100644
index 000000000..b311f9e2e
--- /dev/null
+++ b/.changeset/turn-cancel-race.md
@@ -0,0 +1,5 @@
+---
+"eve": patch
+---
+
+A turn cancellation observed while a durable turn step is returning now settles the turn as cancelled instead of losing the race to an ordinary completion. Previously the step could miss the abort signal and finish `done`, leaving the session in a completed state after the user had already cancelled. The cancel signal also now aborts in the same microtask that consumes the cancel payload, so a cancel replayed alongside a completed step can no longer lose the settle check by one task-queue hop.
diff --git a/.changeset/workflow-beta-38.md b/.changeset/workflow-beta-38.md
new file mode 100644
index 000000000..0d9365033
--- /dev/null
+++ b/.changeset/workflow-beta-38.md
@@ -0,0 +1,5 @@
+---
+"eve": patch
+---
+
+Upgrade the vendored Workflow DevKit to `@workflow/core@5.0.0-beta.38`. This picks up the upstream fix for runs going dormant after an accepted hook resume (vercel/workflow#3183): a session cancelled while parked on subagents could previously hold the accepted cancel indefinitely — its turn only settling as cancelled when unrelated traffic happened to wake the run. beta.38 also restored runtime world selection in core's `createWorld()`, which statically imports both first-party worlds; eve stubs those imports at vendor time so hosted Vercel bundles keep excluding local-world infrastructure.
diff --git a/packages/eve/package.json b/packages/eve/package.json
index 366d31f21..b385c9344 100644
--- a/packages/eve/package.json
+++ b/packages/eve/package.json
@@ -328,13 +328,13 @@
     "@vercel/otel": "catalog:",
     "@vercel/sandbox": "catalog:",
     "@vercel/sdk": "1.28.8",
-    "@workflow/core": "5.0.0-beta.37",
-    "@workflow/errors": "5.0.0-beta.13",
+    "@workflow/core": "5.0.0-beta.38",
+    "@workflow/errors": "5.0.0-beta.14",
     "@workflow/serde": "5.0.0-beta.2",
-    "@workflow/utils": "5.0.0-beta.7",
+    "@workflow/utils": "5.0.0-beta.8",
     "@workflow/world": "5.0.0-beta.23",
-    "@workflow/world-local": "5.0.0-beta.31",
-    "@workflow/world-vercel": "5.0.0-beta.33",
+    "@workflow/world-local": "5.0.0-beta.32",
+    "@workflow/world-vercel": "5.0.0-beta.34",
     "ai": "catalog:",
     "autoevals": "0.0.132",
     "chat": "4.34.0",
diff --git a/packages/eve/scripts/vendor-compiled/@workflow/core.mjs b/packages/eve/scripts/vendor-compiled/@workflow/core.mjs
index ecb4b1890..5b980369a 100644
--- a/packages/eve/scripts/vendor-compiled/@workflow/core.mjs
+++ b/packages/eve/scripts/vendor-compiled/@workflow/core.mjs
@@ -94,10 +94,41 @@ const copyDeclarations = createDeclarationCopier({
   },
 });
 
+// @workflow/core@5.0.0-beta.38 restored runtime world selection: its
+// `createWorld()` statically imports both first-party world packages. eve
+// never calls that factory — worlds are selected and wired explicitly at
+// build time — so those imports would only drag the local world into hosted
+// Vercel output (and the Vercel world into local-only builds). Stub them
+// inside core; each world package keeps its own vendored entry.
+const CORE_WORLD_FACTORY_STUB_ID = "\0eve-core-world-factory-stub";
+
+function stubCoreWorldFactories() {
+  return {
+    name: "eve:stub-core-world-factories",
+    resolveId(source, importer) {
+      if (source !== "@workflow/world-local" && source !== "@workflow/world-vercel") return null;
+      if (typeof importer !== "string") return null;
+      if (!importer.replaceAll("\\", "/").includes("/@workflow/core/")) return null;
+      return CORE_WORLD_FACTORY_STUB_ID;
+    },
+    load(id) {
+      if (id !== CORE_WORLD_FACTORY_STUB_ID) return null;
+      return [
+        "export function createWorld() {",
+        '  throw new Error("Unsupported in eve: @workflow/core createWorld(). ' +
+          'eve selects and wires the workflow world explicitly at build time.");',
+        "}",
+        "",
+      ].join("\n");
+    },
+  };
+}
+
 export default {
   packageName: "@workflow/core",
   compiledPath: "@workflow/core",
   chunkGroup: "workflow",
+  plugins: [stubCoreWorldFactories()],
   entries: [
     {
       outputPath: "index",
diff --git a/packages/eve/src/channel/types.ts b/packages/eve/src/channel/types.ts
index 564b47dfd..b21987e82 100644
--- a/packages/eve/src/channel/types.ts
+++ b/packages/eve/src/channel/types.ts
@@ -29,6 +29,12 @@ export interface CancelTurnInput {
 /** Result of requesting turn cancellation. Both statuses are successful. */
 export interface CancelTurnResult {
   readonly status: CancelTurnStatus;
+  /**
+   * For `no_active_turn`: the error class that classified the target as
+   * inactive, distinguishing "already finished" (`HookNotFoundError`) from a
+   * transiently unreachable cancel hook (`EntityConflictError`).
+   */
+  readonly reason?: string;
 }
 
 /** Identifies a session to transition permanently to a terminal state. */
diff --git a/packages/eve/src/execution/cancel-descendant-turns-step.test.ts b/packages/eve/src/execution/cancel-descendant-turns-step.test.ts
index b4a740ec9..9dbe9ac62 100644
--- a/packages/eve/src/execution/cancel-descendant-turns-step.test.ts
+++ b/packages/eve/src/execution/cancel-descendant-turns-step.test.ts
@@ -140,11 +140,11 @@ describe("cancelDescendantTurnsStep", () => {
       serializedContext: {},
       sessionState: createPendingState(),
     });
-    await vi.advanceTimersByTimeAsync(3_000);
+    await vi.advanceTimersByTimeAsync(10_000);
     await expect(cancellation).resolves.toBeUndefined();
 
     expect(requestWorkflowTurnCancellation).toHaveBeenCalledOnce();
-    expect(cancelRemoteAgentTurn).toHaveBeenCalledTimes(12);
+    expect(cancelRemoteAgentTurn).toHaveBeenCalledTimes(8);
     expect(error).toHaveBeenCalledWith(
       "[eve:execution.cancel-descendant-turns] failed to cancel local descendant turn",
       expect.objectContaining({ callId: "call-local", childSessionId: "local-child" }),
@@ -155,7 +155,34 @@ describe("cancelDescendantTurnsStep", () => {
     );
   });
 
+  it("warns loudly when a descendant cancel is never accepted", async () => {
+    vi.useFakeTimers();
+    vi.mocked(requestWorkflowTurnCancellation).mockResolvedValue({
+      reason: "EntityConflictError",
+      status: "no_active_turn",
+    });
+    const warn = vi.spyOn(console, "warn").mockImplementation(() => {});
+
+    const cancellation = cancelDescendantTurnsStep({
+      serializedContext: {},
+      sessionState: createPendingState({ includeRemote: false }),
+    });
+    await vi.advanceTimersByTimeAsync(10_000);
+    await expect(cancellation).resolves.toBeUndefined();
+
+    expect(requestWorkflowTurnCancellation).toHaveBeenCalledTimes(8);
+    expect(warn).toHaveBeenCalledWith(
+      "[eve:execution.cancel-descendant-turns] descendant cancel was never accepted; the child may run to completion",
+      expect.objectContaining({
+        childSessionId: "local-child",
+        finalStatus: "no_active_turn",
+        reason: "EntityConflictError",
+      }),
+    );
+  });
+
   it("treats pending batches from older deployments as having no descendants", async () => {
+    const warn = vi.spyOn(console, "warn").mockImplementation(() => {});
     const session = setPendingRuntimeActionBatch({
       actions: [localAction],
       event: { sequence: 0, stepIndex: 0, turnId: "turn_0" },
@@ -171,6 +198,11 @@ describe("cancelDescendantTurnsStep", () => {
     expect(requestWorkflowTurnCancellation).not.toHaveBeenCalled();
     expect(cancelRemoteAgentTurn).not.toHaveBeenCalled();
     expect(deserializeContext).not.toHaveBeenCalled();
+    // The skipped cancellation is observable, not silent.
+    expect(warn).toHaveBeenCalledWith(
+      "[eve:execution.cancel-descendant-turns] pending batch carries no child session ids; descendants cannot be cancelled",
+      expect.objectContaining({ sessionId: expect.any(String) }),
+    );
   });
 });
 
diff --git a/packages/eve/src/execution/cancel-descendant-turns-step.ts b/packages/eve/src/execution/cancel-descendant-turns-step.ts
index 854e0cb89..9924b7173 100644
--- a/packages/eve/src/execution/cancel-descendant-turns-step.ts
+++ b/packages/eve/src/execution/cancel-descendant-turns-step.ts
@@ -16,8 +16,12 @@ import type {
 } from "#runtime/actions/types.js";
 import type { RuntimeSubagentRegistry } from "#runtime/subagents/registry.js";
 
-const CANCEL_ATTEMPTS = 12;
-const CANCEL_RETRY_DELAY_MS = 250;
+// Retry through transient world contention (queue wakes, hook-claim
+// conflicts), then log loudly: a silently dropped cancel leaves the child
+// running to completion with no trace of why.
+const CANCEL_ATTEMPTS = 8;
+const CANCEL_RETRY_INITIAL_DELAY_MS = 250;
+const CANCEL_RETRY_MAX_DELAY_MS = 1_500;
 const log = createLogger("execution.cancel-descendant-turns");
 
 /** Cancels every successfully adopted child in the current pending batch. */
@@ -38,9 +42,20 @@ export async function cancelDescendantTurnsStep(input: {
     return;
   }
 
-  if (batch === undefined) return;
+  if (batch === undefined) {
+    log.warn("no pending batch found while cancelling descendants; nothing to cancel", {
+      sessionId: input.sessionState.sessionId,
+    });
+    return;
+  }
   const childSessionIds = batch.childSessionIds;
-  if (childSessionIds === undefined) return;
+  if (childSessionIds === undefined) {
+    log.warn("pending batch carries no child session ids; descendants cannot be cancelled", {
+      actionCount: batch.actions.length,
+      sessionId: input.sessionState.sessionId,
+    });
+    return;
+  }
 
   let remoteRegistry: Promise<RuntimeSubagentRegistry["subagentsByNodeId"]> | undefined;
   const getRemoteRegistry = () =>
@@ -75,10 +90,19 @@ async function cancelLocalDescendant(input: {
   readonly childSessionId: string;
 }): Promise<void> {
   try {
-    await requestCancellationWithRetry({
+    const final = await requestCancellationWithRetry({
       request: () => requestWorkflowTurnCancellation({ sessionId: input.childSessionId }),
       shouldRetryError: () => false,
     });
+    if (final.status !== "accepted") {
+      log.warn("descendant cancel was never accepted; the child may run to completion", {
+        callId: input.action.callId,
+        childSessionId: input.childSessionId,
+        finalStatus: final.status,
+        reason: final.reason,
+        subagentName: input.action.subagentName,
+      });
+    }
   } catch (error) {
     logError(log, "failed to cancel local descendant turn", error, {
       callId: input.action.callId,
@@ -101,10 +125,19 @@ async function cancelRemoteDescendant(input: {
       registry,
     });
 
-    await requestCancellationWithRetry({
+    const final = await requestCancellationWithRetry({
       request: () => cancelRemoteAgentTurn({ remote, sessionId: input.childSessionId }),
       shouldRetryError: isRetryableRemoteAgentCancelError,
     });
+    if (final.status !== "accepted") {
+      log.warn("remote descendant cancel was never accepted; the child may run to completion", {
+        callId: input.action.callId,
+        childSessionId: input.childSessionId,
+        finalStatus: final.status,
+        reason: final.reason,
+        remoteAgentName: input.action.remoteAgentName,
+      });
+    }
   } catch (error) {
     logError(log, "failed to cancel remote descendant turn", error, {
       callId: input.action.callId,
@@ -117,15 +150,21 @@ async function cancelRemoteDescendant(input: {
 async function requestCancellationWithRetry(input: {
   readonly request: () => Promise<CancelTurnResult>;
   readonly shouldRetryError: (error: unknown) => boolean;
-}): Promise<void> {
+}): Promise<CancelTurnResult> {
+  let delayMs = CANCEL_RETRY_INITIAL_DELAY_MS;
+  let lastResult: CancelTurnResult = { status: "no_active_turn" };
+
   for (let attempt = 1; attempt <= CANCEL_ATTEMPTS; attempt += 1) {
     try {
-      const result = await input.request();
-      if (result.status === "accepted" || attempt === CANCEL_ATTEMPTS) return;
+      lastResult = await input.request();
+      if (lastResult.status === "accepted" || attempt === CANCEL_ATTEMPTS) return lastResult;
     } catch (error) {
       if (!input.shouldRetryError(error) || attempt === CANCEL_ATTEMPTS) throw error;
     }
 
-    await new Promise((resolve) => setTimeout(resolve, CANCEL_RETRY_DELAY_MS));
+    await new Promise((resolve) => setTimeout(resolve, delayMs));
+    delayMs = Math.min(delayMs * 2, CANCEL_RETRY_MAX_DELAY_MS);
   }
+
+  return lastResult;
 }
diff --git a/packages/eve/src/execution/sandbox/bindings/vercel.test.ts b/packages/eve/src/execution/sandbox/bindings/vercel.test.ts
index 1a1f85928..38c23c880 100644
--- a/packages/eve/src/execution/sandbox/bindings/vercel.test.ts
+++ b/packages/eve/src/execution/sandbox/bindings/vercel.test.ts
@@ -6,6 +6,15 @@ import { SandboxTemplateNotProvisionedError } from "#public/definitions/sandbox-
 import { vercel } from "#public/sandbox/backends/vercel.js";
 import { createVercelSandbox } from "#execution/sandbox/bindings/vercel.js";
 
+// The credential fallback consults the developer's Vercel CLI auth and the
+// repo's `.vercel` project link; on a linked, logged-in machine it would
+// inject real project credentials into the asserted SDK calls.
+vi.mock("#compiled/@vercel/oidc/index.js", () => ({
+  getVercelOidcToken: vi.fn(async () => {
+    throw new Error("No ambient Vercel OIDC token in unit tests.");
+  }),
+}));
+
 function createMockCommandResult() {
   return {
     exitCode: 0,
diff --git a/packages/eve/src/execution/turn-cancellation-control.test.ts b/packages/eve/src/execution/turn-cancellation-control.test.ts
index cda4eb17b..731b53fd1 100644
--- a/packages/eve/src/execution/turn-cancellation-control.test.ts
+++ b/packages/eve/src/execution/turn-cancellation-control.test.ts
@@ -113,6 +113,50 @@ describe("createTurnCancellationControl", () => {
     expect(control!.signal.aborted).toBe(false);
   });
 
+  it("flips the signal in the same microtask that consumes the payload", async () => {
+    // A wake replays a journaled cancel and a completed step in one drain,
+    // payload first; the settle check reads `signal.aborted` one microtask
+    // later, so a `.then`-chained abort would lose to it.
+    let releasePayload!: (result: IteratorResult<unknown>) => void;
+    const firstRead = new Promise<IteratorResult<unknown>>((resolve) => {
+      releasePayload = resolve;
+    });
+    let delivered = false;
+    createHookMock.mockReturnValue({
+      token: "session-1:cancel",
+      getConflict: vi.fn(async () => null),
+      dispose: vi.fn(),
+      [Symbol.asyncIterator](): AsyncIterator<unknown> {
+        return {
+          next: () => {
+            if (delivered) return new Promise<IteratorResult<unknown>>(() => {});
+            delivered = true;
+            return firstRead;
+          },
+          return: vi.fn(async () => ({ done: true, value: undefined })),
+        };
+      },
+    });
+
+    const control = await createTurnCancellationControl({
+      expectedTurnId: "turn_0",
+      sessionId: "session-1",
+    });
+
+    let releaseStep!: () => void;
+    const step = new Promise<void>((resolve) => {
+      releaseStep = resolve;
+    });
+    const abortedAtStepContinuation = step.then(() => control!.signal.aborted);
+
+    // Journal order: the cancel payload resolves before the step result.
+    releasePayload({ done: false, value: {} });
+    releaseStep();
+
+    await expect(abortedAtStepContinuation).resolves.toBe(true);
+    await expect(control!.requested).resolves.toBe("cancel");
+  });
+
   it("disposes idempotently", async () => {
     const { dispose } = installCancelHook({});
 
diff --git a/packages/eve/src/execution/turn-cancellation-control.ts b/packages/eve/src/execution/turn-cancellation-control.ts
index 1869ce4f7..2451e821e 100644
--- a/packages/eve/src/execution/turn-cancellation-control.ts
+++ b/packages/eve/src/execution/turn-cancellation-control.ts
@@ -51,12 +51,13 @@ export async function createTurnCancellationControl(input: {
   }
 
   const controller = new AbortController();
-  // The durable abort fires in the read's continuation so its call site
-  // is reached deterministically on every replay.
-  const requested = consumeMatchingCancel(iterator, input.expectedTurnId).then(() => {
+  // The abort must fire inside the read continuation — not a chained
+  // `.then` — so the signal is already flipped when a same-drain
+  // continuation (the turn loop's settle check) reads it; one microtask
+  // later and an ordinary completion swallows the cancel.
+  const requested = consumeMatchingCancel(iterator, input.expectedTurnId, () => {
     controller.abort(new TurnCancelledError());
-    return "cancel" as const;
-  });
+  }).then(() => "cancel" as const);
 
   let disposed = false;
   return {
@@ -73,15 +74,20 @@ export async function createTurnCancellationControl(input: {
 }
 
 // Mismatched turn guards are consumed as no-ops; each read is durable,
-// so the skip sequence replays deterministically.
+// so the skip sequence replays deterministically. `onCancel` fires inside
+// the matching read's continuation (see the abort ordering note above).
 async function consumeMatchingCancel(
   iterator: AsyncIterator<TurnCancelPayload>,
   expectedTurnId: string,
+  onCancel: () => void,
 ): Promise<void> {
   while (true) {
     const next = await iterator.next();
     if (next.done) return await new Promise<never>(() => {});
-    if (matchesActiveTurn(next.value, expectedTurnId)) return;
+    if (matchesActiveTurn(next.value, expectedTurnId)) {
+      onCancel();
+      return;
+    }
   }
 }
 
diff --git a/packages/eve/src/execution/turn-cancellation.integration.test.ts b/packages/eve/src/execution/turn-cancellation.integration.test.ts
index 705bf08f7..857750b00 100644
--- a/packages/eve/src/execution/turn-cancellation.integration.test.ts
+++ b/packages/eve/src/execution/turn-cancellation.integration.test.ts
@@ -489,7 +489,10 @@ describe("turn cancellation integration", () => {
         // settled and its cancel hook swept, it reports the benign status.
         await waitForHookSweep(sessionCancelHookToken(run.runId));
         const session = createSession(run.runId, rawToken, workflowRuntime);
-        await expect(session.cancel()).resolves.toEqual({ status: "no_active_turn" });
+        await expect(session.cancel()).resolves.toEqual({
+          reason: "HookNotFoundError",
+          status: "no_active_turn",
+        });
 
         await waitForHook({ runId: run.runId }, { token: continuationToken });
         await resumeHook(continuationToken, {
diff --git a/packages/eve/src/execution/turn-workflow.test.ts b/packages/eve/src/execution/turn-workflow.test.ts
index 227743039..9f352ebd0 100644
--- a/packages/eve/src/execution/turn-workflow.test.ts
+++ b/packages/eve/src/execution/turn-workflow.test.ts
@@ -296,6 +296,46 @@ describe("turnWorkflow", () => {
     expect(resumeHookMock.mock.calls.filter((call) => call[1]?.kind === "turn-error")).toEqual([]);
   });
 
+  it("honors cancellation observed while a durable turn step returns", async () => {
+    const sessionState = createSessionState();
+    installInbox([], { cancelPayloads: [{}] });
+    vi.mocked(turnStep).mockImplementationOnce(async (stepInput) => {
+      await vi.waitFor(() => expect(stepInput.abortSignal?.aborted).toBe(true));
+      return {
+        action: "done",
+        output: "must not complete",
+        serializedContext: { state: "done" },
+        sessionState,
+      };
+    });
+
+    const { input } = createInput({
+      driverCapabilities: { cancelledTurnSettle: true, turnInbox: true },
+      sessionState,
+    });
+    await turnWorkflow(input);
+
+    expect(cancelDescendantTurnsStep).toHaveBeenCalledWith({
+      serializedContext: { state: "start" },
+      sessionState,
+    });
+    expect(resumeHookMock).toHaveBeenCalledWith("turn-token", {
+      action: {
+        cancelled: true,
+        kind: "park",
+        serializedContext: { state: "start" },
+        sessionState,
+      },
+      kind: "turn-result",
+    });
+    expect(resumeHookMock).not.toHaveBeenCalledWith(
+      "turn-token",
+      expect.objectContaining({
+        action: expect.objectContaining({ kind: "done" }),
+      }),
+    );
+  });
+
   it("runs uncancellable when the session cancel token is claimed by another run", async () => {
     const sessionState = createSessionState();
     installInbox([], { cancelConflict: { runId: "wrun_stale_prior_turn" } });
diff --git a/packages/eve/src/execution/turn-workflow.ts b/packages/eve/src/execution/turn-workflow.ts
index 62ceaf9df..e1250ff19 100644
--- a/packages/eve/src/execution/turn-workflow.ts
+++ b/packages/eve/src/execution/turn-workflow.ts
@@ -106,8 +106,18 @@ async function runTurnOwnedWorkflow(input: TurnWorkflowInput): Promise<void> {
 
     while (true) {
       const result = await turnStep(cursor.createStepInput(nextStepInput, cancellation?.signal));
+      const pendingActionKeys =
+        result.action === "dispatch-workflow-runtime-actions" || result.action === "park"
+          ? result.pendingRuntimeActionKeys
+          : undefined;
 
-      if (result.action === "cancelled") {
+      // A cancel observed while the step was returning must still win: the
+      // step may have missed the abort and completed normally. Pending
+      // runtime-action batches are exempt — their wait observes the signal.
+      if (
+        result.action === "cancelled" ||
+        (cancellation?.signal.aborted === true && pendingActionKeys === undefined)
+      ) {
         // No `canPark` check here: that gate rejects model-authored waits
         // (`next: null`) in task mode, whereas a cancelled turn parks by
         // design and its parkability was already established when the
@@ -137,11 +147,6 @@ async function runTurnOwnedWorkflow(input: TurnWorkflowInput): Promise<void> {
       // A pending runtime-action batch (model-driven `park` or dynamic-workflow
       // interrupt) is resolved in-line so the turn stays alive across the wait;
       // the two arms differ only in their dispatch path.
-      const pendingActionKeys =
-        result.action === "dispatch-workflow-runtime-actions" || result.action === "park"
-          ? result.pendingRuntimeActionKeys
-          : undefined;
-
       if (pendingActionKeys !== undefined) {
         await cursor.adopt(result);
         const dispatch =
diff --git a/packages/eve/src/execution/workflow-runtime.test.ts b/packages/eve/src/execution/workflow-runtime.test.ts
index 79346d5cc..207f90f10 100644
--- a/packages/eve/src/execution/workflow-runtime.test.ts
+++ b/packages/eve/src/execution/workflow-runtime.test.ts
@@ -169,19 +169,23 @@ describe("createWorkflowRuntime#cancelTurn", () => {
     expect(resumeHookMock).toHaveBeenCalledWith("session-1:cancel", {});
   });
 
-  it("maps missing and terminal targets to 'no_active_turn'", async () => {
+  it("maps missing and terminal targets to 'no_active_turn' with a classified reason", async () => {
     const { EntityConflictError, HookNotFoundError, RunExpiredError, WorkflowRunNotFoundError } =
       await import("#compiled/@workflow/errors/index.js");
     const errors = [
-      new HookNotFoundError("session-1:cancel"),
-      new WorkflowRunNotFoundError("turn-run"),
-      new RunExpiredError("turn already completed"),
-      new EntityConflictError("turn completed during cancellation"),
+      { error: new HookNotFoundError("session-1:cancel"), reason: "HookNotFoundError" },
+      { error: new WorkflowRunNotFoundError("turn-run"), reason: "WorkflowRunNotFoundError" },
+      { error: new RunExpiredError("turn already completed"), reason: "RunExpiredError" },
+      {
+        error: new EntityConflictError("turn completed during cancellation"),
+        reason: "EntityConflictError",
+      },
     ];
 
-    for (const error of errors) {
+    for (const { error, reason } of errors) {
       resumeHookMock.mockRejectedValueOnce(error);
       await expect(buildRuntime().cancelTurn({ sessionId: "session-1" })).resolves.toEqual({
+        reason,
         status: "no_active_turn",
       });
     }
diff --git a/packages/eve/src/execution/workflow-runtime.ts b/packages/eve/src/execution/workflow-runtime.ts
index d63ab146e..9711a203a 100644
--- a/packages/eve/src/execution/workflow-runtime.ts
+++ b/packages/eve/src/execution/workflow-runtime.ts
@@ -269,20 +269,20 @@ export async function requestWorkflowTurnCancellation(
     await resumeHook(sessionCancelHookToken(input.sessionId), payload);
     return { status: "accepted" };
   } catch (error) {
-    if (isInactiveCancelTarget(error)) {
-      return { status: "no_active_turn" };
+    const reason = classifyInactiveCancelTarget(error);
+    if (reason !== undefined) {
+      return { reason, status: "no_active_turn" };
     }
     throw error;
   }
 }
 
-function isInactiveCancelTarget(error: unknown): boolean {
-  return (
-    HookNotFoundError.is(error) ||
-    WorkflowRunNotFoundError.is(error) ||
-    RunExpiredError.is(error) ||
-    EntityConflictError.is(error)
-  );
+function classifyInactiveCancelTarget(error: unknown): string | undefined {
+  if (HookNotFoundError.is(error)) return "HookNotFoundError";
+  if (WorkflowRunNotFoundError.is(error)) return "WorkflowRunNotFoundError";
+  if (RunExpiredError.is(error)) return "RunExpiredError";
+  if (EntityConflictError.is(error)) return "EntityConflictError";
+  return undefined;
 }
 
 function isAlreadyTerminalSessionError(error: unknown): boolean {
diff --git a/packages/eve/src/internal/application/compiled-artifacts.ts b/packages/eve/src/internal/application/compiled-artifacts.ts
index 81114d440..4ce9c7e30 100644
--- a/packages/eve/src/internal/application/compiled-artifacts.ts
+++ b/packages/eve/src/internal/application/compiled-artifacts.ts
@@ -5,7 +5,6 @@ import { join } from "node:path";
 import type { CompileMetadata } from "#compiler/artifacts.js";
 import type { CompileAgentResult } from "#compiler/compile-agent.js";
 import { createCompiledModuleMapSource } from "#compiler/module-map.js";
-import { getWorldImport } from "@workflow/utils";
 import { stringifyEsmImportSpecifier } from "#internal/application/import-specifier.js";
 import {
   resolvePackageCompiledFilePath,
@@ -15,6 +14,7 @@ import { buildPackageUserAgent } from "#internal/user-agent.js";
 import type { AgentWorkflowWorldDefinition } from "#shared/agent-definition.js";
 import { readMaterializedAuthoredModuleIndex } from "#internal/materialized-authored-modules.js";
 import { usesParentDevelopmentWorkflowWorld } from "#internal/workflow/development-world-protocol.js";
+import { resolveWorkflowWorldImport } from "#internal/workflow/world-target.js";
 
 export type BuiltInWorkflowWorldTarget = "local" | "vercel";
 
@@ -313,7 +313,7 @@ export function createWorkflowWorldPluginSource(input: {
   defaultWorld: BuiltInWorkflowWorldTarget;
 }): string {
   const targetWorld = input.configuredWorld ?? input.defaultWorld;
-  const packageName = getWorldImport({ WORKFLOW_TARGET_WORLD: targetWorld });
+  const packageName = resolveWorkflowWorldImport(targetWorld);
   const wiring = resolveWorkflowWorldWiring(packageName);
   const workflowRuntimeImportSpecifier = resolvePackageCompiledFilePath(
     "src/compiled/@workflow/core/runtime.js",
diff --git a/packages/eve/src/internal/workflow/development-world-protocol.ts b/packages/eve/src/internal/workflow/development-world-protocol.ts
index 4756b84a6..8249cf56c 100644
--- a/packages/eve/src/internal/workflow/development-world-protocol.ts
+++ b/packages/eve/src/internal/workflow/development-world-protocol.ts
@@ -1,6 +1,5 @@
-import { getWorldImport } from "@workflow/utils";
-
 import type { AgentWorkflowWorldDefinition } from "#shared/agent-definition.js";
+import { resolveWorkflowWorldImport } from "#internal/workflow/world-target.js";
 
 export const DEVELOPMENT_WORKFLOW_WORLD_ROUTE = "/eve/v1/dev/internal/workflow-world";
 
@@ -15,10 +14,7 @@ export const DEVELOPMENT_WORKFLOW_WORLD_ROUTE = "/eve/v1/dev/internal/workflow-w
 export function usesParentDevelopmentWorkflowWorld(
   configuredWorld: AgentWorkflowWorldDefinition | undefined,
 ): boolean {
-  return (
-    getWorldImport({ WORKFLOW_TARGET_WORLD: configuredWorld ?? "local" }) ===
-    "@workflow/world-local"
-  );
+  return resolveWorkflowWorldImport(configuredWorld ?? "local") === "@workflow/world-local";
 }
 export const DEVELOPMENT_WORKFLOW_SECRET_ENV = "EVE_DEV_WORKFLOW_TRANSPORT_SECRET";
 export const DEVELOPMENT_WORKER_APP_ROOT_ENV = "EVE_DEV_WORKER_APP_ROOT";
diff --git a/packages/eve/src/internal/workflow/world-target.test.ts b/packages/eve/src/internal/workflow/world-target.test.ts
new file mode 100644
index 000000000..c740fbdb3
--- /dev/null
+++ b/packages/eve/src/internal/workflow/world-target.test.ts
@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+
+import { resolveWorkflowWorldImport } from "#internal/workflow/world-target.js";
+
+describe("resolveWorkflowWorldImport", () => {
+  it("maps the built-in world shorthands to their packages", () => {
+    expect(resolveWorkflowWorldImport("local")).toBe("@workflow/world-local");
+    expect(resolveWorkflowWorldImport("vercel")).toBe("@workflow/world-vercel");
+  });
+
+  it("passes custom world specifiers through unchanged", () => {
+    expect(resolveWorkflowWorldImport("@acme/world-redis")).toBe("@acme/world-redis");
+    expect(resolveWorkflowWorldImport("./relative/world.js")).toBe("./relative/world.js");
+  });
+});
diff --git a/packages/eve/src/internal/workflow/world-target.ts b/packages/eve/src/internal/workflow/world-target.ts
new file mode 100644
index 000000000..b9e297500
--- /dev/null
+++ b/packages/eve/src/internal/workflow/world-target.ts
@@ -0,0 +1,11 @@
+/**
+ * Maps a configured workflow world target to its package import specifier,
+ * mirroring the Workflow DevKit's `WORKFLOW_TARGET_WORLD` normalization:
+ * `"local"` and `"vercel"` are shorthands for the first-party world
+ * packages; anything else is already a specifier.
+ */
+export function resolveWorkflowWorldImport(targetWorld: string): string {
+  if (targetWorld === "local") return "@workflow/world-local";
+  if (targetWorld === "vercel") return "@workflow/world-vercel";
+  return targetWorld;
+}
diff --git a/packages/eve/test/scenarios/app-runtime-dependencies.scenario.test.ts b/packages/eve/test/scenarios/app-runtime-dependencies.scenario.test.ts
index 20be75bbe..8c8a032d2 100644
--- a/packages/eve/test/scenarios/app-runtime-dependencies.scenario.test.ts
+++ b/packages/eve/test/scenarios/app-runtime-dependencies.scenario.test.ts
@@ -847,11 +847,12 @@ describe("app runtime dependency tracing", () => {
     expect(vercelFunctionsSource).not.toContain("chokidar");
     expect(vercelFunctionsSource).not.toContain("[eve:dev]");
     expect(vercelFunctionsSource).not.toContain("rollup:reload");
-    // The world-local canary is its config env var, not its error-class
-    // names: the semantic-error catalog legitimately embeds names like
-    // `DataDirAccessError` as matcher strings without bundling any
-    // world-local code.
-    expect(vercelFunctionsSource).not.toContain("WORKFLOW_LOCAL_DATA_DIR");
+    // The world-local canary is its log prefix, not names other packages
+    // legitimately mention without bundling world-local code: the
+    // semantic-error catalog embeds error-class names like
+    // `DataDirAccessError`, and @workflow/core's runtime world factory
+    // (stubbed out at vendor time) names `WORKFLOW_LOCAL_DATA_DIR`.
+    expect(vercelFunctionsSource).not.toContain("[world-local]");
   }, 30_000);
 
   it("loads instrumentation runtime dependencies from hosted Vercel output", async () => {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index da0a62e02..d1381c7fd 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1150,26 +1150,26 @@ importers:
         specifier: 1.28.8
         version: 1.28.8
       '@workflow/core':
-        specifier: 5.0.0-beta.37
-        version: 5.0.0-beta.37(@opentelemetry/api@1.9.1)(supports-color@10.2.2)(ws@8.21.1(bufferutil@4.1.0))
+        specifier: 5.0.0-beta.38
+        version: 5.0.0-beta.38(@opentelemetry/api@1.9.1)(supports-color@10.2.2)(ws@8.21.1(bufferutil@4.1.0))
       '@workflow/errors':
-        specifier: 5.0.0-beta.13
-        version: 5.0.0-beta.13
+        specifier: 5.0.0-beta.14
+        version: 5.0.0-beta.14
       '@workflow/serde':
         specifier: 5.0.0-beta.2
         version: 5.0.0-beta.2
       '@workflow/utils':
-        specifier: 5.0.0-beta.7
-        version: 5.0.0-beta.7
+        specifier: 5.0.0-beta.8
+        version: 5.0.0-beta.8
       '@workflow/world':
         specifier: 5.0.0-beta.23
         version: 5.0.0-beta.23
       '@workflow/world-local':
-        specifier: 5.0.0-beta.31
-        version: 5.0.0-beta.31(@opentelemetry/api@1.9.1)
+        specifier: 5.0.0-beta.32
+        version: 5.0.0-beta.32(@opentelemetry/api@1.9.1)
       '@workflow/world-vercel':
-        specifier: 5.0.0-beta.33
-        version: 5.0.0-beta.33(@opentelemetry/api@1.9.1)
+        specifier: 5.0.0-beta.34
+        version: 5.0.0-beta.34(@opentelemetry/api@1.9.1)
       ai:
         specifier: 'catalog:'
         version: 7.0.38(zod@4.4.3)
@@ -7282,16 +7282,16 @@ packages:
   '@webgpu/types@0.1.71':
     resolution: {integrity: sha512-mMy8/ODcKhab808co15eW+yN+HgXoQxRQHTiBV9Mrvl1r0ufnid7YOcI+gi4eUWSWl9ezD6TW2KXccrL8HCh2A==}
 
-  '@workflow/core@5.0.0-beta.37':
-    resolution: {integrity: sha512-QaBWdRXpQj2dSMkl7sjsTL3TNTfo2yDcXcLd8rFJ6u6By7xj5rC4nu4qsk8Cn6f13Dh9jrQTXGbDrDVZaeLgpQ==}
+  '@workflow/core@5.0.0-beta.38':
+    resolution: {integrity: sha512-jXQFXQ6o5Px0UNzQwH7eCnNeR9XeVIYIjI99PoMmgXcZZ+3828/ij/jvsMI+5xW7yo8IJMm24gl8rxsVI0tngQ==}
     peerDependencies:
       '@opentelemetry/api': '1'
     peerDependenciesMeta:
       '@opentelemetry/api':
         optional: true
 
-  '@workflow/errors@5.0.0-beta.13':
-    resolution: {integrity: sha512-xRiG9MEunLxkb7hw7n17+/cKKH4QfFvnQly4cAF2ImxPRDnL0HvWot9eHOPS3S41LEyZ/LSs/sYrIN07XUZbgw==}
+  '@workflow/errors@5.0.0-beta.14':
+    resolution: {integrity: sha512-1RwF7LG7JbIp78zD+eb1A8ifDacI12wzpdMAFbzMODc/Ok0u+1IXbT1DIVKLtBLnUOPrWLxnXBYDnkvkvG9tAw==}
 
   '@workflow/serde@4.1.0':
     resolution: {integrity: sha512-pav4F2BoirECWR7Nf1TKt+2eETcBj7jj4cBefQ8VXQCA6NPkaKeLfj/zMgi+3zYV5ZIBT4GuUiphsj0/b9hPQQ==}
@@ -7302,19 +7302,19 @@ packages:
   '@workflow/serde@5.0.0-beta.2':
     resolution: {integrity: sha512-INB+FcEKQkkFZa+s53sEMTNRFiBa2g9vzjsNuEDagvWxtI0t/cnCyoc57i7kS7nj+3/vGeRjO4Yn5ccbT0hyBQ==}
 
-  '@workflow/utils@5.0.0-beta.7':
-    resolution: {integrity: sha512-3vDiA8xea4USslIbz6m9HAhxDhvqLbETaXFxTNqVm/m8eji0rLKwnfF6JLaH0Qr1GsovysoOUlvyibokkNHZrg==}
+  '@workflow/utils@5.0.0-beta.8':
+    resolution: {integrity: sha512-dDiQ/LT05g9HyOicqWNNX/Gw/fmO7Ma2kZ+ddUXXpm/EFTMRS9eiI69suSe1+1NnhMzdV6ObI8wrO5lvQqPIbg==}
 
-  '@workflow/world-local@5.0.0-beta.31':
-    resolution: {integrity: sha512-Z9nq5lzjXnig4ONfLnVwTqx6EbxJjhTB5SBKT8ERcKe6/SFm30s1BIZ03bZBJox2Y4jJAgsNgvey29xWGnzMAg==}
+  '@workflow/world-local@5.0.0-beta.32':
+    resolution: {integrity: sha512-D8kb1IHHrkDbKnpUw3cqZnlkis3YCYPF2BoV6vWpGUGTeSGsnTZjMsrqsh5luKeZSUqK5BCO/YC27S9AdkBO0w==}
     peerDependencies:
       '@opentelemetry/api': '1'
     peerDependenciesMeta:
       '@opentelemetry/api':
         optional: true
 
-  '@workflow/world-vercel@5.0.0-beta.33':
-    resolution: {integrity: sha512-6MWaWw85145AInDBYql33XPETAjrOvu40wJYje/JwJwkFtOrGSx2B2vjbNxscafsN9TIZYUCRdK53spcqsMNzg==}
+  '@workflow/world-vercel@5.0.0-beta.34':
+    resolution: {integrity: sha512-bSBxUcs90wbhY8NlZYojoPAL7UwDuiTxr1R6eCb3ZCHCly5pTFXnkMIsM2hScPFM6ea/KImMl1KQVJc6OCPjIQ==}
     peerDependencies:
       '@opentelemetry/api': '1'
     peerDependenciesMeta:
@@ -21035,19 +21035,19 @@ snapshots:
 
   '@webgpu/types@0.1.71': {}
 
-  '@workflow/core@5.0.0-beta.37(@opentelemetry/api@1.9.1)(supports-color@10.2.2)(ws@8.21.1(bufferutil@4.1.0))':
+  '@workflow/core@5.0.0-beta.38(@opentelemetry/api@1.9.1)(supports-color@10.2.2)(ws@8.21.1(bufferutil@4.1.0))':
     dependencies:
       '@aws-sdk/credential-provider-web-identity': 3.972.49
       '@jridgewell/trace-mapping': 0.3.31
       '@standard-schema/spec': 1.0.0
       '@types/ms': 2.1.0
       '@vercel/functions': 3.7.5(@aws-sdk/credential-provider-web-identity@3.972.49)(ws@8.21.1(bufferutil@4.1.0))
-      '@workflow/errors': 5.0.0-beta.13
+      '@workflow/errors': 5.0.0-beta.14
       '@workflow/serde': 5.0.0-beta.2
-      '@workflow/utils': 5.0.0-beta.7
+      '@workflow/utils': 5.0.0-beta.8
       '@workflow/world': 5.0.0-beta.23
-      '@workflow/world-local': 5.0.0-beta.31(@opentelemetry/api@1.9.1)
-      '@workflow/world-vercel': 5.0.0-beta.33(@opentelemetry/api@1.9.1)
+      '@workflow/world-local': 5.0.0-beta.32(@opentelemetry/api@1.9.1)
+      '@workflow/world-vercel': 5.0.0-beta.34(@opentelemetry/api@1.9.1)
       debug: 4.4.3(supports-color@10.2.2)
       devalue: 5.8.1
       ms: 2.1.3
@@ -21062,9 +21062,9 @@ snapshots:
       - supports-color
       - ws
 
-  '@workflow/errors@5.0.0-beta.13':
+  '@workflow/errors@5.0.0-beta.14':
     dependencies:
-      '@workflow/utils': 5.0.0-beta.7
+      '@workflow/utils': 5.0.0-beta.8
       ms: 2.1.3
 
   '@workflow/serde@4.1.0': {}
@@ -21073,15 +21073,15 @@ snapshots:
 
   '@workflow/serde@5.0.0-beta.2': {}
 
-  '@workflow/utils@5.0.0-beta.7':
+  '@workflow/utils@5.0.0-beta.8':
     dependencies:
       ms: 2.1.3
 
-  '@workflow/world-local@5.0.0-beta.31(@opentelemetry/api@1.9.1)':
+  '@workflow/world-local@5.0.0-beta.32(@opentelemetry/api@1.9.1)':
     dependencies:
       '@vercel/queue': 0.4.0(@opentelemetry/api@1.9.1)
-      '@workflow/errors': 5.0.0-beta.13
-      '@workflow/utils': 5.0.0-beta.7
+      '@workflow/errors': 5.0.0-beta.14
+      '@workflow/utils': 5.0.0-beta.8
       '@workflow/world': 5.0.0-beta.23
       async-sema: 3.1.1
       ulid: 3.0.2
@@ -21090,11 +21090,11 @@ snapshots:
     optionalDependencies:
       '@opentelemetry/api': 1.9.1
 
-  '@workflow/world-vercel@5.0.0-beta.33(@opentelemetry/api@1.9.1)':
+  '@workflow/world-vercel@5.0.0-beta.34(@opentelemetry/api@1.9.1)':
     dependencies:
       '@vercel/oidc': 3.2.0
       '@vercel/queue': 0.4.0(@opentelemetry/api@1.9.1)
-      '@workflow/errors': 5.0.0-beta.13
+      '@workflow/errors': 5.0.0-beta.14
       '@workflow/world': 5.0.0-beta.23
       cbor-x: 1.6.0
       ulid: 3.0.2