diff --git a/docs/operations/adapter-remediation-ledger.md b/docs/operations/adapter-remediation-ledger.md
index 99be2dc..8884805 100644
--- a/docs/operations/adapter-remediation-ledger.md
+++ b/docs/operations/adapter-remediation-ledger.md
@@ -93,8 +93,8 @@ Rollout state starts at `NOT_STARTED`; documented-unimplemented items start at
 | STO-03 | Public cache not composed | `corepack pnpm exec vitest run tests/unit/public-response-cache.test.ts` | `fix: make public cache staging repairable` | `FIXED_NOT_RELEASED` | composition rejection of an existing policy | Red 4 cases across STO-03..05 → green 21/21; `check:types` PASS; `check:browser-file-storage-boundaries` PASS; `lint` PASS |
 | STO-04 | Public cache not composed | `corepack pnpm exec vitest run tests/unit/public-response-cache.test.ts` | `fix: make public cache staging repairable` | `FIXED_NOT_RELEASED` | restage loop or bandwidth spike | — |
 | STO-05 | Public cache not composed | `corepack pnpm exec vitest run tests/unit/public-response-cache.test.ts` | `fix: make public cache staging repairable` | `FIXED_NOT_RELEASED` | activation permitted without required capability | — |
-| STO-06 | IndexedDB maintenance | `corepack pnpm exec vitest run tests/unit/indexeddb-maintenance.test.ts` | — | `NOT_STARTED` | migration checkpoint stall | — |
-| STO-07 | OPFS worker protocol | `corepack pnpm exec vitest run tests/unit/opfs-worker-runtime.test.ts` | — | `NOT_STARTED` | page/worker `INCOMPATIBLE` spike | — |
+| STO-06 | IndexedDB maintenance | `corepack pnpm exec vitest run tests/unit/indexeddb-maintenance.test.ts` | `fix: bound migration commits and version the OPFS worker protocol` | `FIXED_NOT_RELEASED` | migration checkpoint stall | Red commit-phase deadline case → green 13/13; the monotonic budget is re-checked before each record's first write, a started record still finishes atomically, and a clock failure aborts the transaction |
+| STO-07 | OPFS worker protocol | `corepack pnpm exec vitest run tests/unit/opfs-worker-runtime.test.ts` | `fix: bound migration commits and version the OPFS worker protocol` | `FIXED_NOT_RELEASED` | page/worker `INCOMPATIBLE` spike | Green 23/23 across the OPFS suites; every envelope carries `OPFS_WORKER_PROTOCOL_VERSION = 2` and the response echoes its request kind, with a strict failure-shape decoder. A kind or version mismatch closes as `UNSUPPORTED` — the closed taxonomy has no `INCOMPATIBLE` code and none was invented |
 | STO-08 | Hypothesis; browser characterization required | `corepack pnpm exec playwright test --config playwright.capabilities.config.ts tests/browser-capabilities/browser-files.spec.ts` | none (source unchanged) | `UNVERIFIED` | n/a until characterized | chromium 2/2 PASS; webkit could not launch (`libevent-2.1-7t64`, `libavif16` missing — environmental). The existing spec does not exercise `Window.showOpenFilePicker`/`showSaveFilePicker`, which need a user gesture and a native dialog, so the receiver-binding hypothesis is **neither reproduced nor refuted**. No `SystemPickerHost` was introduced: the plan forbids implementing an uncharacterized hypothesis as a defect. |
 | GAP-01 | Documented unimplemented (VD-15) | promotion evidence, not a red test | — | `PROMOTION_BLOCKED` | n/a | — |
 | GAP-02 | Documented unimplemented (VD-15) | promotion evidence, not a red test | — | `PROMOTION_BLOCKED` | n/a | — |
@@ -148,7 +148,7 @@ Rollout state starts at `NOT_STARTED`; documented-unimplemented items start at
 | SW-07 | Composed when capability selected | `corepack pnpm exec vitest run tests/unit/service-worker-runtime.test.ts` | — | `NOT_STARTED` | activation blocked with zero clients | — |
 | SW-08 | Composed when capability selected | `corepack pnpm exec vitest run tests/unit/service-worker-runtime.test.ts` | — | `NOT_STARTED` | per-client failure escalation | — |
 | SW-09 | Composed when capability selected | `corepack pnpm exec vitest run tests/unit/service-worker-runtime.test.ts` | — | `NOT_STARTED` | late install work observed | — |
-| SW-10 | Protocol V2 migration | `corepack pnpm exec vitest run tests/unit/service-worker-runtime.test.ts` | — | `NOT_STARTED` | V1/V2 mismatch fail-close | — |
+| SW-10 | Protocol V2 migration | `corepack pnpm exec vitest run tests/unit/service-worker-runtime.test.ts` | — | `DEFERRED_TO_MIGRATION` | V1/V2 mismatch fail-close | Not closed here. Full-identity protocol V2 is an expand → dual-read → old-writer drain → contract deployment that spans releases; the prerequisite shared manifest codec and canonical digest landed with SW-05. |
 | WP-01 | Web Push `NOT_SELECTED` | `corepack pnpm exec vitest run tests/unit/web-push-fence-store.test.ts` | `fix: bind Web Push mutations to exact authority` | `FIXED_NOT_RELEASED` | CAS receipt rejection | Red stale/skipped/huge revision receipts → green; write and remove share one exact-next-revision validator |
 | WP-02 | Web Push `NOT_SELECTED` | `corepack pnpm exec vitest run tests/unit/web-push-fence-store.test.ts` | — | `DEFERRED_TO_MIGRATION` | `RECONCILIATION_REQUIRED` backlog | Deferred to the Task 16 versioned-migration PR: `MUTATION_OUTCOME_UNKNOWN` and the `RECONCILIATION_REQUIRED` lifecycle are part of the same wire/data migration as WP-03. |
 | WP-03 | Web Push `NOT_SELECTED` | `corepack pnpm exec vitest run tests/unit/web-push-subscription-adapter.test.ts` | — | `DEFERRED_TO_MIGRATION` | backend receipt mismatch | Deferred to the Task 16 versioned-migration PR: the V2 receipt requires server request-shape negotiation before a client rollout. |
diff --git a/src/adapters/storage/indexeddb/indexeddb-maintenance.ts b/src/adapters/storage/indexeddb/indexeddb-maintenance.ts
index 1e8745f..2667384 100644
--- a/src/adapters/storage/indexeddb/indexeddb-maintenance.ts
+++ b/src/adapters/storage/indexeddb/indexeddb-maintenance.ts
@@ -972,6 +972,7 @@ export function createIndexedDbMaintenance<WireValue>(
     prepared: readonly PreparedRecord<WireValue>[],
     scan: ScanBatch,
     budgetExhausted: boolean,
+    deadline: number,
     signal: AbortSignal | undefined,
   ): Promise<
     BrowserDataResult<IndexedDbMaintenanceBatchReceipt>
@@ -1048,6 +1049,22 @@ export function createIndexedDbMaintenance<WireValue>(
             finishWithCheckpoint();
             return;
           }
+          // STO-06. The commit chain runs entirely inside IndexedDB callbacks,
+          // so without this check up to `maxRows` records keep executing past
+          // the caller's invocation deadline. The budget is only ever checked
+          // before a record's first write, so a started record still finishes
+          // atomically and the checkpoint stays exactly at the last safe key.
+          const currentTime = clock();
+          if (!currentTime.ok) {
+            // A broken clock aborts rather than committing an unbounded batch.
+            context.fail(currentTime);
+            return;
+          }
+          if (currentTime.value >= deadline) {
+            budgetExhausted = true;
+            finishWithCheckpoint();
+            return;
+          }
           let request: IDBRequest<unknown>;
           try {
             request = records.get(preparedRecord.source.key);
@@ -1337,6 +1354,7 @@ export function createIndexedDbMaintenance<WireValue>(
         prepared.value.records,
         scan.value,
         prepared.value.budgetExhausted,
+        deadline,
         input.signal,
       );
       return observeResult(
diff --git a/src/adapters/storage/opfs/opfs-worker-client.ts b/src/adapters/storage/opfs/opfs-worker-client.ts
index ad5e70d..696d58f 100644
--- a/src/adapters/storage/opfs/opfs-worker-client.ts
+++ b/src/adapters/storage/opfs/opfs-worker-client.ts
@@ -14,6 +14,9 @@ import {
   browserDataSuccess,
 } from "../../browser-file-storage/result.ts";
 import type { OpfsRuntimePolicy } from "./opfs-policy.ts";
+import {
+  OPFS_WORKER_PROTOCOL_VERSION,
+} from "./opfs-worker-protocol.ts";
 import type {
   AbortPreparedPutRequest,
   OpfsWorkerGateway,
@@ -51,6 +54,7 @@ export type OwnedOpfsWorkerClient = Readonly<{
 }>;
 
 type PendingRequest = Readonly<{
+  expectedKind: OpfsWorkerRequest["kind"];
   resolve: (response: OpfsWorkerResponse) => void;
   reject: (error: OpfsRpcError) => void;
   timeout: ReturnType<typeof setTimeout>;
@@ -93,6 +97,14 @@ export function createOpfsWorkerGateway(
     pending.delete(event.data.requestId);
     clearTimeout(request.timeout);
     request.removeAbortListener();
+    if (event.data.kind !== request.expectedKind) {
+      // STO-07. A reply for a different operation is a protocol breach, not a
+      // value: close it as INCOMPATIBLE instead of decoding it.
+      // UNSUPPORTED is the closed-taxonomy code for "this runtime
+      // cannot serve this"; no new failure code is invented.
+      request.reject(new OpfsRpcError("UNSUPPORTED"));
+      return;
+    }
     request.resolve(event.data);
   };
   const onWorkerFailure = (): void => {
@@ -121,7 +133,11 @@ export function createOpfsWorkerGateway(
     ) {
       throw new OpfsRpcError("UNAVAILABLE");
     }
-    const message = { ...request, requestId } as OpfsWorkerRequest;
+    const message = {
+      ...request,
+      requestId,
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+    } as OpfsWorkerRequest;
 
     return await new Promise<OpfsWorkerResponse>((resolve, reject) => {
       const abort = (): void => {
@@ -141,6 +157,9 @@ export function createOpfsWorkerGateway(
         reject(new OpfsRpcError("UNAVAILABLE"));
       }, dependencies.policy.rpcTimeoutMs);
       pending.set(requestId, {
+        // STO-07. The expected kind is stored so a reply for a different
+        // operation can never satisfy this request.
+        expectedKind: request.kind,
         resolve,
         reject,
         timeout,
@@ -677,13 +696,35 @@ function parseOrphanDeleteResult(
   return value as OpfsOrphanDeleteResult;
 }
 
+/**
+ * STO-07. A response is only admitted when it carries the negotiated protocol
+ * version, echoes a known request kind and, on failure, a closed failure code.
+ * Accepting `{requestId, ok}` alone let a malformed or cross-release reply be
+ * decoded as a value of the wrong shape.
+ */
 function isWorkerResponse(value: unknown): value is OpfsWorkerResponse {
+  if (
+    !value ||
+    typeof value !== "object" ||
+    !("requestId" in value) ||
+    typeof value.requestId !== "string" ||
+    !("ok" in value) ||
+    typeof value.ok !== "boolean" ||
+    !("protocolVersion" in value) ||
+    value.protocolVersion !== OPFS_WORKER_PROTOCOL_VERSION ||
+    !("kind" in value) ||
+    typeof value.kind !== "string"
+  ) {
+    return false;
+  }
+  if (value.ok) return true;
+  const failure = (value as { failure?: unknown }).failure;
   return Boolean(
-    value &&
-      typeof value === "object" &&
-      "requestId" in value &&
-      typeof value.requestId === "string" &&
-      "ok" in value &&
-      typeof value.ok === "boolean",
+    failure &&
+      typeof failure === "object" &&
+      "code" in failure &&
+      typeof (failure as { code?: unknown }).code === "string" &&
+      "retryable" in failure &&
+      typeof (failure as { retryable?: unknown }).retryable === "boolean",
   );
 }
diff --git a/src/adapters/storage/opfs/opfs-worker-protocol.ts b/src/adapters/storage/opfs/opfs-worker-protocol.ts
index 7f51ddd..6dccaa9 100644
--- a/src/adapters/storage/opfs/opfs-worker-protocol.ts
+++ b/src/adapters/storage/opfs/opfs-worker-protocol.ts
@@ -14,13 +14,27 @@ import type {
   TransferProgress,
 } from "../../../application/ports/browser-file-storage/shared.ts";
 
+/**
+ * STO-07. Every request and response carries the protocol version and the
+ * response echoes its request kind, so a page/worker release mismatch or a
+ * malformed reply closes as `INCOMPATIBLE` instead of being decoded as a
+ * successful value of the wrong shape.
+ */
+export const OPFS_WORKER_PROTOCOL_VERSION = 2 as const;
+
+export type OpfsWorkerRequestEnvelope = Readonly<{
+  protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
+}>;
+
 export type OpfsWorkerRequest =
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "CAPABILITIES";
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "BEGIN_PUT";
       transactionId: string;
       scope: OpfsStorageScope;
@@ -36,6 +50,7 @@ export type OpfsWorkerRequest =
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "APPEND_CHUNK";
       scope: OpfsStorageScope;
       transactionId: string;
@@ -44,12 +59,14 @@ export type OpfsWorkerRequest =
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "FINISH_PUT";
       scope: OpfsStorageScope;
       transactionId: string;
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "ABORT_PUT";
       scope: OpfsStorageScope;
       transactionId: string;
@@ -57,17 +74,20 @@ export type OpfsWorkerRequest =
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "VERIFY_OBJECT";
       preparedObject: OpfsPreparedObject;
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "READ_CHUNK";
       preparedObject: OpfsPreparedObject;
       sequence: number;
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "REMOVE_OBJECT";
       scope: OpfsStorageScope;
       objectId: string;
@@ -75,6 +95,7 @@ export type OpfsWorkerRequest =
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "CLEANUP_TRANSACTION";
       scope: OpfsStorageScope;
       transactionId: string;
@@ -87,12 +108,14 @@ export type OpfsWorkerRequest =
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "FINALIZE_PUT";
       transactionId: string;
       preparedObject: OpfsPreparedObject;
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "LIST_ORPHAN_CANDIDATES";
       scope: OpfsStorageScope;
       olderThanEpochMs: number;
@@ -100,6 +123,7 @@ export type OpfsWorkerRequest =
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
       kind: "DELETE_ORPHAN_CHUNK";
       scope: OpfsStorageScope;
       digestHex: string;
@@ -109,7 +133,7 @@ export type OpfsWorkerRequest =
 export type OpfsWorkerRequestBody =
   OpfsWorkerRequest extends infer Request
     ? Request extends OpfsWorkerRequest
-      ? Omit<Request, "requestId">
+      ? Omit<Request, "requestId" | "protocolVersion">
       : never
     : never;
 
@@ -132,6 +156,8 @@ export type OpfsOrphanDeleteResult = Readonly<{
 export type OpfsWorkerResponse =
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
+      kind: OpfsWorkerRequest["kind"];
       ok: true;
       value?:
         | OpfsCapabilities
@@ -144,6 +170,8 @@ export type OpfsWorkerResponse =
     }>
   | Readonly<{
       requestId: string;
+      protocolVersion: typeof OPFS_WORKER_PROTOCOL_VERSION;
+      kind: OpfsWorkerRequest["kind"];
       ok: false;
       failure: OpfsWorkerFailure;
     }>;
diff --git a/src/adapters/storage/opfs/opfs-worker-runtime.ts b/src/adapters/storage/opfs/opfs-worker-runtime.ts
index 733b4b6..3607249 100644
--- a/src/adapters/storage/opfs/opfs-worker-runtime.ts
+++ b/src/adapters/storage/opfs/opfs-worker-runtime.ts
@@ -15,6 +15,9 @@ import {
   isValidOpfsStorageScope,
   type OpfsRuntimePolicy,
 } from "./opfs-policy.ts";
+import {
+  OPFS_WORKER_PROTOCOL_VERSION,
+} from "./opfs-worker-protocol.ts";
 import type {
   OpfsOrphanCandidateBatch,
   OpfsOrphanDeleteResult,
@@ -202,18 +205,23 @@ export function createOpfsWorkerRuntime(
         }
         switch (request.kind) {
           case "CAPABILITIES":
-            return success(request.requestId, capabilities);
+            return success(request.requestId, request.kind, capabilities);
           case "BEGIN_PUT":
             await beginPut(request);
-            return success(request.requestId);
+            return success(request.requestId, request.kind);
           case "APPEND_CHUNK":
             await appendChunk(request);
-            return success(request.requestId);
+            return success(request.requestId, request.kind);
           case "FINISH_PUT":
-            return success(request.requestId, await finishPut(request));
+            return success(
+              request.requestId,
+              request.kind,
+              await finishPut(request),
+            );
           case "ABORT_PUT":
             return success(
               request.requestId,
+              request.kind,
               await abortPut(
                 request.scope,
                 request.transactionId,
@@ -223,11 +231,13 @@ export function createOpfsWorkerRuntime(
           case "VERIFY_OBJECT":
             return success(
               request.requestId,
+              request.kind,
               await verifyObject(request.preparedObject),
             );
           case "READ_CHUNK":
             return success(
               request.requestId,
+              request.kind,
               await readVerifiedChunk(
                 request.preparedObject,
                 request.sequence,
@@ -239,10 +249,11 @@ export function createOpfsWorkerRuntime(
               request.objectId,
               request.generation,
             );
-            return success(request.requestId);
+            return success(request.requestId, request.kind);
           case "CLEANUP_TRANSACTION":
             return success(
               request.requestId,
+              request.kind,
               await cleanupTransaction(
                 request.scope,
                 request.transactionId,
@@ -255,10 +266,11 @@ export function createOpfsWorkerRuntime(
               request.transactionId,
               request.preparedObject,
             );
-            return success(request.requestId);
+            return success(request.requestId, request.kind);
           case "LIST_ORPHAN_CANDIDATES":
             return success(
               request.requestId,
+              request.kind,
               await listOrphanCandidates(
                 request.scope,
                 request.olderThanEpochMs,
@@ -268,6 +280,7 @@ export function createOpfsWorkerRuntime(
           case "DELETE_ORPHAN_CHUNK":
             return success(
               request.requestId,
+              request.kind,
               await deleteOrphanChunk(
                 request.scope,
                 request.digestHex,
@@ -1747,6 +1760,7 @@ function isPreparedObjectSafe(
 
 function success(
   requestId: string,
+  kind: OpfsWorkerRequest["kind"],
   value?: OpfsWorkerResponse extends infer _Response
     ?
         | OpfsCapabilities
@@ -1759,15 +1773,33 @@ function success(
     : never,
 ): OpfsWorkerResponse {
   return value === undefined
-    ? { requestId, ok: true }
-    : { requestId, ok: true, value };
+    ? {
+        requestId,
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+        kind,
+        ok: true,
+      }
+    : {
+        requestId,
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+        kind,
+        ok: true,
+        value,
+      };
 }
 
 function failure(
   requestId: string,
   workerFailure: OpfsWorkerFailure,
+  kind: OpfsWorkerRequest["kind"] = "CAPABILITIES",
 ): OpfsWorkerResponse {
-  return { requestId, ok: false, failure: workerFailure };
+  return {
+    requestId,
+    protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+    kind,
+    ok: false,
+    failure: workerFailure,
+  };
 }
 
 function mapRuntimeFailure(error: unknown): OpfsWorkerFailure {
@@ -1829,7 +1861,10 @@ function isWorkerRequest(value: unknown): value is OpfsWorkerRequest {
     hasRequestId(value) &&
       "kind" in value &&
       typeof value.kind === "string" &&
-      WORKER_REQUEST_KINDS.has(value.kind),
+      WORKER_REQUEST_KINDS.has(value.kind) &&
+      // STO-07. A page from another release must not be served.
+      "protocolVersion" in value &&
+      value.protocolVersion === OPFS_WORKER_PROTOCOL_VERSION,
   );
 }
 
diff --git a/tests/unit/indexeddb-maintenance.test.ts b/tests/unit/indexeddb-maintenance.test.ts
index fa3e525..248efd1 100644
--- a/tests/unit/indexeddb-maintenance.test.ts
+++ b/tests/unit/indexeddb-maintenance.test.ts
@@ -596,6 +596,37 @@ describe("IndexedDB bounded codec maintenance", () => {
     });
   });
 
+  it("stops codec migration commit at the cooperative deadline", async () => {
+    const memory = new MemoryIndexedDbFactory();
+    await prepareSchema(memory);
+    seedLegacy(memory, "row-a", "first");
+    seedLegacy(memory, "row-b", "second");
+    const policy = defaultPolicy();
+    // STO-06. The clock only advances past the deadline once the commit
+    // transaction is already open, so the stop must happen inside the commit
+    // chain rather than before transform.
+    let calls = 0;
+    const maintenance = createMaintenance(memory, policy, {
+      now: () => {
+        calls += 1;
+        // Scan, prepare and the first commit record stay inside the budget.
+        return calls <= 6 ? 0 : 5_000;
+      },
+    });
+
+    const result = await maintenance.migrateCodecBatch({
+      maxRows: 10,
+      maxDurationMs: 1_000,
+    });
+
+    expect(result.ok).toBe(true);
+    if (!result.ok) return;
+    // The batch is incomplete and says so; it never claims a full pass.
+    expect(result.value.state).toBe("MORE");
+    expect(result.value.budgetExhausted).toBe(true);
+    expect(result.value.checkpointedRows).toBeLessThan(2);
+  });
+
   it("fails closed when a historical payload cannot be transformed", async () => {
     const memory = new MemoryIndexedDbFactory();
     await prepareSchema(memory);
diff --git a/tests/unit/opfs-worker-runtime.test.ts b/tests/unit/opfs-worker-runtime.test.ts
index 8280b00..6d46af5 100644
--- a/tests/unit/opfs-worker-runtime.test.ts
+++ b/tests/unit/opfs-worker-runtime.test.ts
@@ -15,6 +15,7 @@ import {
   createOpfsWorkerGateway,
   type OpfsWorkerLike,
 } from "../../src/adapters/storage/opfs/opfs-worker-client.ts";
+import { OPFS_WORKER_PROTOCOL_VERSION } from "../../src/adapters/storage/opfs/opfs-worker-protocol.ts";
 import type {
   OpfsWorkerRequest,
   OpfsWorkerResponse,
@@ -181,6 +182,7 @@ function beginRequest(
 ): OpfsWorkerRequest {
   return {
     requestId,
+    protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
     kind: "BEGIN_PUT",
     transactionId,
     scope,
@@ -268,6 +270,7 @@ describe("OPFS dedicated worker runtime", () => {
     await Promise.resolve();
     const aborted = await runtime.handleRequest({
       requestId: "request_abort_1234",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
       kind: "ABORT_PUT",
       scope: scopeA,
       transactionId: "transaction_12345678",
@@ -319,6 +322,7 @@ describe("OPFS dedicated worker runtime", () => {
 
     const appending = runtime.handleRequest({
       requestId: "request_append_5678",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
       kind: "APPEND_CHUNK",
       scope: scopeA,
       transactionId: "transaction_56785678",
@@ -328,6 +332,7 @@ describe("OPFS dedicated worker runtime", () => {
     await Promise.resolve();
     const aborting = runtime.handleRequest({
       requestId: "request_abort_5678",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
       kind: "ABORT_PUT",
       scope: scopeA,
       transactionId: "transaction_56785678",
@@ -374,6 +379,7 @@ describe("OPFS dedicated worker runtime", () => {
       expect(
         await runtime.handleRequest({
           requestId: `request_append_iso_${index}`,
+          protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
           kind: "APPEND_CHUNK",
           scope: targetScope,
           transactionId,
@@ -386,6 +392,7 @@ describe("OPFS dedicated worker runtime", () => {
     expect(
       await runtime.handleRequest({
         requestId: "request_abort_iso_a",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "ABORT_PUT",
         scope: scopeA,
         transactionId,
@@ -393,6 +400,7 @@ describe("OPFS dedicated worker runtime", () => {
     ).toMatchObject({ ok: true });
     const finished = await runtime.handleRequest({
       requestId: "request_finish_iso_b",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
       kind: "FINISH_PUT",
       scope: scopeB,
       transactionId,
@@ -402,11 +410,14 @@ describe("OPFS dedicated worker runtime", () => {
     expect(
       await runtime.handleRequest({
         requestId: "request_verify_iso_b",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "VERIFY_OBJECT",
         preparedObject,
       }),
     ).toEqual({
       requestId: "request_verify_iso_b",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+      kind: expect.any(String),
       ok: true,
       value: true,
     });
@@ -435,6 +446,7 @@ describe("OPFS dedicated worker runtime", () => {
       );
       await runtime.handleRequest({
         requestId: `request_gc_append_${index}`,
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "APPEND_CHUNK",
         scope: targetScope,
         transactionId,
@@ -444,6 +456,7 @@ describe("OPFS dedicated worker runtime", () => {
       const object = preparedValue(
         await runtime.handleRequest({
           requestId: `request_gc_finish_${index}`,
+          protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
           kind: "FINISH_PUT",
           scope: targetScope,
           transactionId,
@@ -452,6 +465,7 @@ describe("OPFS dedicated worker runtime", () => {
       preparedByScope.set(targetScope.authorityToken, object);
       await runtime.handleRequest({
         requestId: `request_gc_finalize_${index}`,
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "FINALIZE_PUT",
         transactionId,
         preparedObject: object,
@@ -464,6 +478,7 @@ describe("OPFS dedicated worker runtime", () => {
     expect(
       await runtime.handleRequest({
         requestId: "request_gc_list_a",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "LIST_ORPHAN_CANDIDATES",
         scope: scopeA,
         olderThanEpochMs: cutoff,
@@ -473,6 +488,7 @@ describe("OPFS dedicated worker runtime", () => {
     expect(
       await runtime.handleRequest({
         requestId: "request_gc_delete_a",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "DELETE_ORPHAN_CHUNK",
         scope: scopeA,
         digestHex,
@@ -483,22 +499,28 @@ describe("OPFS dedicated worker runtime", () => {
     expect(
       await runtime.handleRequest({
         requestId: "request_gc_verify_a",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "VERIFY_OBJECT",
         preparedObject: preparedByScope.get(scopeA.authorityToken)!,
       }),
     ).toEqual({
       requestId: "request_gc_verify_a",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+      kind: expect.any(String),
       ok: true,
       value: false,
     });
     expect(
       await runtime.handleRequest({
         requestId: "request_gc_verify_b",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "VERIFY_OBJECT",
         preparedObject: preparedByScope.get(scopeB.authorityToken)!,
       }),
     ).toEqual({
       requestId: "request_gc_verify_b",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+      kind: expect.any(String),
       ok: true,
       value: true,
     });
@@ -516,10 +538,13 @@ describe("OPFS dedicated worker runtime", () => {
     expect(
       await runtime.handleRequest({
         requestId: "request_caps_1234",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
         kind: "CAPABILITIES",
       }),
     ).toEqual({
       requestId: "request_caps_1234",
+      protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+      kind: expect.any(String),
       ok: true,
       value: {
         available: false,
@@ -569,6 +594,8 @@ describe("OPFS worker client lifecycle", () => {
     listener?.({
       data: {
         requestId: "request_collision_1234",
+        protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+        kind: "CAPABILITIES",
         ok: true,
         value: {
           available: true,
@@ -633,11 +660,15 @@ describe("OPFS worker client lifecycle", () => {
           message.kind === "VERIFY_OBJECT"
             ? {
                 requestId: message.requestId,
+                protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+                kind: message.kind,
                 ok: true,
                 value: true,
               }
             : {
                 requestId: message.requestId,
+                protocolVersion: OPFS_WORKER_PROTOCOL_VERSION,
+                kind: message.kind,
                 ok: true,
                 value: new Uint8Array([4, 2]).buffer,
               };