feat(codex): require Codex 0.156 and regenerate its protocol

apps/server/src/provider/Layers/CodexAdapter.test.ts

@@ -2383,6 +2383,7 @@ lifecycleLayer("CodexAdapterLive lifecycle", (it) => {
           method: "item/tool/requestUserInput",
           requestId: ApprovalRequestId.make("req-user-input-1"),
           payload: {
+            isBlocking: true,
             itemId: "item-user-input-1",
             threadId: "thread-1",
             turnId: "turn-1",

apps/server/src/provider/Layers/CodexProvider.ts

@@ -441,7 +441,7 @@ const probeCodexAppServerProvider = Effect.fn("probeCodexAppServerProvider")(fun
       requestAllCodexModels(client),
       // Usage is an enrichment: a failure or a slow answer degrades to "no
       // usage this probe" rather than costing the account and models.
-      client.request("account/rateLimits/read", undefined).pipe(
+      client.request("account/rateLimits/read", null).pipe(
         Effect.map((response): CodexRateLimitsProbe => ({
           snapshot: response.rateLimits,
           rateLimitsByLimitId: response.rateLimitsByLimitId,

apps/server/src/provider/Layers/CodexSessionRuntime.test.ts

@@ -90,25 +90,28 @@ describe("Codex thread history", () => {
     );
   }
 
-  it.effect("keeps the count-based rollback API for older threads", () =>
+  it.effect("surfaces Codex rejecting a revert of a legacy thread", () =>
     Effect.gen(function* () {
+      const rejection = CodexErrors.CodexAppServerRequestError.invalidRequest(
+        "thread/revert only supports paginated threads",
+      );
       const client: Parameters<typeof rollbackCodexThread>[0] = {
-        raw: { request: () => Effect.succeed({ thread: {} }) },
-        request: <M extends CodexRpc.ClientRequestMethod>(
-          method: M,
-          params: CodexRpc.ClientRequestParamsByMethod[M],
-        ) => {
-          NodeAssert.equal(method, "thread/rollback");
-          NodeAssert.deepEqual(params, { threadId: "legacy-thread", numTurns: 2 });
+        raw: {
+          request: (method) => {
+            if (method === "thread/read") return Effect.succeed({ thread: {} });
+            if (method === "thread/revert") return Effect.fail(rejection);
+            return Effect.die(`Unexpected raw request: ${method}`);
+          },
+        },
+        request: <M extends CodexRpc.ClientRequestMethod>(method: M) => {
+          NodeAssert.equal(method, "thread/read");
           return Effect.succeed({
-            thread: { id: "legacy-thread", turns: [] },
+            thread: { id: "legacy-thread", turns: [{ id: "turn-1", items: [] }] },
           } as unknown as CodexRpc.ClientRequestResponsesByMethod[M]);
         },
       };
-      NodeAssert.deepEqual(yield* rollbackCodexThread(client, "legacy-thread", 2), {
-        threadId: "legacy-thread",
-        turns: [],
-      });
+      const error = yield* Effect.flip(rollbackCodexThread(client, "legacy-thread", 1));
+      NodeAssert.strictEqual(error, rejection);
     }),
   );
 });
@@ -680,6 +683,7 @@ function makeThreadStartedNotification(
         id: threadId,
         modelProvider: "openai",
         preview: "",
+        projectId: null,
         sessionId: threadId,
         source,
         status: { type: "idle" as const },

apps/server/src/provider/Layers/CodexSessionRuntime.ts

@@ -163,8 +163,7 @@ export type CodexTurnStartParamsWithCollaborationMode =
 export type CodexResumeCursor = typeof CodexResumeCursorSchema.Type;
 type CodexServiceTier = NonNullable<EffectCodexSchema.V2ThreadStartParams["serviceTier"]>;
 type CodexThreadItem =
-  | EffectCodexSchema.V2ThreadReadResponse["thread"]["turns"][number]["items"][number]
-  | EffectCodexSchema.V2ThreadRollbackResponse["thread"]["turns"][number]["items"][number];
+  EffectCodexSchema.V2ThreadReadResponse["thread"]["turns"][number]["items"][number];
 
 export interface CodexSessionRuntimeOptions {
   readonly threadId: ThreadId;
@@ -1185,7 +1184,7 @@ function updateSession(
 }
 
 function parseThreadSnapshot(
-  response: EffectCodexSchema.V2ThreadReadResponse | EffectCodexSchema.V2ThreadRollbackResponse,
+  response: EffectCodexSchema.V2ThreadReadResponse,
 ): CodexThreadSnapshot {
   return {
     threadId: response.thread.id,
@@ -1273,11 +1272,8 @@ export const rollbackCodexThread = Effect.fn("rollbackCodexThread")(function* (
   threadId: string,
   numTurns: number,
 ): Effect.fn.Return<CodexThreadSnapshot, CodexErrors.CodexAppServerError> {
-  if ((yield* readCodexHistoryMode(client, threadId)) !== "paginated") {
-    return parseThreadSnapshot(yield* client.request("thread/rollback", { threadId, numTurns }));
-  }
-  // Paginated threads replace history at a turn boundary instead of supporting
-  // the legacy count-based rollback endpoint.
+  // Codex replaces history at a turn boundary. It rejects threads that still
+  // use legacy history, which have no rollback API since Codex 0.156.
   const snapshot = yield* readCodexThread(client, threadId);
   const retainedCount = Math.max(0, snapshot.turns.length - numTurns);
   const firstRemoved = snapshot.turns[retainedCount];

apps/server/src/provider/model-manifest.json

@@ -1,14 +1,14 @@
 {
   "version": 1,
-  "updatedAt": "2026-09-24T00:11:29Z",
+  "updatedAt": "2026-09-24T18:40:00Z",
   "compatibility": [
     {
       "driver": "codex",
       "t3CodeRange": ">=0.0.42",
-      "recommendedRange": ">=0.129.0",
+      "recommendedRange": ">=0.156.0",
       "ranges": [
-        { "range": ">=0.129.0", "status": "supported" },
-        { "range": "<0.129.0", "status": "broken" }
+        { "range": ">=0.156.0", "status": "supported" },
+        { "range": "<0.156.0", "status": "unsupported" }
       ]
     },
     {

apps/server/src/provider/providerCompatibility.test.ts

@@ -65,6 +65,22 @@ describe("provider compatibility", () => {
     }
   });
 
+  it("requires Codex 0.156 for every T3 Code build that reads the policy", () => {
+    const bundled = ModelManifest.BUNDLED_MODEL_MANIFEST.compatibility;
+    for (const [t3CodeVersion, codexVersion, expected] of [
+      ["0.0.42", "0.155.0", "unsupported"],
+      ["0.0.42", "0.156.0", "supported"],
+      ["0.0.43-nightly.20260924.2200", "0.153.3", "unsupported"],
+      ["0.0.43-nightly.20260924.2200", "0.156.1", "supported"],
+    ] as const) {
+      assert.strictEqual(
+        resolveProviderCompatibility(bundled, driver, codexVersion, t3CodeVersion)?.status,
+        expected,
+        `T3 Code ${t3CodeVersion} with Codex ${codexVersion}`,
+      );
+    }
+  });
+
   it("compares Cursor build dates without treating semver prereleases as stable", () => {
     const cursor = ProviderDriverKind.make("cursor");
     const cursorPolicy: ProviderCompatibilityPolicy = {

apps/server/src/provider/testFixtures/codexMultiAgentWire.json

@@ -20,6 +20,7 @@
           "forkedFromId": null,
           "parentThreadId": null,
           "preview": "",
+          "projectId": null,
           "ephemeral": false,
           "historyMode": "legacy",
           "modelProvider": "openai",
@@ -389,6 +390,7 @@
         "forkedFromId": null,
         "parentThreadId": null,
         "preview": "",
+        "projectId": null,
         "ephemeral": false,
         "historyMode": "legacy",
         "modelProvider": "openai",

packages/effect-codex-app-server/scripts/generate.ts

@@ -17,7 +17,7 @@ import {
 } from "effect/unstable/http";
 import { ChildProcess, ChildProcessSpawner } from "effect/unstable/process";
 
-const UPSTREAM_REF = "678157acaa819d5510adfe359abb5d0392cfe461";
+const UPSTREAM_REF = "fe74a774532af67b5a4a3dec03ce9469e17f89af";
 const USER_AGENT = "effect-codex-app-server-generator";
 const GITHUB_API_BASE =
   "https://api.github.com/repos/openai/codex/contents/codex-rs/app-server-protocol";
@@ -145,112 +145,6 @@ const ManualSchemas: Record<string, Schema.Json> = {
   },
 };
 
-// Codex 0.150 added these multi-agent values before our next full protocol
-// refresh. Keep every generated response namespace compatible with them.
-const Codex0150DefinitionSchemas: Record<string, Schema.Json> = {
-  CollabAgentTool: {
-    type: "string",
-    enum: [
-      "spawnAgent",
-      "sendInput",
-      "resumeAgent",
-      "wait",
-      "closeAgent",
-      "sendMessage",
-      "followupTask",
-      "interruptAgent",
-      "listAgents",
-    ],
-  },
-  CollabAgentToolCallStatus: {
-    type: "string",
-    enum: ["inProgress", "completed", "failed", "interrupted"],
-  },
-  PlanType: {
-    type: "string",
-    enum: [
-      "free",
-      "go",
-      "plus",
-      "pro",
-      "prolite",
-      "team",
-      "self_serve_business_prolite",
-      "self_serve_business_usage_based",
-      "business",
-      "ent26",
-      "enterprise_cbp_automation",
-      "enterprise_cbp_usage_based",
-      "enterprise",
-      "edu",
-      "edu_plus",
-      "edu_pro",
-      "unknown",
-    ],
-  },
-  SubAgentActivityKind: {
-    type: "string",
-    enum: ["started", "interacted", "interrupted", "completed"],
-  },
-};
-
-// Pinned protocol JSON omits later CodexErrorInfo variants. Keep historical
-// thread payloads decodable; do not fold unknown values into "other".
-const CodexErrorInfoCompatibilityValues = [
-  "rateLimitExceeded",
-  "misalignmentPolicyViolation",
-] as const;
-
-const CodexErrorInfoCompatibilityExports = new Set([
-  "V2ThreadReadResponse",
-  "V2ThreadResumeResponse",
-  "V2ThreadRollbackResponse",
-  "V2ThreadForkResponse",
-  "V2TurnCompletedNotification",
-]);
-
-function applyCodex0151DefinitionCompatibility(
-  exportName: string,
-  definitionName: string,
-  definitionSchema: Schema.Json,
-): Schema.Json {
-  if (
-    !CodexErrorInfoCompatibilityExports.has(exportName) ||
-    definitionName !== "CodexErrorInfo" ||
-    typeof definitionSchema !== "object"
-  ) {
-    return definitionSchema;
-  }
-
-  const schema = definitionSchema as {
-    readonly oneOf?: ReadonlyArray<{ readonly enum?: ReadonlyArray<string> }>;
-  };
-  const [firstVariant, ...remainingVariants] = schema.oneOf ?? [];
-  const currentEnum = firstVariant?.enum;
-  if (!currentEnum) {
-    return definitionSchema;
-  }
-
-  const missingValues = CodexErrorInfoCompatibilityValues.filter(
-    (value) => !currentEnum.includes(value),
-  );
-  if (missingValues.length === 0) {
-    return definitionSchema;
-  }
-
-  const enumValues = [...currentEnum];
-  const otherIndex = enumValues.indexOf("other");
-  const nextEnum =
-    otherIndex === -1
-      ? [...enumValues, ...missingValues]
-      : [...enumValues.slice(0, otherIndex), ...missingValues, ...enumValues.slice(otherIndex)];
-
-  return {
-    ...definitionSchema,
-    oneOf: [{ ...firstVariant, enum: nextEnum }, ...remainingVariants],
-  };
-}
-
 const getGeneratedPaths = Effect.fn("getGeneratedPaths")(function* () {
   const path = yield* Path.Path;
   const generatedDir = path.join(import.meta.dirname, "..", "src", "_generated");
@@ -470,61 +364,6 @@ function adaptSchemaForEffect(value: Schema.Json): Schema.Json {
   };
 }
 
-// Codex 0.153 adds async questions to agent messages. Keep older protocol
-// fields until the next full refresh, including every thread history namespace.
-function addAsyncQuestionFields(value: Schema.Json): Schema.Json {
-  if (Array.isArray(value)) {
-    return value.map(addAsyncQuestionFields);
-  }
-  if (value === null || typeof value !== "object") {
-    return value;
-  }
-  const properties = "properties" in value ? value.properties : undefined;
-  const itemType =
-    properties && typeof properties === "object" && "type" in properties
-      ? properties.type
-      : undefined;
-  if (
-    properties &&
-    typeof properties === "object" &&
-    itemType &&
-    typeof itemType === "object" &&
-    "enum" in itemType &&
-    Array.isArray(itemType.enum) &&
-    itemType.enum.includes("agentMessage")
-  ) {
-    return {
-      ...value,
-      properties: {
-        ...Object.fromEntries(Object.entries(properties).filter(([key]) => key !== "type")),
-        delivery: { anyOf: [{ type: "string", enum: ["async"] }, { type: "null" }] },
-        questions: {
-          anyOf: [
-            {
-              type: "array",
-              items: {
-                type: "object",
-                properties: {
-                  title: { type: "string" },
-                  options: {
-                    anyOf: [{ type: "array", items: { type: "string" } }, { type: "null" }],
-                  },
-                },
-                required: ["title"],
-              },
-            },
-            { type: "null" },
-          ],
-        },
-        type: itemType,
-      },
-    };
-  }
-  return Object.fromEntries(
-    Object.entries(value).map(([key, child]) => [key, addAsyncQuestionFields(child)]),
-  );
-}
-
 function toPascalCaseMethod(method: string) {
   return method
     .split("/")
@@ -536,13 +375,14 @@ function toPascalCaseMethod(method: string) {
 }
 
 function parseRequestEntries(fileContents: string): ReadonlyArray<MethodEntry> {
-  const entryPattern = /\{\s*"method":\s*"([^"]+)",\s*id:\s*RequestId,\s*params:\s*([^,}]+)/g;
+  // Optional params render as `params?: Foo | undefined`; their JSON schema is `NullableFoo`.
+  const entryPattern = /\{\s*"method":\s*"([^"]+)",\s*id:\s*RequestId,\s*params(\??):\s*([^,}|]+)/g;
   const entries: Array<MethodEntry> = [];
   let match: RegExpExecArray | null;
   while ((match = entryPattern.exec(fileContents)) !== null) {
     entries.push({
       method: match[1]!,
-      paramsType: match[2]!.trim(),
+      paramsType: `${match[2] ? "Nullable" : ""}${match[3]!.trim()}`,
     });
   }
   return entries;
@@ -800,13 +640,10 @@ const generateFiles = Effect.fn("generateFiles")(function* () {
     );
 
     for (const [definitionName, definitionSchema] of Object.entries(parsed.definitions ?? {})) {
-      const compatibleDefinitionSchema =
-        Codex0150DefinitionSchemas[definitionName] ??
-        applyCodex0151DefinitionCompatibility(file.exportName, definitionName, definitionSchema);
       aggregateSchemas[localDefinitionNames.get(definitionName)!] = stripNullDefaults(
         normalizeNullableTypes(
           rewriteExternalRefs(
-            compatibleDefinitionSchema,
+            definitionSchema,
             localDefinitionNames,
             file.namespace,
             exportNameByQualifiedName,
@@ -844,7 +681,7 @@ const generateFiles = Effect.fn("generateFiles")(function* () {
   for (const [name, schema] of Object.entries(aggregateSchemas).toSorted(([left], [right]) =>
     left.localeCompare(right),
   )) {
-    aggregateSchemas[name] = adaptSchemaForEffect(addAsyncQuestionFields(schema));
+    aggregateSchemas[name] = adaptSchemaForEffect(schema);
     generator.addSchema(name, aggregateSchemas[name] as never);
   }