feat: send chatgpt-account-id from the source's quirks

AGENTS.md

@@ -12,7 +12,7 @@ than reimplementing OAuth or the Responses wire protocol.
 - `src/constants.ts` — endpoints, client id, headers, timeouts.
 - `src/oauth.ts` — `codexOAuthConfig`, `accountIdFromIdToken`, token-response mapping.
 - `src/instructions.ts` — the bridge-message wrap for the host's operating prompt.
-- `src/quirks.ts` — `CodexQuirks`, the host-identity bag `wrapCodexBridgeMessage` needs.
+- `src/quirks.ts` — `CodexQuirks`, the host-identity bag `wrapCodexBridgeMessage` needs, plus the optional `chatgpt-account-id`.
 - `src/responses-adapter.ts` — `createCodexResponsesAdapter`, a plain `(source, quirks?)` `AdapterFactory`.
 - `src/content-type-repair.ts` — `withCodexContentTypeRepair`, a fetch decorator for a backend content-type bug.
 - `src/index.ts` — the public surface; nothing else is imported by consumers.

README.md

@@ -100,7 +100,7 @@ process.stdout.write("\n");
 | `codexTokensFromResponse(response, now, previousRefresh?)` | Maps a token endpoint response to `CodexTokens`.                                                                     |
 | `accountIdFromIdToken(idToken)`                            | Reads the ChatGPT account id from an `id_token`. Returns `undefined` on malformed input; does not verify signatures. |
 | `wrapCodexBridgeMessage(prompt, identity)`                 | The leading `developer` message the adapter builds from the host's system prompt.                                    |
-| `CodexQuirks`, `parseCodexQuirks`, `CodexQuirksError`      | Schema, parser and error for `{ productName, environmentTagName }`. Unknown keys are rejected.                       |
+| `CodexQuirks`, `parseCodexQuirks`, `CodexQuirksError`      | Schema, parser and error for `{ productName, environmentTagName, accountId? }`. Unknown keys are rejected.           |
 | `CodexTokens`, `FetchLike`                                 | Types.                                                                                                               |
 | `CODEX_PROVIDER`                                           | The `"codex"` provider id.                                                                                           |
 | `CODEX_BASE_URL`, `CODEX_RESPONSES_PATH`                   | `https://chatgpt.com/backend-api` and `/codex/responses`.                                                            |
@@ -159,7 +159,7 @@ export const deps = {
 };
 ```
 
-Each Codex source points at `CODEX_BASE_URL`, uses the OAuth access token as its credential, and carries `quirks: { productName, environmentTagName }` naming the host. Pass the credential's `accountId` metadata as `providerOptions[CODEX_ACCOUNT_ID_OPTION]`.
+Each Codex source points at `CODEX_BASE_URL`, uses the OAuth access token as its credential, and carries `quirks: { productName, environmentTagName }` naming the host. Put the credential's `accountId` metadata in the source's quirks as `accountId`; it is sent as `chatgpt-account-id`, and a per-call `providerOptions[CODEX_ACCOUNT_ID_OPTION]` overrides it. The quirk binds the source to one ChatGPT account, so each account's credential needs its own source, and the quirk is re-set when the credential is signed in to another account.
 
 ## License
 

src/quirks.ts

@@ -3,15 +3,22 @@ import { type, type Type } from "arktype";
 interface CodexQuirksShape {
   productName: string;
   environmentTagName: string;
+  accountId?: string;
 }
 
 /**
- * Host identity a Codex bridge message needs and cannot default. An absent
- * bag is a validation error — there is no honest generic product name.
+ * Host identity a Codex bridge message needs and cannot default, plus the
+ * optional ChatGPT account the requests are sent for. An absent bag is a
+ * validation error — there is no honest generic product name.
  */
 export const CodexQuirks: Type<CodexQuirksShape> = type({
   productName: "string",
   environmentTagName: "string",
+  // Sent as `chatgpt-account-id` on every request. A catalog source carries
+  // no providerOptions, so a deployment states the account here. Visible
+  // ASCII only, so a value that is not a valid header fails here rather than
+  // on every request.
+  "accountId?": /^[\x21-\x7e]+$/,
   "+": "reject",
 });
 export type CodexQuirks = CodexQuirksShape;

src/responses-adapter.test.ts

@@ -1,7 +1,7 @@
 import type { ConversationTurn, LastCycleSource } from "@intx/types/runtime";
 import { type } from "arktype";
 import { describe, expect, test } from "bun:test";
-import { createCodexResponsesAdapter } from "./index.js";
+import { CodexQuirksError, createCodexResponsesAdapter } from "./index.js";
 
 const source: LastCycleSource = {
   sourceId: "test/codex",
@@ -57,6 +57,27 @@ describe("Codex responses adapter — request shape", () => {
     expect(withoutAccount.headers["chatgpt-account-id"]).toBeUndefined();
   });
 
+  test("sends the account id quirk as the header, and the option overrides it", () => {
+    const adapter = createCodexResponsesAdapter(source, {
+      ...quirks,
+      accountId: "acct-quirk",
+    });
+    expect(
+      adapter.buildRequest(turns, "gpt-5.5", {}).headers["chatgpt-account-id"],
+    ).toBe("acct-quirk");
+    expect(
+      adapter.buildRequest(turns, "gpt-5.5", {
+        providerOptions: { codexAccountId: "acct-option" },
+      }).headers["chatgpt-account-id"],
+    ).toBe("acct-option");
+  });
+
+  test("rejects an account id quirk that would split the header", () => {
+    expect(() =>
+      createCodexResponsesAdapter(source, { ...quirks, accountId: "a\r\nb" }),
+    ).toThrow(CodexQuirksError);
+  });
+
   test("sends the session id in both the body and the header", () => {
     const adapter = createCodexResponsesAdapter(source, quirks);
     const request = adapter.buildRequest(turns, "gpt-5.5", {

src/responses-adapter.ts

@@ -16,13 +16,16 @@ import { parseCodexQuirks, type CodexQuirks } from "./quirks.js";
 
 // `store` and `parallelToolCalls` need an explicit `false` on the wire, and
 // `maxOutputTokens: false` because the backend 400s on `max_output_tokens`.
-function codexResponsesQuirks(): ResponsesQuirks {
+function codexResponsesQuirks(quirks: CodexQuirks): ResponsesQuirks {
   return {
     path: CODEX_RESPONSES_PATH,
     headers: {
       static: {
         "openai-beta": "responses=experimental",
         originator: CODEX_ORIGINATOR,
+        ...(quirks.accountId !== undefined
+          ? { "chatgpt-account-id": quirks.accountId }
+          : {}),
       },
       fromOption: [
         { optionKey: CODEX_ACCOUNT_ID_OPTION, header: "chatgpt-account-id" },
@@ -55,7 +58,8 @@ function codexResponsesHooks(quirks: CodexQuirks): ResponsesHooks {
 /**
  * `AdapterFactory` for Codex's Responses-speaking ChatGPT backend. `quirks`
  * is this package's own {@link CodexQuirks} (an `InferenceSource.quirks`
- * bag) carrying the host identity `wrapCodexBridgeMessage` needs; unlike
+ * bag) carrying the host identity `wrapCodexBridgeMessage` needs and the
+ * optional `chatgpt-account-id`; unlike
  * `@corbits/openai-responses`'s own quirks, an absent bag is a validation
  * error rather than a default, since there is no honest generic product
  * name to fall back to. This shape — `(source, quirks?)` — is what makes
@@ -64,7 +68,7 @@ function codexResponsesHooks(quirks: CodexQuirks): ResponsesHooks {
 export const createCodexResponsesAdapter: AdapterFactory = (source, quirks) => {
   const parsed = parseCodexQuirks(quirks);
   return responsesAdapterFactory(
-    codexResponsesQuirks(),
+    codexResponsesQuirks(parsed),
     codexResponsesHooks(parsed),
   )(source);
 };