diff --git a/open-sse/executors/chatgpt-session.ts b/open-sse/executors/chatgpt-session.ts
new file mode 100644
index 0000000000..4633406c0f
--- /dev/null
+++ b/open-sse/executors/chatgpt-session.ts
@@ -0,0 +1,333 @@
+/**
+ * ChatGptSessionExecutor — OpenAI chat completions over an authenticated ChatGPT browser
+ * session.
+ *
+ * The vendored MIT browser adapter owns every anti-bot interaction (sentinel, turnstile,
+ * proof-of-work) because a real signed-in browser performs them; this executor only translates
+ * request and response shapes around it.
+ */
+
+import { CHATGPT_WEB_CODEX_CONNECTOR_NAME } from "@/shared/constants/chatgptWebCodex";
+
+import { FORMATS } from "../translator/formats.ts";
+import { prepareToolMessages } from "../translator/webTools.ts";
+import { buildErrorBody, sanitizeErrorMessage } from "../utils/error.ts";
+import { AsyncEventQueue } from "../vendor/codex-chatgpt-web/event-queue.ts";
+import type { AdapterEvent, CodexProviderConfig } from "../vendor/codex-chatgpt-web/types.ts";
+import { BaseExecutor, type ExecuteInput, type ExecutorExecuteResult } from "./base.ts";
+import { buildToolModeResponse } from "./chatgptWebTools.ts";
+import {
+  decodeChatGptWebCodexSecrets,
+  encodeChatGptWebCodexSecrets,
+} from "./chatgpt-web-codex/credentials.ts";
+import { connectionRuntimePaths } from "./chatgpt-web-codex/storageState.ts";
+import {
+  buildChatGptSessionCompletion,
+  openChatGptSessionStream,
+  type ChatGptSessionResponseMeta,
+} from "./chatgpt-session/bridge.ts";
+import { classifyChatGptSessionError } from "./chatgpt-session/errors.ts";
+import { buildParsedRequest } from "./chatgpt-session/messages.ts";
+import { requireChatGptSessionRoute, type ChatGptSessionRoute } from "./chatgpt-session/models.ts";
+import {
+  chatGptSessionRuntime,
+  type ChatGptSessionLoginConfig,
+} from "./chatgpt-session/runtime.ts";
+
+const BASE_URL = "https://chatgpt.com";
+const JSON_HEADERS = { "Content-Type": "application/json" };
+const SSE_HEADERS = {
+  "Cache-Control": "no-cache, no-transform",
+  Connection: "keep-alive",
+  "Content-Type": "text/event-stream; charset=utf-8",
+};
+
+function record(value: unknown): Record<string, unknown> {
+  return value && typeof value === "object" && !Array.isArray(value)
+    ? (value as Record<string, unknown>)
+    : {};
+}
+
+function configuredString(data: Record<string, unknown>, ...keys: string[]): string | undefined {
+  for (const key of keys) {
+    const value = data[key];
+    if (typeof value === "string" && value.trim()) return value.trim();
+  }
+  return undefined;
+}
+
+function wrapped(response: Response, body: unknown): ExecutorExecuteResult {
+  return {
+    response,
+    url: BASE_URL,
+    headers: {},
+    transformedBody: body,
+    transport: "chatgpt-session-browser",
+  };
+}
+
+function errorResponse(
+  status: number,
+  message: unknown,
+  code: string,
+  fallbackHint?: "connection_cooldown"
+): Response {
+  return new Response(
+    JSON.stringify(
+      buildErrorBody(status, sanitizeErrorMessage(message), undefined, {
+        type: status >= 500 ? "provider_error" : "invalid_request_error",
+        code,
+      })
+    ),
+    {
+      status,
+      headers: fallbackHint
+        ? { ...JSON_HEADERS, "X-Omni-Fallback-Hint": fallbackHint }
+        : JSON_HEADERS,
+    }
+  );
+}
+
+export function buildChatGptSessionProviderConfig(args: {
+  route: ChatGptSessionRoute;
+  connectionId: string;
+  storageStatePath: string;
+  connectorName: string;
+  chromeExecutablePath?: string;
+  cdpEndpoint?: string;
+  solAvailable: boolean;
+  proAvailable: boolean;
+}): CodexProviderConfig {
+  const paths = connectionRuntimePaths(args.connectionId);
+  return {
+    adapter: "chatgpt-web",
+    baseUrl: BASE_URL,
+    defaultModel: args.route.backendModel,
+    models: [args.route.backendModel],
+    chatgptWeb: {
+      appName: args.connectorName,
+      storageStatePath: args.storageStatePath,
+      ...(args.chromeExecutablePath ? { chromeExecutablePath: args.chromeExecutablePath } : {}),
+      ...(args.cdpEndpoint ? { cdpEndpoint: args.cdpEndpoint } : {}),
+      brokerSocketPath: paths.brokerSocketPath,
+      threadEnvironmentStatePath: paths.threadEnvironmentStatePath,
+      lunaCheckpointStatePath: paths.lunaCheckpointStatePath,
+      headed: true,
+      // Prompt-emulated tools only: never attach the turn-bound Codex connector capability.
+      localToolsEnabled: false,
+      solAvailable: args.solAvailable,
+      proAvailable: args.proAvailable,
+      autoApproveToolCalls: false,
+    },
+  };
+}
+
+export class ChatGptSessionExecutor extends BaseExecutor {
+  constructor() {
+    super("chatgpt-session", {
+      id: "chatgpt-session",
+      baseUrl: BASE_URL,
+      format: FORMATS.OPENAI,
+    });
+  }
+
+  override async execute(input: ExecuteInput): Promise<ExecutorExecuteResult> {
+    const runtime = chatGptSessionRuntime();
+    const requestBody = record(input.body);
+
+    try {
+      const route = requireChatGptSessionRoute(input.model);
+
+      const connectionId = input.credentials.connectionId?.trim();
+      const encodedCredentials = input.credentials.apiKey?.trim();
+      if (!connectionId || !encodedCredentials) {
+        throw new Error("ChatGPT browser credentials are missing");
+      }
+      const secrets = decodeChatGptWebCodexSecrets(encodedCredentials);
+
+      const providerData = record(input.credentials.providerSpecificData);
+      const cdpEndpoint =
+        configuredString(providerData, "browserCdpEndpoint") ??
+        process.env.CHATGPT_WEB_CODEX_CDP_URL?.trim();
+      const chromeExecutablePath = runtime.detectChrome(
+        configuredString(providerData, "chromeExecutablePath")
+      );
+      if (!chromeExecutablePath && !cdpEndpoint) {
+        throw new Error("No supported Chrome or Chromium executable was found");
+      }
+
+      const storageStatePath = runtime.ensureStorageState(connectionId, secrets);
+      const connectorName =
+        configuredString(providerData, "connectorName", "appName") ??
+        CHATGPT_WEB_CODEX_CONNECTOR_NAME;
+
+      const loginConfig: ChatGptSessionLoginConfig = {
+        appName: connectorName,
+        storageStatePath,
+        headed: true,
+        proAvailable: providerData.proAvailable === true,
+        autoApproveToolCalls: false,
+        ...(chromeExecutablePath ? { chromeExecutablePath } : {}),
+        ...(cdpEndpoint ? { cdpEndpoint } : {}),
+      };
+
+      let solAvailable = providerData.solAvailable !== false;
+      let proAvailable = providerData.proAvailable === true;
+      if (!runtime.loginStateExists(loginConfig)) {
+        const capabilities = await runtime.inspectLogin(loginConfig);
+        solAvailable = capabilities.solAvailable;
+        proAvailable = capabilities.proAvailable;
+        await input.onCredentialsRefreshed?.({
+          providerSpecificData: {
+            ...providerData,
+            solAvailable,
+            proAvailable,
+            browserVerified: true,
+            ...(chromeExecutablePath ? { chromeExecutablePath } : {}),
+            ...(cdpEndpoint ? { browserCdpEndpoint: cdpEndpoint } : {}),
+          },
+        });
+      }
+
+      if (route.sol !== solAvailable) {
+        throw new Error(
+          route.sol
+            ? `${route.id} is not available for this Luna-only connection`
+            : `${route.id} is not available while the account exposes the Sol model selector`
+        );
+      }
+      if (route.pro && !proAvailable) {
+        throw new Error(`${route.id} is not available for this non-Pro connection`);
+      }
+
+      const messages = Array.isArray(requestBody.messages)
+        ? (requestBody.messages as Array<{ role: string; content: unknown }>)
+        : [];
+      const { hasTools, requestedTools, effectiveMessages } = prepareToolMessages(
+        requestBody,
+        messages
+      );
+
+      const parsed = buildParsedRequest({
+        route,
+        messages: effectiveMessages,
+        stream: Boolean(input.stream) && !hasTools,
+        rawBody: input.body,
+      });
+
+      const provider = buildChatGptSessionProviderConfig({
+        route,
+        connectionId,
+        storageStatePath,
+        connectorName,
+        solAvailable,
+        proAvailable,
+        ...(chromeExecutablePath ? { chromeExecutablePath } : {}),
+        ...(cdpEndpoint ? { cdpEndpoint } : {}),
+      });
+
+      const events = new AsyncEventQueue<AdapterEvent>();
+      const incoming = {
+        headers: new Headers(),
+        ...(input.signal ? { abortSignal: input.signal } : {}),
+      };
+
+      const persistRotatedState = async () => {
+        try {
+          const storageState = runtime.readStorageState(storageStatePath);
+          await input.onCredentialsRefreshed?.({
+            apiKey: encodeChatGptWebCodexSecrets({
+              storageState,
+              ...(secrets.runtimeKey ? { runtimeKey: secrets.runtimeKey } : {}),
+            }),
+          });
+        } catch (refreshError) {
+          input.log?.warn?.(
+            "CHATGPT_SESSION",
+            sanitizeErrorMessage(
+              refreshError instanceof Error ? refreshError.message : refreshError
+            )
+          );
+        }
+      };
+
+      const run = async () => {
+        try {
+          await runtime.runTurn(parsed, incoming, (event) => events.push(event), provider);
+        } catch (error) {
+          const classified = classifyChatGptSessionError(error);
+          events.push({
+            type: "error",
+            message: sanitizeErrorMessage(error instanceof Error ? error.message : error),
+            status: classified.status,
+            code: classified.code,
+          });
+        } finally {
+          await persistRotatedState();
+          events.close();
+        }
+      };
+
+      const meta: ChatGptSessionResponseMeta = {
+        cid: `chatcmpl-cgpts-${crypto.randomUUID().slice(0, 12)}`,
+        created: Math.floor(Date.now() / 1000),
+        model: input.model,
+      };
+
+      if (!parsed.stream) {
+        const running = run();
+        const collected = await events.collect();
+        await running;
+        const built = buildChatGptSessionCompletion(collected, meta);
+        const jsonResponse = new Response(JSON.stringify(built.body), {
+          status: built.status,
+          headers: JSON_HEADERS,
+        });
+        if (!hasTools || built.status !== 200) return wrapped(jsonResponse, input.body);
+        const toolResponse = await buildToolModeResponse(
+          jsonResponse,
+          requestedTools,
+          Boolean(input.stream),
+          { cid: meta.cid, created: meta.created, model: meta.model, idSeed: "cgpts" }
+        );
+        return wrapped(toolResponse, input.body);
+      }
+
+      void run();
+      const opened = await openChatGptSessionStream(events, meta);
+      if (opened.kind === "error") {
+        // Re-classify from the raw message so a message-derived hint (e.g. the
+        // connection-cooldown hint on a browser failure) is not lost.
+        const classified = classifyChatGptSessionError(new Error(opened.message));
+        return wrapped(
+          errorResponse(
+            classified.status,
+            opened.message,
+            classified.code,
+            classified.fallbackHint
+          ),
+          input.body
+        );
+      }
+      return wrapped(
+        new Response(opened.stream, { status: 200, headers: SSE_HEADERS }),
+        input.body
+      );
+    } catch (error) {
+      const classified = classifyChatGptSessionError(error);
+      input.log?.warn?.(
+        "CHATGPT_SESSION",
+        sanitizeErrorMessage(error instanceof Error ? error.message : error)
+      );
+      return wrapped(
+        errorResponse(
+          classified.status,
+          error instanceof Error ? error.message : error,
+          classified.code,
+          classified.fallbackHint
+        ),
+        input.body
+      );
+    }
+  }
+}
diff --git a/open-sse/executors/chatgpt-session/runtime.ts b/open-sse/executors/chatgpt-session/runtime.ts
new file mode 100644
index 0000000000..fc107d8f39
--- /dev/null
+++ b/open-sse/executors/chatgpt-session/runtime.ts
@@ -0,0 +1,73 @@
+/**
+ * Indirection layer over every side-effecting dependency of the executor (browser detection,
+ * storage-state IO, login probe, adapter turn). Tests swap the whole record so no unit test
+ * ever launches Chrome; production resolves to the vendored implementations.
+ */
+
+import { createChatGptWebAdapter } from "../../vendor/codex-chatgpt-web/adapters/chatgpt-web/index.ts";
+import {
+  browserLoginStateExists,
+  inspectBrowserLoginCapabilities,
+} from "../../vendor/codex-chatgpt-web/browser-login.ts";
+import type {
+  AdapterEvent,
+  CodexParsedRequest,
+  CodexProviderConfig,
+} from "../../vendor/codex-chatgpt-web/types.ts";
+import { detectChromeExecutable } from "../chatgpt-web-codex.ts";
+import {
+  ensureConnectionStorageStateFromCredential,
+  readConnectionStorageState,
+} from "../chatgpt-web-codex/storageState.ts";
+
+export interface ChatGptSessionLoginConfig {
+  appName: string;
+  storageStatePath: string;
+  headed: boolean;
+  proAvailable: boolean;
+  autoApproveToolCalls: boolean;
+  chromeExecutablePath?: string;
+  cdpEndpoint?: string;
+}
+
+export interface ChatGptSessionRuntime {
+  detectChrome(explicit?: string): string | undefined;
+  ensureStorageState(
+    connectionId: string,
+    credential: { cookie?: string; storageState?: Record<string, unknown> }
+  ): string;
+  readStorageState(path: string): Record<string, unknown>;
+  loginStateExists(config: ChatGptSessionLoginConfig): boolean;
+  inspectLogin(
+    config: ChatGptSessionLoginConfig
+  ): Promise<{ solAvailable: boolean; proAvailable: boolean }>;
+  runTurn(
+    parsed: CodexParsedRequest,
+    incoming: { headers: Headers; abortSignal?: AbortSignal },
+    emit: (event: AdapterEvent) => void,
+    provider: CodexProviderConfig
+  ): Promise<void>;
+}
+
+const productionRuntime: ChatGptSessionRuntime = {
+  detectChrome: (explicit) => detectChromeExecutable(explicit),
+  ensureStorageState: (connectionId, credential) =>
+    ensureConnectionStorageStateFromCredential(connectionId, credential),
+  readStorageState: (path) => readConnectionStorageState(path),
+  loginStateExists: (config) => browserLoginStateExists(config),
+  inspectLogin: (config) => inspectBrowserLoginCapabilities(config),
+  runTurn: (parsed, incoming, emit, provider) =>
+    createChatGptWebAdapter(provider).runTurn(parsed, incoming, emit),
+};
+
+let override: Partial<ChatGptSessionRuntime> | null = null;
+
+export function __setChatGptSessionRuntimeForTesting(
+  next: Partial<ChatGptSessionRuntime> | null
+): void {
+  override = next;
+}
+
+export function chatGptSessionRuntime(): ChatGptSessionRuntime {
+  return override ? { ...productionRuntime, ...override } : productionRuntime;
+}
diff --git a/tests/unit/chatgpt-session-executor.test.ts b/tests/unit/chatgpt-session-executor.test.ts
new file mode 100644
index 0000000000..90d9b59cf5
--- /dev/null
+++ b/tests/unit/chatgpt-session-executor.test.ts
@@ -0,0 +1,194 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { ChatGptSessionExecutor } from "../../open-sse/executors/chatgpt-session.ts";
+import { __setChatGptSessionRuntimeForTesting } from "../../open-sse/executors/chatgpt-session/runtime.ts";
+import type { AdapterEvent } from "../../open-sse/vendor/codex-chatgpt-web/types.ts";
+
+const CREDENTIALS = {
+  connectionId: "conn-1",
+  apiKey: JSON.stringify({ version: 2, storageState: { cookies: [], origins: [] } }),
+  providerSpecificData: { solAvailable: true, proAvailable: false, browserVerified: true },
+};
+
+function stubRuntime(events: AdapterEvent[], overrides: Record<string, unknown> = {}) {
+  __setChatGptSessionRuntimeForTesting({
+    detectChrome: () => "/usr/bin/chromium",
+    ensureStorageState: () => "/tmp/state.json",
+    readStorageState: () => ({ cookies: [], origins: [] }),
+    loginStateExists: () => true,
+    inspectLogin: async () => ({ solAvailable: true, proAvailable: false }),
+    runTurn: async (_parsed, _incoming, emit) => {
+      for (const event of events) emit(event);
+    },
+    ...overrides,
+  });
+}
+
+function body(extra: Record<string, unknown> = {}) {
+  return { messages: [{ role: "user", content: "Hi" }], ...extra };
+}
+
+test.afterEach(() => {
+  __setChatGptSessionRuntimeForTesting(null);
+});
+
+test("returns a streaming completion for a normal turn", async () => {
+  stubRuntime([{ type: "text_delta", text: "Hello" }, { type: "done" }]);
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body(),
+    stream: true,
+    credentials: CREDENTIALS,
+  });
+  const response = "response" in result ? result.response : result;
+  assert.equal(response.status, 200);
+  assert.equal(response.headers.get("Content-Type"), "text/event-stream; charset=utf-8");
+  const text = await response.text();
+  assert.match(text, /"content":"Hello"/);
+});
+
+test("returns a buffered completion when stream is false", async () => {
+  stubRuntime([{ type: "text_delta", text: "Hello" }, { type: "done" }]);
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body(),
+    stream: false,
+    credentials: CREDENTIALS,
+  });
+  const response = "response" in result ? result.response : result;
+  const json = (await response.json()) as Record<string, unknown>;
+  assert.equal(json.object, "chat.completion");
+  assert.equal(
+    ((json.choices as Array<Record<string, unknown>>)[0].message as Record<string, unknown>)
+      .content,
+    "Hello"
+  );
+});
+
+test("answers 503 with a cooldown hint when no browser is installed", async () => {
+  stubRuntime([], { detectChrome: () => undefined });
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body(),
+    stream: true,
+    credentials: CREDENTIALS,
+  });
+  const response = "response" in result ? result.response : result;
+  assert.equal(response.status, 503);
+  assert.equal(response.headers.get("X-Omni-Fallback-Hint"), "connection_cooldown");
+});
+
+test("answers 401 when the connection has no credentials", async () => {
+  stubRuntime([]);
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body(),
+    stream: true,
+    credentials: { connectionId: "conn-1" },
+  });
+  const response = "response" in result ? result.response : result;
+  assert.equal(response.status, 401);
+});
+
+test("rejects a Pro route on a non-Pro account without touching the browser", async () => {
+  let ran = false;
+  stubRuntime([], {
+    runTurn: async () => {
+      ran = true;
+    },
+  });
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "pro",
+    body: body(),
+    stream: true,
+    credentials: CREDENTIALS,
+  });
+  const response = "response" in result ? result.response : result;
+  assert.equal(response.status, 400);
+  assert.equal(ran, false);
+});
+
+test("an expired session before output becomes a 401, not a 200 stream", async () => {
+  stubRuntime([{ type: "error", message: "ChatGPT page is not authenticated" }]);
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body(),
+    stream: true,
+    credentials: CREDENTIALS,
+  });
+  const response = "response" in result ? result.response : result;
+  assert.equal(response.status, 401);
+  const json = (await response.json()) as { error: { message: string } };
+  assert.doesNotMatch(json.error.message, /at \//);
+});
+
+test("persists rotated storage state through onCredentialsRefreshed", async () => {
+  stubRuntime([{ type: "text_delta", text: "x" }, { type: "done" }], {
+    readStorageState: () => ({ cookies: [{ name: "rotated" }], origins: [] }),
+  });
+  const patches: Array<Record<string, unknown>> = [];
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body(),
+    stream: false,
+    credentials: CREDENTIALS,
+    onCredentialsRefreshed: async (patch) => {
+      patches.push(patch);
+    },
+  });
+  const response = "response" in result ? result.response : result;
+  await response.text();
+  const persisted = patches.find((patch) => typeof patch.apiKey === "string");
+  assert.ok(persisted, "expected an apiKey patch");
+  assert.match(String(persisted.apiKey), /rotated/);
+});
+
+test("emulated tool calls go through the shared web-tools contract", async () => {
+  stubRuntime([
+    { type: "text_delta", text: '<tool>{"name": "get_time", "arguments": {}}</tool>' },
+    { type: "done" },
+  ]);
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body({
+      tools: [
+        {
+          type: "function",
+          function: { name: "get_time", description: "time", parameters: { type: "object" } },
+        },
+      ],
+    }),
+    stream: false,
+    credentials: CREDENTIALS,
+  });
+  const response = "response" in result ? result.response : result;
+  const json = (await response.json()) as Record<string, unknown>;
+  const choice = (json.choices as Array<Record<string, unknown>>)[0];
+  assert.equal(choice.finish_reason, "tool_calls");
+});
+
+test("forwards the abort signal to the adapter", async () => {
+  let seenSignal: AbortSignal | undefined;
+  stubRuntime([{ type: "done" }], {
+    runTurn: async (
+      _parsed: unknown,
+      incoming: { abortSignal?: AbortSignal },
+      emit: (e: AdapterEvent) => void
+    ) => {
+      seenSignal = incoming.abortSignal;
+      emit({ type: "done" });
+    },
+  });
+  const controller = new AbortController();
+  const result = await new ChatGptSessionExecutor().execute({
+    model: "high",
+    body: body(),
+    stream: false,
+    credentials: CREDENTIALS,
+    signal: controller.signal,
+  });
+  const response = "response" in result ? result.response : result;
+  await response.text();
+  assert.equal(seenSignal, controller.signal);
+});