codex-app-server/cloud/codex-ui-host/host/shim.js

/* Codex web host shim — browser-only replacement for the Electron preload.
 *
 * Loaded as a classic script before the module entry. It provides the two
 * pieces of the Electron shell the renderer cannot live without:
 *
 *   window.electronBridge  — the preload API surface. Only the members the
 *                            renderer actually probes are meaningful; the rest
 *                            resolve to inert promises so .then/.catch chains
 *                            stay valid.
 *   the app-server bridge  — request envelopes sent through
 *                            sendMessageFromView are forwarded to the local
 *                            codex app server and answered on the window
 *                            message bus, which is where the renderer listens.
 */
(() => {
  const noop = () => {};

  globalThis.__codexOut = [];
  globalThis.__codexIn = [];
  let rpcCount = 0;

  // ------------------------------------------------------------------ inbound
  // The renderer validates inbound messages with `event.source === null` (it
  // skips the origin check in that case), which is exactly what a synthesized
  // MessageEvent gives us.
  const dispatchInbound = (payload) => {
    globalThis.__codexIn.push(payload);
    window.dispatchEvent(new MessageEvent("message", { data: payload }));
  };

  const forwardRequest = (msg) => {
    const { id, method, params } = msg.request;
    rpcCount += 1;
    if (rpcCount <= 500) console.info("[codex-web] rpc ->", method);
    fetch("/__codex_rpc", {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify({ method: method, params: params ?? {} }),
    })
      .then((res) => res.json())
      .then((body) => {
        // The renderer's app-server request client reads the reply from
        // `message: { id, result | error }`. `response` is kept alongside it
        // because the app-host side of the same bus uses that spelling.
        const message =
          body && body.error
            ? { id: id, error: { code: body.error.code ?? -32000, message: body.error.message ?? "rpc failed" } }
            : { id: id, result: body ? body.result : null };
        dispatchInbound({
          type: "mcp-response",
          hostId: msg.hostId,
          message: message,
          response: message,
          requestMethod: method,
          receivedAtMs: Date.now(),
        });
      })
      .catch((err) => {
        const message = { id: id, error: { code: -32000, message: String((err && err.message) || err) } };
        dispatchInbound({
          type: "mcp-response",
          hostId: msg.hostId,
          message: message,
          response: message,
          requestMethod: method,
          receivedAtMs: Date.now(),
        });
      });
    return Promise.resolve();
  };

  // ---------------------------------------------------------------- events
  // Everything the app server says on its own initiative — streaming deltas,
  // turn progress, server-initiated approval prompts — arrives on this
  // long-poll. The renderer subscribes to it as `mcp-notification`.
  globalThis.__codexEvents = [];
  let polling = false;

  const pumpEvents = async () => {
    if (polling) return;
    polling = true;
    while (polling) {
      try {
        const res = await fetch("/__codex_events", { cache: "no-store" });
        const body = await res.json();
        for (const event of body.events || []) {
          globalThis.__codexEvents.push(event);
          if (globalThis.__codexEvents.length > 400) globalThis.__codexEvents.shift();
          if (event.id != null) {
            // Server-initiated request: the renderer owns the answer path, which
            // this shim does not model yet. Keep it visible instead of dropping.
            globalThis.__codexServerRequests = globalThis.__codexServerRequests || [];
            globalThis.__codexServerRequests.push(event);
            continue;
          }
          dispatchInbound({
            type: "mcp-notification",
            hostId: "local",
            method: event.method,
            params: event.params ?? {},
          });
        }
      } catch {
        await new Promise((r) => setTimeout(r, 1000));
      }
    }
  };
  pumpEvents();

  // ------------------------------------------------------------- electron API
  // Synchronous getters first: callers treat these as plain values.
  const SYNC = {
    getInitialSidebarBootstrap: () => null,
    getConfig: () => null,
    getPlatform: () => "darwin",
    getLocale: () => "zh-CN",
    getVersion: () => "26.1021.31345",
    isPackaged: () => true,
    getWindowType: () => "electron",
    getZoomLevel: () => 0,
    isDeviceCheckSupported: () => true,
    isIntelMacBuild: () => false,
    getSystemThemeVariant: () => "light",
    subscribeToSystemThemeVariant: () => noop,
    getBuildFlavor: () => "codex",
    getAppSessionId: () => "codex-web-local",
    getDesktopUserAgent: () => navigator.userAgent,
    getSentryInitOptions: () => ({ appVersion: "26.1021.31345", buildFlavor: "codex" }),
    getSharedObjectSnapshotValue: () => undefined,
  };

  const makeBridge = () =>
    new Proxy(SYNC, {
      get(target, prop) {
        if (prop in target) return target[prop];
        if (prop === "then") return undefined; // never a thenable
        if (typeof prop === "symbol") return undefined;
        if (prop === "sendMessageFromView") {
          return (msg) => {
            globalThis.__codexOut.push(msg);
            if (msg && msg.type === "mcp-request" && msg.request && typeof msg.request.method === "string") {
              return forwardRequest(msg);
            }
            return Promise.resolve();
          };
        }
        // Unknown member: an inert async function, so feature probes see
        // "present" and promise chains stay valid.
        return () => Promise.resolve();
      },
      has: () => true,
    });

  if (typeof window.electronBridge === "undefined") window.electronBridge = makeBridge();
  if (typeof window.codexWindowType === "undefined") window.codexWindowType = "electron";
  if (typeof window.__SENTRY_IPC__ === "undefined") window.__SENTRY_IPC__ = { sendMessage: noop };
  window.__codexDesktop = window.__codexDesktop || {};

  // ------------------------------------------------------------- offline net
  // Nothing leaves the machine. Absolute URLs get a well-formed empty JSON body
  // so callers fail softly instead of hitting the CSP. The remaining browser
  // transports — XHR, sendBeacon, WebSocket, EventSource — are stubbed the same
  // way: local requests pass through, everything else succeeds locally with
  // empty data.
  const realFetch = window.fetch.bind(window);
  const isLocal = (url) =>
    !url ||
    url.startsWith("/") ||
    url.startsWith("data:") ||
    url.startsWith("blob:") ||
    url.startsWith(location.origin);

  window.fetch = (input, init) => {
    const url = typeof input === "string" ? input : (input && input.url) || "";
    if (isLocal(url)) return realFetch(input, init);
    console.info("[codex-web] outbound:", (init?.method || "GET"), url.slice(0, 140));
    const json = (obj, status = 200) =>
      Promise.resolve(new Response(typeof obj === "string" ? obj : JSON.stringify(obj), {
        status,
        headers: { "content-type": "application/json" },
      }));
    // Statsig telemetry hosts. The SDK requires its initialize payload to
    // carry `has_updates` (see _typedJsonParse), so hand back a valid empty
    // evaluation set — every gate then resolves to "off" locally and the SDK
    // completes initialization instead of retrying forever.
    if (/ab\.chatgpt\.com|api\.oaistatsig\.com|statsigcdn\.openai\.com/i.test(url)) {
      if (/\/initialize/i.test(url)) {
        return json({
          has_updates: true,
          hash_used: "djb2",
          time: Date.now(),
          feature_gates: {},
          dynamic_configs: {},
          layer_configs: {},
          param_stores: {},
        });
      }
      if (/sdk_exception/i.test(url)) {
        return Promise.resolve(new Response(null, { status: 204 }));
      }
      // rgstr / download_config_specs: accepted-and-empty.
      return Promise.resolve(new Response(null, { status: 202 }));
    }
    // Everything else: generic empty JSON success.
    return json({});
  };

  // XMLHttpRequest: same policy. A cross-origin send completes immediately
  // with `{}` and status 200, on the microtask queue so ordering stays sane.
  const XHR = window.XMLHttpRequest;
  if (XHR && XHR.prototype) {
    const openOrig = XHR.prototype.open;
    const sendOrig = XHR.prototype.send;
    XHR.prototype.open = function (method, url, ...rest) {
      this.__codexUrl = String(url ?? "");
      return openOrig.call(this, method, url, ...rest);
    };
    XHR.prototype.send = function (body) {
      if (isLocal(this.__codexUrl)) return sendOrig.call(this, body);
      const payload = this.responseType === "json" ? {} : "{}";
      queueMicrotask(() => {
        try {
          Object.defineProperty(this, "readyState", { value: 4, configurable: true });
          Object.defineProperty(this, "status", { value: 200, configurable: true });
          Object.defineProperty(this, "statusText", { value: "OK", configurable: true });
          Object.defineProperty(this, "responseText", { value: payload, configurable: true });
          Object.defineProperty(this, "response", { value: payload, configurable: true });
          Object.defineProperty(this, "responseURL", { value: this.__codexUrl, configurable: true });
          this.dispatchEvent(new Event("readystatechange"));
          this.dispatchEvent(new ProgressEvent("load"));
          this.dispatchEvent(new ProgressEvent("loadend"));
        } catch {
          /* the request object went away; nothing to satisfy */
        }
      });
    };
  }

  // sendBeacon is fire-and-forget by contract; "delivered" locally means dropped.
  try {
    if (navigator.sendBeacon) navigator.sendBeacon = () => true;
  } catch {
    /* some engines make it a getter; the CSP covers those */
  }

  // WebSocket: hand back a socket that is already closed. No network dial, no
  // browser console noise, and well-behaved clients see a terminal state.
  const RealWS = window.WebSocket;
  if (RealWS) {
    class ClosedSocket extends EventTarget {
      constructor(url) {
        super();
        this.url = String(url ?? "");
        this.readyState = 3; // CLOSED
        this.bufferedAmount = 0;
        this.extensions = "";
        this.protocol = "";
        this.binaryType = "blob";
        queueMicrotask(() => {
          this.dispatchEvent(new Event("error"));
          this.dispatchEvent(new CloseEvent("close", { wasClean: true, code: 1000 }));
        });
      }
      send() {
        throw new DOMException("The socket is closed.", "InvalidStateError");
      }
      close() {}
    }
    for (const k of ["CONNECTING", "OPEN", "CLOSING", "CLOSED"]) ClosedSocket[k] = RealWS[k];
    window.WebSocket = ClosedSocket;
  }

  // EventSource: a stream that closes immediately, for the same reason.
  if (window.EventSource) {
    class ClosedStream extends EventTarget {
      constructor(url) {
        super();
        this.url = String(url ?? "");
        this.readyState = 2; // CLOSED
        this.withCredentials = false;
        queueMicrotask(() => this.dispatchEvent(new Event("error")));
      }
      close() {}
    }
    window.EventSource = ClosedStream;
  }

  console.info("[codex-web] offline host shim installed");
})();

// ------------------------------------------------------------- config preseed
// The scope-query bridge only fetches from mounted React readers, and the
// config/effective + permission-profiles queries have no mounted reader in a
// browser fallback (no project tree, no workspace picker). Prime both from the
// local app server up front so the composer's agent-mode resolution sees real
// data on first render instead of a query that would stay pending forever.
(() => {
  const rpc = (method, params) =>
    fetch("/__codex_rpc", {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify({ method, params: params ?? null }),
    })
      .then((r) => r.json())
      .then((b) => (b && b.result ? b.result : null))
      .catch(() => null);

  globalThis.__codexCfg = null;
  globalThis.__codexPerms = null;

  rpc("config/read", { includeLayers: true, cwd: null }).then((r) => {
    if (r && r.config) {
      globalThis.__codexCfg = r;
      console.info("[codex-web] config preseeded");
    }
  });
  rpc("permissionProfile/list", { cursor: null, limit: 50, cwd: null }).then((r) => {
    if (r && Array.isArray(r.data)) {
      globalThis.__codexPerms = r.data;
      console.info("[codex-web] permission profiles preseeded");
    }
  });
})();