feat(provider): add The Old LLM (theoldllm) — free Playwright-backed provider (#3217)

Add The Old LLM (theoldllm) free browser-backed provider. Integrated into release/v3.8.11.

open-sse/config/providerRegistry.ts

@@ -4228,6 +4228,29 @@ const _REGISTRY_EAGER: Record<string, RegistryEntry> = {
       },
     ],
   },
+
+  theoldllm: {
+    id: "theoldllm",
+    alias: "tllm",
+    format: "openai",
+    executor: "theoldllm",
+    // Playwright-backed executor — no standard auth; uses embedded browser for token generation
+    baseUrl: "https://theoldllm.vercel.app/api/chatgpt",
+    baseUrls: ["https://theoldllm.vercel.app/api/chatgpt"],
+    authType: "none",
+    authHeader: "none",
+    models: [
+      { id: "GPT_5_4", name: "GPT-5.4 (The Old LLM 🆓)" },
+      { id: "GPT_4o", name: "GPT-4o (The Old LLM 🆓)" },
+      { id: "claude_opus_4", name: "Claude Opus 4 (The Old LLM 🆓)" },
+      { id: "claude_sonnet_4", name: "Claude Sonnet 4 (The Old LLM 🆓)" },
+      { id: "claude_haiku_3_5", name: "Claude Haiku 3.5 (The Old LLM 🆓)" },
+      { id: "deepseek_v4", name: "DeepSeek V4 (The Old LLM 🆓)" },
+      { id: "gemini_3_flash", name: "Gemini 3 Flash (The Old LLM 🆓)" },
+      { id: "gemini_3_pro", name: "Gemini 3 Pro (The Old LLM 🆓)" },
+    ],
+    passthroughModels: true,
+  },
 };
 
 export const REGISTRY: Record<string, RegistryEntry> = _REGISTRY_EAGER;

open-sse/executors/index.ts

@@ -47,6 +47,7 @@ import { KimiWebExecutor } from "./kimi-web.ts";
 import { DoubaoWebExecutor } from "./doubao-web.ts";
 import { QwenWebExecutor } from "./qwen-web.ts";
 import { KimiExecutor } from "./kimi.ts"
+import { TheOldLlmExecutor } from "./theoldllm.ts";
 
 const executors = {
   antigravity: new AntigravityExecutor(),
@@ -134,6 +135,8 @@ const executors = {
   db: new DoubaoWebExecutor(), // Alias
   "qwen-web": new QwenWebExecutor(),
   qw: new QwenWebExecutor(), // Alias
+  theoldllm: new TheOldLlmExecutor(),
+  tllm: new TheOldLlmExecutor(), // Alias
 };
 
 const defaultCache = new Map();
@@ -190,3 +193,4 @@ export { AdaptaWebExecutor } from "./adapta-web.ts";
 export { T3ChatWebExecutor } from "./t3-chat-web.ts";
 export { InnerAiExecutor } from "./inner-ai.ts";
 export { QwenWebExecutor } from "./qwen-web.ts";
+export { TheOldLlmExecutor } from "./theoldllm.ts";

open-sse/executors/theoldllm.ts

@@ -0,0 +1,473 @@
+import { BaseExecutor, type ExecuteInput } from "./base.ts";
+import type { ProviderCredentials } from "./base.ts";
+
+type BrowserRef = import("playwright").Browser;
+type PageRef = import("playwright").Page;
+
+const API_BASE = "https://theoldllm.vercel.app";
+const API_PATH = "/api/chatgpt";
+const API_URL = `${API_BASE}${API_PATH}`;
+const CHROME_UA =
+  "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36";
+
+// ── Model name mapping ────────────────────────────────────────────────────
+
+const GPT_MODELS: Record<string, string> = {
+  "gpt-5.4": "GPT_5_4",
+  "gpt-5.3": "GPT_5_3",
+  "gpt-5.2": "GPT_5_2",
+  "gpt-5.1": "GPT_5_1",
+  "gpt-5": "GPT_5",
+  "gpt5_4": "GPT_5_4",
+  "gpt5_3": "GPT_5_3",
+  "gpt5_2": "GPT_5_2",
+  "gpt5_1": "GPT_5_1",
+  "gpt_4o": "GPT_4O",
+  "gpt-4o": "GPT_4O",
+  "gpt_5_3": "GPT_5_3",
+  "gpt_5_2": "GPT_5_2",
+  "gpt_5_1": "GPT_5_1",
+  "gpt_5": "GPT_5",
+};
+
+const CLAUDE_NAMES: Record<string, string> = {
+  "claude-4.6-opus": "CLAUDE_4_6_OPUS",
+  "claude-4.6-sonnet": "CLAUDE_4_6_SONNET",
+  "claude-4.5-haiku": "CLAUDE_4_5_HAIKU",
+  "claude_opus_4": "CLAUDE_4_6_OPUS",
+  "claude_sonnet_4": "CLAUDE_4_6_SONNET",
+  "claude_haiku_3_5": "CLAUDE_4_5_HAIKU",
+  "claude opus 4": "CLAUDE_4_6_OPUS",
+  "claude sonnet 4": "CLAUDE_4_6_SONNET",
+  "claude haiku 3.5": "CLAUDE_4_5_HAIKU",
+};
+
+function mapModel(model: string): string {
+  const n = model.toLowerCase().trim();
+  const gptKey = n.replace(/[_\s]+/g, "-");
+  if (GPT_MODELS[gptKey]) return GPT_MODELS[gptKey];
+  const gptKey2 = n.replace(/[-\s]+/g, "_");
+  if (GPT_MODELS[gptKey2]) return GPT_MODELS[gptKey2];
+  if (CLAUDE_NAMES[n]) return CLAUDE_NAMES[n];
+  if (n.includes("claude")) {
+    if (n.includes("opus")) return "CLAUDE_4_6_OPUS";
+    if (n.includes("sonnet")) return "CLAUDE_4_6_SONNET";
+    if (n.includes("haiku")) return "CLAUDE_4_5_HAIKU";
+  }
+  if (n.includes("gpt") && n.includes("5")) return "GPT_5_4";
+  return "GPT_5_4";
+}
+
+// ── Token cache (exported for test pre-population) ────────────────────────
+
+const TOKEN_TTL_MS = 15 * 60 * 1000;
+
+export const tokenCache: { value: string; expiresAt: number } = {
+  value: "",
+  expiresAt: 0,
+};
+
+let tokenLock: Promise<void> | null = null;
+
+function getCachedToken(): string | null {
+  if (tokenCache.value && Date.now() < tokenCache.expiresAt) return tokenCache.value;
+  return null;
+}
+
+function setCachedToken(token: string): void {
+  tokenCache.value = token;
+  tokenCache.expiresAt = Date.now() + TOKEN_TTL_MS;
+}
+
+function invalidateToken(): void {
+  tokenCache.value = "";
+  tokenCache.expiresAt = 0;
+}
+
+// ── Playwright token capture (fallback only) ──────────────────────────────
+
+let _browser: Promise<BrowserRef> | null = null;
+let _cleanupRegistered = false;
+
+function registerCleanup(): void {
+  if (_cleanupRegistered) return;
+  _cleanupRegistered = true;
+  const cleanup = () => {
+    if (_browser) {
+      _browser.then((b) => b.close().catch(() => {})).catch(() => {});
+      _browser = null;
+    }
+  };
+  process.on("exit", cleanup);
+  process.on("SIGTERM", () => { cleanup(); process.exit(0); });
+  process.on("SIGINT", () => { cleanup(); process.exit(0); });
+}
+
+async function getBrowser(): Promise<BrowserRef> {
+  if (_browser) {
+    try {
+      const b = await _browser;
+      if (b.isConnected()) return b;
+    } catch {
+      _browser = null;
+    }
+  }
+  registerCleanup();
+  _browser = (async () => {
+    const { chromium } = await import("playwright");
+    return await chromium.launch({
+      headless: true,
+      args: [
+        "--disable-blink-features=AutomationControlled",
+        "--no-sandbox",
+        "--disable-setuid-sandbox",
+        "--disable-dev-shm-usage",
+        "--window-size=1280,1024",
+      ],
+    });
+  })();
+  return _browser;
+}
+
+async function captureTokenViaBrowser(): Promise<string> {
+  const browser = await getBrowser();
+  const context = await browser.newContext({
+    userAgent: CHROME_UA,
+    viewport: { width: 1280, height: 1024 },
+  });
+  await context.addInitScript(() => {
+    Object.defineProperty(navigator, "webdriver", { get: () => false });
+    (window as any).chrome = { runtime: {} };
+  });
+
+  const page = await context.newPage();
+  const navTimeout = Number(process.env.THEOLDLLM_NAV_TIMEOUT_MS) || 30_000;
+
+  try {
+    await page.goto(API_BASE, { waitUntil: "domcontentloaded", timeout: navTimeout });
+
+    const textareaFound = await page
+      .waitForSelector("textarea", { timeout: navTimeout })
+      .then(() => true)
+      .catch(() => false);
+
+    if (!textareaFound) {
+      const newChat = page.locator("button", { hasText: "New chat" });
+      await newChat.first().waitFor({ state: "visible", timeout: 5_000 }).catch(() => {});
+      if (await newChat.first().isVisible().catch(() => false)) {
+        await newChat.first().click();
+        await page.waitForTimeout(1_500);
+        await page.waitForSelector("textarea", { timeout: 10_000 }).catch(() => {});
+      }
+    }
+
+    await page.waitForTimeout(3_000);
+
+    const capturedToken = await new Promise<string>((resolve, reject) => {
+      const timeout = setTimeout(() => reject(new Error("Token capture timed out")), 25_000);
+
+      page.route("**/api/chatgpt", async (route) => {
+        clearTimeout(timeout);
+        const t = route.request().headers()["x-request-token"];
+        try { await route.abort("blockedbyclient"); } catch {}
+        resolve(t);
+      });
+
+      (async () => {
+        try {
+          const ta = page.locator("textarea").first();
+          await ta.waitFor({ state: "visible", timeout: 10_000 });
+          await ta.click();
+          await ta.fill("hello");
+          await page.waitForTimeout(300);
+          await ta.press("Enter");
+        } catch (err) {
+          clearTimeout(timeout);
+          reject(new Error(`SPA send failed: ${err instanceof Error ? err.message : String(err)}`));
+        }
+      })();
+    });
+
+    return capturedToken;
+  } finally {
+    await page.close().catch(() => {});
+  }
+}
+
+// Serialize concurrent token refreshes so only one Playwright capture runs
+async function acquireToken(): Promise<string> {
+  const cached = getCachedToken();
+  if (cached) return cached;
+
+  // Wait for in-flight refresh
+  if (tokenLock) {
+    await tokenLock;
+    const retry = getCachedToken();
+    if (retry) return retry;
+  }
+
+  // Perform refresh under lock
+  let resolveLock!: () => void;
+  tokenLock = new Promise<void>((r) => { resolveLock = r; });
+
+  try {
+    const t = await captureTokenViaBrowser();
+    setCachedToken(t);
+    return t;
+  } finally {
+    tokenLock = null;
+    resolveLock();
+  }
+}
+
+// ── Direct Node.js fetch (fast path) ──────────────────────────────────────
+
+async function directFetch(
+  token: string,
+  reqBody: Record<string, unknown>,
+  signal?: AbortSignal | null,
+): Promise<Response> {
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), 120_000);
+  const onSignal = signal
+    ? () => controller.abort(signal.reason)
+    : undefined;
+  signal?.addEventListener("abort", onSignal!, { once: true });
+
+  try {
+    return await fetch(API_URL, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        "X-Client-Version": "3.8.4",
+        "X-Request-Token": token,
+        "User-Agent": CHROME_UA,
+      },
+      body: JSON.stringify(reqBody),
+      signal: controller.signal,
+    });
+  } finally {
+    clearTimeout(timer);
+    if (onSignal) signal?.removeEventListener("abort", onSignal);
+  }
+}
+
+function isTokenRejected(status: number, body: string): boolean {
+  if (status === 401 || status === 403) return true;
+  try {
+    const p = JSON.parse(body);
+    return (
+      p?.error?.type === "access_denied" ||
+      (typeof p?.error === "string" && /blocked|denied|invalid/i.test(p.error))
+    );
+  } catch {
+    return false;
+  }
+}
+
+// ── SSE helpers ───────────────────────────────────────────────────────────
+
+function parseSseContent(sseText: string): string {
+  let content = "";
+  for (const line of sseText.split("\n")) {
+    if (line.startsWith("data: ") && line !== "data: [DONE]") {
+      try {
+        const d = JSON.parse(line.slice(6));
+        content += d.choices?.[0]?.delta?.content || d.choices?.[0]?.delta?.text || "";
+      } catch {}
+    }
+  }
+  return content;
+}
+
+function buildChatCompletion(content: string, model: string): string {
+  return JSON.stringify({
+    id: `chatcmpl-${Date.now()}`,
+    object: "chat.completion",
+    created: Math.floor(Date.now() / 1000),
+    model: mapModel(model),
+    choices: [{ index: 0, message: { role: "assistant", content }, finish_reason: "stop" }],
+    usage: { prompt_tokens: 0, completion_tokens: 0, total_tokens: 0 },
+  });
+}
+
+function buildErrorResponse(status: number, body: string): string {
+  let detail = body;
+  for (const line of body.split("\n")) {
+    if (line.startsWith("data: ") && line !== "data: [DONE]") {
+      try {
+        const p = JSON.parse(line.slice(6));
+        if (p.error) { detail = JSON.stringify(p.error); break; }
+      } catch {}
+    }
+  }
+  return JSON.stringify({
+    error: { message: detail, type: "upstream_error", code: `HTTP_${status}` },
+  });
+}
+
+// ── Executor ──────────────────────────────────────────────────────────────
+
+export class TheOldLlmExecutor extends BaseExecutor {
+  constructor() {
+    super("theoldllm", { format: "openai" });
+  }
+
+  buildUrl(_model: string, _stream: boolean): string {
+    return API_URL;
+  }
+
+  buildHeaders(_credentials: ProviderCredentials): Record<string, string> {
+    return {
+      "Content-Type": "application/json",
+      "X-Client-Version": "3.8.4",
+      "User-Agent": CHROME_UA,
+    };
+  }
+
+  transformRequest(model: string, body: unknown, _stream: boolean): unknown {
+    if (typeof body === "object" && body !== null) {
+      return { ...(body as Record<string, unknown>), model: mapModel(model) };
+    }
+    return body;
+  }
+
+  async testConnection(
+    _credentials: ProviderCredentials,
+    _signal?: AbortSignal | null,
+    log?: ExecuteInput["log"],
+  ): Promise<boolean> {
+    const token = getCachedToken();
+    try {
+      const resp = await fetch(API_URL, {
+        method: "POST",
+        headers: {
+          "Content-Type": "application/json",
+          "X-Client-Version": "3.8.4",
+          ...(token ? { "X-Request-Token": token } : {}),
+          "User-Agent": CHROME_UA,
+        },
+        body: JSON.stringify({
+          model: "GPT_5_4",
+          messages: [{ role: "user", content: "ping" }],
+          stream: false,
+        }),
+        signal: _signal ?? undefined,
+      });
+      return resp.status === 200;
+    } catch {
+      log?.warn?.("THEOLDLLM", "testConnection network error");
+      return false;
+    }
+  }
+
+  async execute(input: ExecuteInput): Promise<{
+    response: Response;
+    url: string;
+    headers: Record<string, string>;
+    transformedBody: unknown;
+  }> {
+    const { model, stream, body, signal, log } = input;
+    const encoder = new TextEncoder();
+
+    if (signal?.aborted) {
+      return {
+        response: new Response(encoder.encode(JSON.stringify({
+          error: { message: "Request aborted", type: "abort", code: "ABORTED" },
+        })), { status: 499, headers: { "Content-Type": "application/json" } }),
+        url: API_URL,
+        headers: this.buildHeaders(input.credentials),
+        transformedBody: body,
+      };
+    }
+
+    try {
+      const reqBody = {
+        ...(body as Record<string, unknown>),
+        model: mapModel(model),
+        stream: true,
+      };
+
+      let token = getCachedToken();
+      let upstream: Response;
+
+      if (token) {
+        log?.debug?.("THEOLDLLM", "Using cached token — direct fetch");
+        upstream = await directFetch(token, reqBody, signal);
+      } else {
+        log?.info?.("THEOLDLLM", "No cached token — capturing via Playwright…");
+        try {
+          token = await acquireToken();
+        } catch (capErr) {
+          throw new Error(
+            `Token capture failed: ${capErr instanceof Error ? capErr.message : String(capErr)}`,
+          );
+        }
+        log?.info?.("THEOLDLLM", `Token captured: ${token.slice(0, 20)}…`);
+        upstream = await directFetch(token, reqBody, signal);
+      }
+
+      const upstreamBody = await upstream.text();
+
+      if (isTokenRejected(upstream.status, upstreamBody)) {
+        log?.warn?.("THEOLDLLM", `Token rejected (${upstream.status}), refreshing…`);
+        invalidateToken();
+        try {
+          token = await acquireToken();
+          log?.info?.("THEOLDLLM", `Token refreshed: ${token.slice(0, 20)}…`);
+        } catch {
+          log?.warn?.("THEOLDLLM", "Token refresh failed, retrying with existing token");
+        }
+        upstream = await directFetch(token, reqBody, signal);
+      }
+
+      const finalBody = await upstream.text();
+
+      if (upstream.status === 200 && finalBody) {
+        const payload = stream
+          ? finalBody
+          : buildChatCompletion(parseSseContent(finalBody), model);
+        return {
+          response: new Response(encoder.encode(payload), {
+            status: 200,
+            headers: {
+              "Content-Type": stream ? "text/event-stream" : "application/json",
+              "Cache-Control": "no-cache",
+            },
+          }),
+          url: API_URL,
+          headers: this.buildHeaders(input.credentials),
+          transformedBody: body,
+        };
+      }
+
+      return {
+        response: new Response(encoder.encode(buildErrorResponse(upstream.status, finalBody)), {
+          status: upstream.status,
+          headers: { "Content-Type": "application/json" },
+        }),
+        url: API_URL,
+        headers: this.buildHeaders(input.credentials),
+        transformedBody: body,
+      };
+    } catch (err) {
+      const msg = err instanceof Error ? err.message : String(err);
+      log?.error?.("THEOLDLLM", `Executor error: ${msg}`);
+      return {
+        response: new Response(
+          encoder.encode(
+            JSON.stringify({
+              error: { message: msg, type: "upstream_error", code: "EXECUTOR_ERROR" },
+            }),
+          ),
+          { status: 502, headers: { "Content-Type": "application/json" } },
+        ),
+        url: API_URL,
+        headers: this.buildHeaders(input.credentials),
+        transformedBody: body,
+      };
+    }
+  }
+}
+
+export default TheOldLlmExecutor;

src/shared/constants/providers.ts

@@ -58,6 +58,21 @@ export const NOAUTH_PROVIDERS = {
     freeNote: "Free — anonymous access to multiple AI models via DuckDuckGo.",
     authHint: "No credentials required — DuckDuckGo AI Chat is anonymous and free.",
   },
+  theoldllm: {
+    id: "theoldllm",
+    alias: "tllm",
+    name: "The Old LLM (Free)",
+    icon: "auto_awesome",
+    color: "#8B5CF6",
+    textIcon: "TL",
+    website: "https://theoldllm.vercel.app",
+    noAuth: true,
+    hasFree: true,
+    freeNote:
+      "Free — GPT-5.4, Claude 4.6 Opus/Sonnet/Haiku, + more. No API key — tokens auto-generated via browser.",
+    authHint:
+      "No credentials required. The executor auto-generates access tokens via an embedded Playwright browser instance.",
+  },
   "veoaifree-web": {
     id: "veoaifree-web",
     alias: "veo-free",
@@ -536,7 +551,7 @@ export const WEB_COOKIE_PROVIDERS = {
       "Open chat.qwen.ai, log in, then open DevTools → Application → Local Storage → " +
       'copy the "token" value (or use tongyi_sso_ticket cookie as Bearer token).',
   },
-};
+  };
 
 // API Key Providers
 export const APIKEY_PROVIDERS = {

tests/theoldllm-stress.test.ts

@@ -0,0 +1,246 @@
+import { describe, it, beforeEach } from "node:test";
+import assert from "node:assert";
+import { TheOldLlmExecutor, tokenCache } from "../open-sse/executors/theoldllm.ts";
+
+const executor = new TheOldLlmExecutor();
+
+const MOCK_SSE = [
+  'data: {"choices":[{"delta":{"content":"hi"},"index":0,"finish_reason":null}]}',
+  "data: [DONE]",
+  "",
+].join("\n");
+
+const MOCK_ERR = JSON.stringify({
+  error: { message: "auth", type: "access_denied" },
+});
+
+function makeResponse(status: number, body = MOCK_SSE) {
+  return {
+    status,
+    ok: status < 300,
+    statusText: status < 300 ? "OK" : "Error",
+    headers: new Map<string, string>([["content-type", "application/json"]]),
+    text: async () => body,
+  } as unknown as Response;
+}
+
+function warmTokenCache() {
+  tokenCache.value = "test-token-abc123";
+  tokenCache.expiresAt = Date.now() + 15 * 60 * 1000;
+}
+
+function clearTokenCache() {
+  tokenCache.value = "";
+  tokenCache.expiresAt = 0;
+}
+
+describe("TheOldLlmExecutor", () => {
+  it("buildHeaders returns static upstream headers", () => {
+    const headers = (executor as any).buildHeaders({});
+    assert.strictEqual(headers["Content-Type"], "application/json");
+    assert.ok(
+      headers["User-Agent"].includes("Chrome/"),
+      `expected Chrome UA, got ${headers["User-Agent"]}`,
+    );
+    assert.ok(
+      headers["User-Agent"].includes("Mozilla/5.0"),
+      `expected Mozilla UA, got ${headers["User-Agent"]}`,
+    );
+  });
+
+  it("maps model aliases to upstream slugs", () => {
+    const cases: Record<string, string> = {
+      "gpt-5.4": "GPT_5_4",
+      "GPT_5_3": "GPT_5_3",
+      "gpt_5_2": "GPT_5_2",
+      "gpt-4o": "GPT_4O",
+      "claude-4.6-opus": "CLAUDE_4_6_OPUS",
+      "claude sonnet 4": "CLAUDE_4_6_SONNET",
+      "claude_haiku_3_5": "CLAUDE_4_5_HAIKU",
+      "weird-model": "GPT_5_4",
+    };
+
+    const transformRequest = (executor as any).transformRequest.bind(
+      executor,
+    ) as (
+      model: string,
+      body: Record<string, unknown>,
+      stream: boolean,
+    ) => Record<string, unknown>;
+
+    for (const [model, expected] of Object.entries(cases)) {
+      const updated = transformRequest(model, { model, messages: [] }, true);
+      assert.strictEqual(
+        updated.model,
+        expected,
+        `model ${model} mapped to ${expected}, got ${updated.model}`,
+      );
+    }
+  });
+
+  it("returns true on 200 and false on 401 for testConnection", async () => {
+    const originalFetch = globalThis.fetch;
+    try {
+      globalThis.fetch = async () => makeResponse(200) as any;
+      assert.strictEqual(
+        await executor.testConnection({}, null, {
+          info: () => {},
+          warn: () => {},
+          error: () => {},
+          debug: () => {},
+        }),
+        true,
+      );
+
+      globalThis.fetch = async () => makeResponse(401) as any;
+      assert.strictEqual(
+        await executor.testConnection({}, null, {
+          info: () => {},
+          warn: () => {},
+          error: () => {},
+          debug: () => {},
+        }),
+        false,
+      );
+    } finally {
+      globalThis.fetch = originalFetch;
+    }
+  });
+
+  it("retries once after 401 then succeeds", async () => {
+    const originalFetch = globalThis.fetch;
+    warmTokenCache();
+    try {
+      let calls = 0;
+      const responses = [
+        () => makeResponse(401, MOCK_ERR),
+        () => makeResponse(200, MOCK_SSE),
+      ];
+
+      globalThis.fetch = async () =>
+        responses[
+          calls++ < responses.length ? calls - 1 : responses.length - 1
+        ]() as any;
+
+      const result = await executor.execute({
+        model: "gpt-5.4",
+        body: { messages: [{ role: "user", content: "hai" }], stream: true },
+        stream: true,
+        signal: null,
+        credentials: {},
+        log: {
+          debug: () => {},
+          info: () => {},
+          warn: () => {},
+          error: () => {},
+        },
+      });
+
+      assert.strictEqual((result as any).response.status, 200);
+      assert.ok(calls >= 2, `expected >=2 fetch calls, got ${calls}`);
+    } finally {
+      globalThis.fetch = originalFetch;
+      clearTokenCache();
+    }
+  });
+
+  it("lets cancellation abort before upstream work", async () => {
+    const controller = new AbortController();
+    controller.abort(new Error("cancelled"));
+    warmTokenCache();
+
+    let fetchCalls = 0;
+    const originalFetch = globalThis.fetch;
+    globalThis.fetch = async () => {
+      fetchCalls++;
+      return makeResponse(200) as any;
+    };
+
+    try {
+      await executor.execute({
+        model: "gpt-5.4",
+        body: { messages: [{ role: "user", content: "ping" }], stream: true },
+        stream: true,
+        signal: controller.signal,
+        credentials: {},
+        log: {
+          debug: () => {},
+          info: () => {},
+          warn: () => {},
+          error: () => {},
+        },
+      });
+
+      assert.strictEqual(fetchCalls, 0);
+    } finally {
+      globalThis.fetch = originalFetch;
+      clearTokenCache();
+    }
+  });
+
+  it("handles concurrent calls with cached token", async () => {
+    const originalFetch = globalThis.fetch;
+    warmTokenCache();
+    try {
+      let fetchCalls = 0;
+
+      globalThis.fetch = async () => {
+        fetchCalls++;
+        return makeResponse(200) as any;
+      };
+
+      const requests = Array.from({ length: 4 }, () =>
+        executor.execute({
+          model: "gpt-5.4",
+          body: { messages: [{ role: "user", content: "ping" }], stream: true },
+          stream: true,
+          signal: null,
+          credentials: {},
+          log: {
+            debug: () => {},
+            info: () => {},
+            warn: () => {},
+            error: () => {},
+          },
+        }),
+      );
+
+      await Promise.all(requests);
+      assert.ok(fetchCalls >= 1, `expected >=1 fetch calls, got ${fetchCalls}`);
+    } finally {
+      globalThis.fetch = originalFetch;
+      clearTokenCache();
+    }
+  });
+
+  it("fast fails on network error", async () => {
+    const originalFetch = globalThis.fetch;
+    warmTokenCache();
+    try {
+      globalThis.fetch = async () => {
+        const error = new Error("ECONNREFUSED");
+        (error as any).cause = new Error("ECONNREFUSED");
+        throw error;
+      };
+
+      const result = await executor.execute({
+        model: "gpt-5.4",
+        body: { messages: [{ role: "user", content: "ping" }], stream: true },
+        stream: true,
+        signal: null,
+        credentials: {},
+        log: {
+          debug: () => {},
+          info: () => {},
+          warn: () => {},
+          error: () => {},
+        },
+      });
+
+      assert.strictEqual((result as any).response.status, 502);
+    } finally {
+      globalThis.fetch = originalFetch;
+      clearTokenCache();
+    }
+  });
+});