feat(zai): auto-detect endpoint + default glm-5 (#14786)

* feat(zai): auto-detect endpoint + default glm-5

* test: fix Z.AI default endpoint expectation (#14786)

* test: bump embedded runner beforeAll timeout

* chore: update changelog for Z.AI GLM-5 autodetect (#14786)

* chore: resolve changelog merge conflict with main (#14786)

* chore: append changelog note for #14786 without merge conflict

* chore: sync changelog with main to resolve merge conflict

src/commands/zai-endpoint-detect.ts

@@ -0,0 +1,148 @@
+import { fetchWithTimeout } from "../utils/fetch-timeout.js";
+import {
+  ZAI_CN_BASE_URL,
+  ZAI_CODING_CN_BASE_URL,
+  ZAI_CODING_GLOBAL_BASE_URL,
+  ZAI_GLOBAL_BASE_URL,
+} from "./onboard-auth.models.js";
+
+export type ZaiEndpointId = "global" | "cn" | "coding-global" | "coding-cn";
+
+export type ZaiDetectedEndpoint = {
+  endpoint: ZaiEndpointId;
+  /** Provider baseUrl to store in config. */
+  baseUrl: string;
+  /** Recommended default model id for that endpoint. */
+  modelId: string;
+  /** Human-readable note explaining the choice. */
+  note: string;
+};
+
+type ProbeResult =
+  | { ok: true }
+  | {
+      ok: false;
+      status?: number;
+      errorCode?: string;
+      errorMessage?: string;
+    };
+
+async function probeZaiChatCompletions(params: {
+  baseUrl: string;
+  apiKey: string;
+  modelId: string;
+  timeoutMs: number;
+  fetchFn?: typeof fetch;
+}): Promise<ProbeResult> {
+  try {
+    const res = await fetchWithTimeout(
+      `${params.baseUrl}/chat/completions`,
+      {
+        method: "POST",
+        headers: {
+          authorization: `Bearer ${params.apiKey}`,
+          "content-type": "application/json",
+        },
+        body: JSON.stringify({
+          model: params.modelId,
+          stream: false,
+          max_tokens: 1,
+          messages: [{ role: "user", content: "ping" }],
+        }),
+      },
+      params.timeoutMs,
+      params.fetchFn,
+    );
+
+    if (res.ok) {
+      return { ok: true };
+    }
+
+    let errorCode: string | undefined;
+    let errorMessage: string | undefined;
+    try {
+      const json = (await res.json()) as {
+        error?: { code?: unknown; message?: unknown };
+        msg?: unknown;
+        message?: unknown;
+      };
+      const code = json?.error?.code;
+      const msg = json?.error?.message ?? json?.msg ?? json?.message;
+      if (typeof code === "string") {
+        errorCode = code;
+      } else if (typeof code === "number") {
+        errorCode = String(code);
+      }
+      if (typeof msg === "string") {
+        errorMessage = msg;
+      }
+    } catch {
+      // ignore
+    }
+
+    return { ok: false, status: res.status, errorCode, errorMessage };
+  } catch {
+    return { ok: false };
+  }
+}
+
+export async function detectZaiEndpoint(params: {
+  apiKey: string;
+  timeoutMs?: number;
+  fetchFn?: typeof fetch;
+}): Promise<ZaiDetectedEndpoint | null> {
+  // Never auto-probe in vitest; it would create flaky network behavior.
+  if (process.env.VITEST && !params.fetchFn) {
+    return null;
+  }
+
+  const timeoutMs = params.timeoutMs ?? 5_000;
+
+  // Prefer GLM-5 on the general API endpoints.
+  const glm5: Array<{ endpoint: ZaiEndpointId; baseUrl: string }> = [
+    { endpoint: "global", baseUrl: ZAI_GLOBAL_BASE_URL },
+    { endpoint: "cn", baseUrl: ZAI_CN_BASE_URL },
+  ];
+  for (const candidate of glm5) {
+    const result = await probeZaiChatCompletions({
+      baseUrl: candidate.baseUrl,
+      apiKey: params.apiKey,
+      modelId: "glm-5",
+      timeoutMs,
+      fetchFn: params.fetchFn,
+    });
+    if (result.ok) {
+      return {
+        endpoint: candidate.endpoint,
+        baseUrl: candidate.baseUrl,
+        modelId: "glm-5",
+        note: `Verified GLM-5 on ${candidate.endpoint} endpoint.`,
+      };
+    }
+  }
+
+  // Fallback: Coding Plan endpoint (GLM-5 not available there).
+  const coding: Array<{ endpoint: ZaiEndpointId; baseUrl: string }> = [
+    { endpoint: "coding-global", baseUrl: ZAI_CODING_GLOBAL_BASE_URL },
+    { endpoint: "coding-cn", baseUrl: ZAI_CODING_CN_BASE_URL },
+  ];
+  for (const candidate of coding) {
+    const result = await probeZaiChatCompletions({
+      baseUrl: candidate.baseUrl,
+      apiKey: params.apiKey,
+      modelId: "glm-4.7",
+      timeoutMs,
+      fetchFn: params.fetchFn,
+    });
+    if (result.ok) {
+      return {
+        endpoint: candidate.endpoint,
+        baseUrl: candidate.baseUrl,
+        modelId: "glm-4.7",
+        note: "Coding Plan endpoint detected; GLM-5 is not available there. Defaulting to GLM-4.7.",
+      };
+    }
+  }
+
+  return null;
+}