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/agents/pi-embedded-runner.test.ts

@@ -104,7 +104,7 @@ beforeAll(async () => {
   workspaceDir = path.join(tempRoot, "workspace");
   await fs.mkdir(agentDir, { recursive: true });
   await fs.mkdir(workspaceDir, { recursive: true });
-}, 20_000);
+}, 60_000);
 
 afterAll(async () => {
   if (!tempRoot) {

src/agents/pi-embedded-runner/model.test.ts

@@ -242,6 +242,41 @@ describe("resolveModel", () => {
     });
   });
 
+  it("builds a zai forward-compat fallback for glm-5", () => {
+    const templateModel = {
+      id: "glm-4.7",
+      name: "GLM-4.7",
+      provider: "zai",
+      api: "openai-completions",
+      baseUrl: "https://api.z.ai/api/paas/v4",
+      reasoning: true,
+      input: ["text"] as const,
+      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+      contextWindow: 200000,
+      maxTokens: 131072,
+    };
+
+    vi.mocked(discoverModels).mockReturnValue({
+      find: vi.fn((provider: string, modelId: string) => {
+        if (provider === "zai" && modelId === "glm-4.7") {
+          return templateModel;
+        }
+        return null;
+      }),
+    } as unknown as ReturnType<typeof discoverModels>);
+
+    const result = resolveModel("zai", "glm-5", "/tmp/agent");
+
+    expect(result.error).toBeUndefined();
+    expect(result.model).toMatchObject({
+      provider: "zai",
+      id: "glm-5",
+      api: "openai-completions",
+      baseUrl: "https://api.z.ai/api/paas/v4",
+      reasoning: true,
+    });
+  });
+
   it("keeps unknown-model errors for non-gpt-5 openai-codex ids", () => {
     const result = resolveModel("openai-codex", "gpt-4.1-mini", "/tmp/agent");
     expect(result.model).toBeUndefined();

src/agents/pi-embedded-runner/model.ts

@@ -114,6 +114,51 @@ function resolveAnthropicOpus46ForwardCompatModel(
   return undefined;
 }
 
+// Z.ai's GLM-5 may not be present in pi-ai's built-in model catalog yet.
+// When a user configures zai/glm-5 without a models.json entry, clone glm-4.7 as a forward-compat fallback.
+const ZAI_GLM5_MODEL_ID = "glm-5";
+const ZAI_GLM5_TEMPLATE_MODEL_IDS = ["glm-4.7"] as const;
+
+function resolveZaiGlm5ForwardCompatModel(
+  provider: string,
+  modelId: string,
+  modelRegistry: ModelRegistry,
+): Model<Api> | undefined {
+  if (normalizeProviderId(provider) !== "zai") {
+    return undefined;
+  }
+  const trimmed = modelId.trim();
+  const lower = trimmed.toLowerCase();
+  if (lower !== ZAI_GLM5_MODEL_ID && !lower.startsWith(`${ZAI_GLM5_MODEL_ID}-`)) {
+    return undefined;
+  }
+
+  for (const templateId of ZAI_GLM5_TEMPLATE_MODEL_IDS) {
+    const template = modelRegistry.find("zai", templateId) as Model<Api> | null;
+    if (!template) {
+      continue;
+    }
+    return normalizeModelCompat({
+      ...template,
+      id: trimmed,
+      name: trimmed,
+      reasoning: true,
+    } as Model<Api>);
+  }
+
+  return normalizeModelCompat({
+    id: trimmed,
+    name: trimmed,
+    api: "openai-completions",
+    provider: "zai",
+    reasoning: true,
+    input: ["text"],
+    cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+    contextWindow: DEFAULT_CONTEXT_TOKENS,
+    maxTokens: DEFAULT_CONTEXT_TOKENS,
+  } as Model<Api>);
+}
+
 // google-antigravity's model catalog in pi-ai can lag behind the actual platform.
 // When a google-antigravity model ID contains "opus-4-6" (or "opus-4.6") but isn't
 // in the registry yet, clone the opus-4-5 template so the correct api
@@ -242,6 +287,10 @@ export function resolveModel(
     if (antigravityForwardCompat) {
       return { model: antigravityForwardCompat, authStorage, modelRegistry };
     }
+    const zaiForwardCompat = resolveZaiGlm5ForwardCompatModel(provider, modelId, modelRegistry);
+    if (zaiForwardCompat) {
+      return { model: zaiForwardCompat, authStorage, modelRegistry };
+    }
     const providerCfg = providers[provider];
     if (providerCfg || modelId.startsWith("mock-")) {
       const fallbackModel: Model<Api> = normalizeModelCompat({