diff --git a/packages/ai/moonshot/src/index.test.ts b/packages/ai/moonshot/src/index.test.ts
index 91ea1547..cc2a9ab9 100644
--- a/packages/ai/moonshot/src/index.test.ts
+++ b/packages/ai/moonshot/src/index.test.ts
@@ -54,14 +54,14 @@ describe('Moonshot OpenAI-compatible generation', () => {
         temperature: 0.2,
         extra: { thinking: { type: 'disabled' } },
       },
-      {}
+      { baseUrl: 'https://moonshot.test/v1/' }
     );
 
     expect(fetchMock).toHaveBeenCalledOnce();
     const call = fetchMock.mock.calls[0];
     expect(call).toBeDefined();
     const [url, request] = call!;
-    expect(url).toBe('https://api.moonshot.ai/v1/chat/completions');
+    expect(url).toBe('https://moonshot.test/v1/chat/completions');
     expect(request.headers.authorization).toBe('Bearer test-key');
     expect(JSON.parse(request.body)).toEqual({
       model: 'kimi-k2.5',
@@ -81,6 +81,22 @@ describe('Moonshot OpenAI-compatible generation', () => {
     });
   });
 
+  it.each([
+    ['missing scheme', 'moonshot.test/v1'],
+    ['ftp scheme', 'ftp://moonshot.test/v1'],
+    ['credentials', 'https://user:pass@moonshot.test/v1'],
+    ['query string', 'https://moonshot.test/v1?token=secret'],
+    ['fragment', 'https://moonshot.test/v1#chat'],
+  ])('rejects unclean custom baseUrl values: %s', async (_label, baseUrl) => {
+    const fetchMock = vi.fn();
+    vi.stubGlobal('fetch', fetchMock);
+
+    await expect(adapter.generate(ctx(), 'hello', {}, { baseUrl })).rejects.toThrow(
+      /Moonshot baseUrl/
+    );
+    expect(fetchMock).not.toHaveBeenCalled();
+  });
+
   it('includes status and response body excerpt on errors', async () => {
     vi.stubGlobal('fetch', vi.fn().mockResolvedValue({
       ok: false,
diff --git a/packages/ai/moonshot/src/index.ts b/packages/ai/moonshot/src/index.ts
index 7a46ca75..f3f89892 100644
--- a/packages/ai/moonshot/src/index.ts
+++ b/packages/ai/moonshot/src/index.ts
@@ -24,7 +24,8 @@ export default defineAi<Config>({
     if (opts.system) messages.push({ role: 'system', content: opts.system });
     messages.push({ role: 'user', content: prompt });
 
-    const res = await fetch(`${config.baseUrl ?? DEFAULT_BASE}/chat/completions`, {
+    const baseUrl = cleanBaseUrl(config.baseUrl ?? DEFAULT_BASE);
+    const res = await fetch(`${baseUrl}/chat/completions`, {
       method: 'POST',
       headers: {
         authorization: `Bearer ${apiKey}`,
@@ -81,3 +82,22 @@ interface MoonshotChatResponse {
     completion_tokens?: number;
   };
 }
+
+function cleanBaseUrl(value: string): string {
+  let url: URL;
+  try {
+    url = new URL(value);
+  } catch {
+    throw new Error('Moonshot baseUrl must be a valid URL');
+  }
+
+  if (url.protocol !== 'https:' && url.protocol !== 'http:') {
+    throw new Error('Moonshot baseUrl must use http or https');
+  }
+
+  if (url.username || url.password || url.search || url.hash) {
+    throw new Error('Moonshot baseUrl must be a clean API base without credentials, query, or hash');
+  }
+
+  return url.toString().replace(/\/+$/, '');
+}