fix byok-opencode: route non-OpenAI openai-protocol hosts to @ai-sdk/openai-compatible (#5344)

The BYOK OpenCode path mapped protocol "openai" straight to @ai-sdk/openai (Responses API /responses) for every host, so providers that only serve /chat/completions (DeepSeek, vLLM, etc.) 404 on /responses. Route non-api.openai.com openai-protocol hosts to @ai-sdk/openai-compatible; real OpenAI stays on @ai-sdk/openai. Adds a DeepSeek regression test and corrects the vLLM test to openai-compatible.

Author: JackChen-me

apps/daemon/src/runtimes/byok-opencode.ts

@@ -158,6 +158,15 @@ function isExactOrigin(value: string, origin: string): boolean {
   }
 }
 
+function isRealOpenAIHost(baseUrl: string): boolean {
+  if (!baseUrl) return true;
+  try {
+    return new URL(baseUrl).hostname === 'api.openai.com';
+  } catch {
+    return true;
+  }
+}
+
 function buildProviderEntry(
   protocol: ByokChatProviderConfig['protocol'],
   baseUrl: string,
@@ -207,11 +216,23 @@ function buildProviderEntry(
         },
       };
     case 'openai':
+      // Real OpenAI speaks the Responses API via @ai-sdk/openai. Every other
+      // host under the "openai" protocol (DeepSeek, vLLM, etc.) only serves
+      // /chat/completions, so route it through @ai-sdk/openai-compatible.
+      if (isRealOpenAIHost(baseUrl)) {
+        return {
+          npm: '@ai-sdk/openai',
+          options: {
+            ...apiKeyOption,
+            ...(baseUrl ? { baseURL: baseUrl } : {}),
+          },
+        };
+      }
       return {
-        npm: '@ai-sdk/openai',
+        npm: '@ai-sdk/openai-compatible',
         options: {
+          baseURL: baseUrl,
           ...apiKeyOption,
-          ...(baseUrl ? { baseURL: baseUrl } : {}),
         },
       };
     case 'senseaudio':

apps/daemon/tests/runtimes/byok-opencode.test.ts

@@ -74,6 +74,29 @@ describe('byok-opencode runtime config', () => {
     });
   });
 
+  it('routes OpenAI-protocol BYOK with a non-OpenAI base URL to the OpenAI-compatible provider package', () => {
+    expect(buildOpenCodeByokProviderConfig(
+      { protocol: 'openai', apiKey: 'sk-deepseek', baseUrl: 'https://api.deepseek.com' },
+      'deepseek-v4-pro',
+    )?.config).toMatchObject({
+      provider: {
+        [BYOK_OPENCODE_PROVIDER_ID]: {
+          npm: '@ai-sdk/openai-compatible',
+          options: {
+            baseURL: 'https://api.deepseek.com',
+            apiKey: `{env:${BYOK_OPENCODE_API_KEY_ENV}}`,
+          },
+        },
+      },
+    });
+    expect(buildOpenCodeByokProviderConfig(
+      { protocol: 'openai', apiKey: 'sk-openai', baseUrl: 'https://api.openai.com' },
+      'deepseek-v4-pro',
+    )?.config).toMatchObject({
+      provider: { [BYOK_OPENCODE_PROVIDER_ID]: { npm: '@ai-sdk/openai' } },
+    });
+  });
+
   it('normalizes origin-only native provider base URLs for OpenCode provider packages', () => {
     expect(buildOpenCodeByokProviderConfig(
       { protocol: 'anthropic', apiKey: 'sk-ant', baseUrl: 'https://api.anthropic.com' },
@@ -272,7 +295,7 @@ describe('byok-opencode runtime config', () => {
     expect(out?.config).toMatchObject({
       provider: {
         [BYOK_OPENCODE_PROVIDER_ID]: {
-          npm: '@ai-sdk/openai',
+          npm: '@ai-sdk/openai-compatible',
           options: {
             baseURL: 'http://127.0.0.1:8000/v1',
           },