Reject unsupported opencode Zen models

Author: jahooma

web/src/app/api/v1/chat/completions/__tests__/completions.test.ts

@@ -880,10 +880,6 @@ describe('/api/v1/chat/completions POST endpoint', () => {
             codebuffModel: openCodeZenModels.opencode_minimax_m2_7,
             upstreamModel: 'minimax-m2.7',
           },
-          {
-            codebuffModel: 'opencode/qwen3-coder',
-            upstreamModel: 'qwen3-coder',
-          },
           {
             codebuffModel: 'moonshotai/kimi-k2.6',
             upstreamModel: 'kimi-k2.6',
@@ -991,6 +987,59 @@ describe('/api/v1/chat/completions POST endpoint', () => {
       FETCH_PATH_TEST_TIMEOUT_MS,
     )
 
+    it(
+      'rejects unsupported OpenCode Zen-prefixed models without calling the provider',
+      async () => {
+        const fetchViaOpenCodeZen = mock(
+          async (url: string | URL | Request) => {
+            if (String(url).startsWith('https://api.ipinfo.io/lookup/')) {
+              return Response.json({})
+            }
+
+            throw new Error('OpenCode Zen provider should not be called')
+          },
+        ) as unknown as typeof globalThis.fetch
+
+        const req = new NextRequest(
+          'http://localhost:3000/api/v1/chat/completions',
+          {
+            method: 'POST',
+            headers: {
+              Authorization: 'Bearer test-api-key-123',
+            },
+            body: JSON.stringify({
+              model: 'opencode/qwen3-coder',
+              messages: [{ role: 'user', content: 'hello' }],
+              stream: false,
+              codebuff_metadata: {
+                run_id: 'run-123',
+                client_id: 'test-client-id-123',
+              },
+            }),
+          },
+        )
+
+        const response = await postChatCompletions({
+          req,
+          getUserInfoFromApiKey: mockGetUserInfoFromApiKey,
+          logger: mockLogger,
+          trackEvent: mockTrackEvent,
+          getUserUsageData: mockGetUserUsageData,
+          getAgentRunFromId: mockGetAgentRunFromId,
+          fetch: fetchViaOpenCodeZen,
+          insertMessageBigquery: mockInsertMessageBigquery,
+          loggerWithContext: mockLoggerWithContext,
+        })
+
+        const body = await response.json()
+        expect(response.status).toBe(400)
+        expect(body.error.code).toBe('unsupported_model')
+        expect(body.error.message).toContain('opencode/qwen3-coder')
+        expect(fetchViaOpenCodeZen).toHaveBeenCalledTimes(0)
+      },
+      FETCH_PATH_TEST_TIMEOUT_MS,
+    )
+
     it('rejects the DeepSeek V4 free agent when it requests another free model', async () => {
       const req = new NextRequest(
         'http://localhost:3000/api/v1/chat/completions',

web/src/llm-api/opencode-zen.ts

@@ -44,6 +44,7 @@ const OPENCODE_ZEN_MODEL_ALIASES: Record<string, string> = {
   [openCodeZenModels.opencode_minimax_m2_7]: MINIMAX_M2_7_ZEN_MODEL,
   [MOONSHOT_KIMI_MODEL]: KIMI_ZEN_MODEL,
 }
+const SUPPORTED_OPENCODE_ZEN_MODELS = Object.keys(OPENCODE_ZEN_MODEL_ALIASES)
 
 const KIMI_ZEN_PRICING: OpenCodeZenPricing = {
   inputCostPerToken: 0.95 / 1_000_000,
@@ -69,12 +70,16 @@ export function isOpenCodeZenModel(model: unknown): model is string {
 }
 
 function getOpenCodeZenModelId(model: string): string {
-  return (
-    OPENCODE_ZEN_MODEL_ALIASES[model] ??
-    (model.startsWith(OPENCODE_MODEL_PREFIX)
-      ? model.slice(OPENCODE_MODEL_PREFIX.length)
-      : model)
-  )
+  const opencodeId = OPENCODE_ZEN_MODEL_ALIASES[model]
+  if (opencodeId) return opencodeId
+
+  throw new OpenCodeZenError(400, 'Bad Request', {
+    error: {
+      message: `Unsupported OpenCode Zen model: ${model}. Supported models: ${SUPPORTED_OPENCODE_ZEN_MODELS.join(', ')}`,
+      code: 'unsupported_model',
+      type: 'invalid_request_error',
+    },
+  })
 }
 
 function getOpenCodeZenPricing(model: string): OpenCodeZenPricing {