[codex] Route opencode chat models through Zen (#638)

Co-authored-by: James Grugett <jahooma@gmail.com>

Author: brandonkachen

common/src/constants/model-config.ts

@@ -55,6 +55,7 @@ export type openrouterModel =
 
 export const openCodeZenModels = {
   opencode_kimi_k2_6: 'opencode/kimi-k2.6',
+  opencode_minimax_m2_7: 'opencode/minimax-m2.7',
 } as const
 export type OpenCodeZenModel =
   (typeof openCodeZenModels)[keyof typeof openCodeZenModels]

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

@@ -869,13 +869,24 @@ describe('/api/v1/chat/completions POST endpoint', () => {
     )
 
     it(
-      'routes OpenCode Zen models to the direct OpenCode Zen provider',
+      'routes OpenCode Zen-prefixed and Kimi models to the direct OpenCode Zen provider',
       async () => {
-        const expectedUpstreamModel: Record<string, string> = {
-          'opencode/kimi-k2.6': 'kimi-k2.6',
-        }
+        const testCases = [
+          {
+            codebuffModel: openCodeZenModels.opencode_kimi_k2_6,
+            upstreamModel: 'kimi-k2.6',
+          },
+          {
+            codebuffModel: openCodeZenModels.opencode_minimax_m2_7,
+            upstreamModel: 'minimax-m2.7',
+          },
+          {
+            codebuffModel: 'moonshotai/kimi-k2.6',
+            upstreamModel: 'kimi-k2.6',
+          },
+        ]
 
-        for (const codebuffModel of Object.values(openCodeZenModels)) {
+        for (const { codebuffModel, upstreamModel } of testCases) {
           const fetchedBodies: Record<string, unknown>[] = []
           const fetchedUrls: string[] = []
           const fetchViaOpenCodeZen = mock(
@@ -889,7 +900,7 @@ describe('/api/v1/chat/completions POST endpoint', () => {
               return new Response(
                 JSON.stringify({
                   id: 'test-id',
-                  model: expectedUpstreamModel[codebuffModel],
+                  model: upstreamModel,
                   choices: [{ message: { content: 'test response' } }],
                   usage: {
                     prompt_tokens: 10,
@@ -968,16 +979,67 @@ describe('/api/v1/chat/completions POST endpoint', () => {
           expect(fetchedUrls[0]).toBe(
             'https://opencode.ai/zen/v1/chat/completions',
           )
-          expect(fetchedBodies[0].model).toBe(
-            expectedUpstreamModel[codebuffModel],
-          )
+          expect(fetchedBodies[0].model).toBe(upstreamModel)
           expect(body.model).toBe(codebuffModel)
           expect(body.provider).toBe('OpenCode Zen')
         }
       },
       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

@@ -34,34 +34,56 @@ interface OpenCodeZenPricing {
   outputCostPerToken: number
 }
 
-const OPENCODE_ZEN_MODELS: Record<
-  string,
-  { opencodeId: string; pricing: OpenCodeZenPricing }
-> = {
-  [openCodeZenModels.opencode_kimi_k2_6]: {
-    opencodeId: 'kimi-k2.6',
-    pricing: {
-      inputCostPerToken: 0.95 / 1_000_000,
-      cachedInputCostPerToken: 0.16 / 1_000_000,
-      outputCostPerToken: 4.0 / 1_000_000,
-    },
+const OPENCODE_MODEL_PREFIX = 'opencode/'
+const MOONSHOT_KIMI_MODEL = 'moonshotai/kimi-k2.6'
+const KIMI_ZEN_MODEL = 'kimi-k2.6'
+const MINIMAX_M2_7_ZEN_MODEL = 'minimax-m2.7'
+
+const OPENCODE_ZEN_MODEL_ALIASES: Record<string, string> = {
+  [openCodeZenModels.opencode_kimi_k2_6]: KIMI_ZEN_MODEL,
+  [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,
+  cachedInputCostPerToken: 0.16 / 1_000_000,
+  outputCostPerToken: 4.0 / 1_000_000,
+}
+
+const OPENCODE_ZEN_PRICING: Record<string, OpenCodeZenPricing> = {
+  [KIMI_ZEN_MODEL]: KIMI_ZEN_PRICING,
+  [MINIMAX_M2_7_ZEN_MODEL]: {
+    inputCostPerToken: 0.3 / 1_000_000,
+    cachedInputCostPerToken: 0.06 / 1_000_000,
+    outputCostPerToken: 1.2 / 1_000_000,
   },
 }
 
-export function isOpenCodeZenModel(model: string): boolean {
-  return model in OPENCODE_ZEN_MODELS
+export function isOpenCodeZenModel(model: unknown): model is string {
+  if (typeof model !== 'string') return false
+  return (
+    model.startsWith(OPENCODE_MODEL_PREFIX) ||
+    model in OPENCODE_ZEN_MODEL_ALIASES
+  )
 }
 
 function getOpenCodeZenModelId(model: string): string {
-  return OPENCODE_ZEN_MODELS[model]?.opencodeId ?? 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 {
-  const entry = OPENCODE_ZEN_MODELS[model]
-  if (!entry) {
-    throw new Error(`No OpenCode Zen pricing found for model: ${model}`)
-  }
-  return entry.pricing
+  return OPENCODE_ZEN_PRICING[getOpenCodeZenModelId(model)] ?? KIMI_ZEN_PRICING
 }
 
 type StreamState = {