maybe fix

src/proxy.js

@@ -128,6 +128,20 @@ function validateContext(body, maxContextTokens) {
   }
 }
 
+function normalizeChatCompletionRequest(body) {
+  if (!body || typeof body !== 'object' || Array.isArray(body) || body.max_completion_tokens === undefined) {
+    return body;
+  }
+
+  // OpenAI renamed max_tokens to max_completion_tokens, but OpenCode Go's
+  // OpenAI-compatible providers do not all accept the newer field. Normalize
+  // it at the provider boundary so the same client request works across
+  // models. If a client supplied both names, keep the explicit legacy value.
+  const { max_completion_tokens: maxCompletionTokens, ...normalized } = body;
+  if (normalized.max_tokens === undefined) normalized.max_tokens = maxCompletionTokens;
+  return normalized;
+}
+
 function withContextLimit(payload, maxContextTokens, allowedModels) {
   return {
     ...payload,
@@ -252,10 +266,11 @@ export function createProxyApp({ keys, keyRotator = createKeyRotator(keys), fetc
 
   app.post('/oai/v1/chat/completions', async (request, response) => {
     try {
-      validateContext(request.body, maxContextTokens);
+      const upstreamBody = normalizeChatCompletionRequest(request.body);
+      validateContext(upstreamBody, maxContextTokens);
       const ip = clientIp(request);
       const unlimited = hasUnlimitedKey(request, unlimitedKeys);
-      if (!unlimited) validateAllowedModel(request.body?.model, allowedModels);
+      if (!unlimited) validateAllowedModel(upstreamBody?.model, allowedModels);
       if (!unlimited) {
         const limit = await rateLimiter.check(ip);
         if (!limit.allowed) return rateLimitError(response, false, limit);
@@ -264,15 +279,15 @@ export function createProxyApp({ keys, keyRotator = createKeyRotator(keys), fetc
         method: 'POST',
         headers: {
           'content-type': 'application/json',
-          accept: request.body?.stream ? 'text/event-stream' : 'application/json',
+          accept: upstreamBody?.stream ? 'text/event-stream' : 'application/json',
         },
-        body: JSON.stringify(request.body),
+        body: JSON.stringify(upstreamBody),
       });
 
       if (!upstream.ok) return forwardError(upstream, response);
       copyResponseHeaders(upstream, response);
 
-      if (request.body?.stream && upstream.body) {
+      if (upstreamBody?.stream && upstream.body) {
         response.status(upstream.status);
         let streamBuffer = '';
         let recordedCost = false;

test/proxy.test.js

@@ -69,12 +69,39 @@ describe('proxy', () => {
     expect(JSON.parse(fetchImpl.mock.calls[0][1].body)).toEqual(body);
   });
 
+  it('normalizes max_completion_tokens for OpenCode Go providers', async () => {
+    const fetchImpl = vi.fn().mockResolvedValue(response('{"id":"completion-1"}'));
+    const app = createProxyApp({ keys: ['key'], fetchImpl });
+
+    await request(app).post('/oai/v1/chat/completions').send({
+      model: 'kimi-k3', messages: [{ role: 'user', content: 'Hi' }],
+      max_completion_tokens: 4096, stream: true, stream_options: { include_usage: true },
+    }).expect(200);
+
+    expect(JSON.parse(fetchImpl.mock.calls[0][1].body)).toEqual({
+      model: 'kimi-k3', messages: [{ role: 'user', content: 'Hi' }],
+      max_tokens: 4096, stream: true, stream_options: { include_usage: true },
+    });
+  });
+
+  it('prefers max_tokens when both token limit field names are supplied', async () => {
+    const fetchImpl = vi.fn().mockResolvedValue(response('{"id":"completion-1"}'));
+    const app = createProxyApp({ keys: ['key'], fetchImpl });
+
+    await request(app).post('/oai/v1/chat/completions').send({
+      model: 'm', max_tokens: 2048, max_completion_tokens: 4096,
+    }).expect(200);
+
+    expect(JSON.parse(fetchImpl.mock.calls[0][1].body)).toEqual({ model: 'm', max_tokens: 2048 });
+  });
+
   it('enforces the configured context and IP limits and records cost', async () => {
     const fetchImpl = vi.fn()
       .mockResolvedValueOnce(response(JSON.stringify({ id: 'c', cost: 0 })))
       .mockResolvedValue(response(JSON.stringify({ id: 'c', cost: 10 })));
     const app = createProxyApp({ keys: ['key'], fetchImpl, maxContextTokens: 100 });
     await request(app).post('/oai/v1/chat/completions').set('X-Real-IP', '198.51.100.1').send({ model: 'm', max_tokens: 101 }).expect(400);
+    await request(app).post('/oai/v1/chat/completions').set('X-Real-IP', '198.51.100.1').send({ model: 'm', max_completion_tokens: 101 }).expect(400);
     await request(app).post('/oai/v1/chat/completions').set('X-Real-IP', '198.51.100.1').send({ model: 'm', max_tokens: 1 }).expect(200);
     await request(app).post('/oai/v1/chat/completions').set('X-Real-IP', '198.51.100.1').send({ model: 'm', max_tokens: 1 }).expect(200);
     await request(app).post('/oai/v1/chat/completions').set('X-Real-IP', '198.51.100.1').send({ model: 'm', max_tokens: 1 }).expect(429);