Overview
The LLM Gateway is one OpenAI-compatible API for every model on Clusterbase — OpenAI, Anthropic, and open-weight models behind a single key.
The LLM Gateway gives you every model on Clusterbase through one API and one key. The surface is OpenAI-compatible, so existing OpenAI SDKs work unchanged — point them at the gateway's base URL and swap the model ID.
https://llm.clusterbase.devAuthentication is a bearer token on every request. Use an
organization API key (ccp_live_ak_…), created in
the Console.
Jump straight in
curl https://llm.clusterbase.dev/v1/chat/completions \
-H "Authorization: Bearer $CLUSTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "claude-opus-5",
"messages": [
{ "role": "user", "content": "Fix this function and explain the bug: function median(a){a.sort();return a[a.length/2]}" }
]
}'Use the OpenAI SDK with the gateway's base URL:
import OpenAI from 'openai';
const client = new OpenAI({
apiKey: process.env.CLUSTER_API_KEY,
baseURL: 'https://llm.clusterbase.dev/v1',
});
const response = await client.chat.completions.create({
model: 'claude-opus-5',
messages: [{ role: 'user', content: 'Say hi.' }],
});
console.log(response.choices[0].message.content);Use the OpenAI SDK with the gateway's base URL:
import os
from openai import OpenAI
client = OpenAI(
api_key=os.environ["CLUSTER_API_KEY"],
base_url="https://llm.clusterbase.dev/v1",
)
response = client.chat.completions.create(
model="claude-opus-5",
messages=[{"role": "user", "content": "Say hi."}],
)
print(response.choices[0].message.content)Use the Vercel AI SDK through its OpenAI-compatible provider:
import { createOpenAICompatible } from '@ai-sdk/openai-compatible';
import { generateText } from 'ai';
const clusterbase = createOpenAICompatible({
name: 'clusterbase',
baseURL: 'https://llm.clusterbase.dev/v1',
apiKey: process.env.CLUSTER_API_KEY,
});
const { text } = await generateText({
model: clusterbase('claude-opus-5'),
prompt: 'Say hi.',
});
console.log(text);The gateway also speaks the AI SDK's UI Message Stream natively — see Vercel AI SDK.
Streaming
Set "stream": true on /v1/chat/completions to receive Server-Sent Events,
terminated by data: [DONE]. Add "stream_options": {"include_usage": true}
to receive a final chunk with token usage.
curl -N https://llm.clusterbase.dev/v1/chat/completions \
-H "Authorization: Bearer $CLUSTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-5.6",
"stream": true,
"stream_options": { "include_usage": true },
"messages": [{ "role": "user", "content": "Say hi." }]
}'Tool calling and reasoning output are available on streaming requests. A non-streaming response returns text only.
Endpoints
| Endpoint | Description |
|---|---|
POST /v1/chat/completions | OpenAI-compatible chat completions, with optional SSE streaming |
POST /v1/chat | Vercel AI SDK UI Message Stream (streaming only) |
GET /v1/models | Model catalog with context windows and pricing |
The full request and response schemas are in the LLM Gateway API reference.
Next steps
- Create an API key in the Console.
- Browse models and pricing.
- Build a chat UI with the Vercel AI SDK.