Protocols

OpenAI-compatible API

If your code already talks to the OpenAI API, it already talks to RelayRouter. Point the client at https://relayrouter.io/v1, use a RelayRouter key as the API key, and send the same request bodies you send today. The gateway accepts the OpenAI request shape, routes it to the group your key belongs to and returns the OpenAI response shape, including server-sent events for streaming.

Base URL and endpoints

https://relayrouter.io/v1 Set this as the base URL of any OpenAI client; the SDK appends the endpoint paths itself.

Authentication: Authorization: Bearer <your RelayRouter key>. The key decides the group, and the group decides which models and which rate apply.

Code

from openai import OpenAI

client = OpenAI(
    api_key="your-relayrouter-key",
    base_url="https://relayrouter.io/v1",  # the only change
)

res = client.chat.completions.create(
    model="gpt-6-astra",
    messages=[{"role": "user", "content": "Hello!"}],
    stream=False,
)
print(res.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.RELAYROUTER_API_KEY,
  baseURL: "https://relayrouter.io/v1",
});

const stream = await client.chat.completions.create({
  model: "gpt-6-astra",
  messages: [{ role: "user", content: "Hello!" }],
  stream: true,
});
for await (const chunk of stream) process.stdout.write(chunk.choices[0]?.delta?.content ?? "");

curl https://relayrouter.io/v1/chat/completions \
  -H "Authorization: Bearer $RELAYROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-6-astra", "messages": [{"role": "user", "content": "Hello!"}]}'

Groups that speak this protocol

A key belongs to one group. Create it in the console for one of the groups below; the models page has every group and model with live rates.

Tools that work as-is

• OpenAI SDK (Python, TypeScript, .NET, Java, Go): set base_url and api_key
• LangChain ChatOpenAI: openai_api_base=https://relayrouter.io/v1 (guide)
• LiteLLM: model=openai/<id>, api_base=https://relayrouter.io/v1
• Cursor: Override OpenAI Base URL (guide)
• Cline / Roo Code: OpenAI Compatible provider (guide)
• Dify: OpenAI-API-compatible model provider (guide)

Questions