OpenAI SDK - to11

This guide shows you how to point the official OpenAI SDK at the to11 gateway. Set the base_url to the gateway, authenticate to to11 with the x-to11-authorization header, keep passing your provider key as the SDK’s api_key, and name the provider in the model string — openai::gpt-4o, where openai is the routing identifier of your OpenAI provider in to11. See Naming the provider in a request. The rest of your code stays the same.

Python

Install the SDK if you haven’t already:

pip install openai

Set the base_url to your gateway:

from openai import OpenAI

client = OpenAI(
    base_url="https://gw.to11.ai/v1",
    api_key="<your OpenAI API key>",  # provider credential, forwarded upstream
    default_headers={
        "x-to11-authorization": "Bearer <your to11 API key>",  # to11 auth — Settings → API keys
        "x-to11-project-id": "<your project id>",
    },
)

response = client.chat.completions.create(
    model="openai::gpt-4o",
    messages=[{"role": "user", "content": "Hello from to11!"}],
    max_tokens=256,
)
print(response.choices[0].message.content)

TypeScript / Node.js

npm install openai

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://gw.to11.ai/v1",
  apiKey: "<your OpenAI API key>", // provider credential, forwarded upstream
  defaultHeaders: {
    "x-to11-authorization": "Bearer <your to11 API key>", // to11 auth — Settings → API keys
    "x-to11-project-id": "<your project id>",
  },
});

const response = await client.chat.completions.create({
  model: "openai::gpt-4o",
  messages: [{ role: "user", content: "Hello from to11!" }],
  max_tokens: 256,
});
console.log(response.choices[0].message.content);

Streaming

Add stream: true to receive the response incrementally. The gateway streams chunks back as they arrive from the provider, and the call is traced the same as a non-streaming one.

stream = client.chat.completions.create(
    model="openai::gpt-4o",
    messages=[{"role": "user", "content": "Count to 10"}],
    stream=True,
)
for chunk in stream:
    # The usage chunk at the end of the stream has an empty `choices` list.
    if chunk.choices and chunk.choices[0].delta.content:
        print(chunk.choices[0].delta.content, end="", flush=True)

const stream = await client.chat.completions.create({
  model: "openai::gpt-4o",
  messages: [{ role: "user", content: "Count to 10" }],
  stream: true,
});
for await (const chunk of stream) {
  const content = chunk.choices[0]?.delta?.content;
  if (content) process.stdout.write(content);
}

Providers the OpenAI SDK reaches

The gateway forwards your request to the provider as you wrote it and does not convert between wire formats. The OpenAI SDK therefore reaches only providers that speak the OpenAI format:

client.chat.completions (/v1/chat/completions) — OpenAI, xAI, and the OpenAI-compatible providers, including Google Gemini, Google Vertex AI, and Cohere through their OpenAI-compatible endpoints.
client.responses (/v1/responses) — OpenAI and xAI.

To call an Anthropic model, use the Anthropic SDK. A request from the OpenAI SDK that names an Anthropic provider, such as anthropic::claude-sonnet-4-6, is rejected with 400 Bad Request and the x-to11-error-code: cross_dialect header before anything is sent to the provider. See Which SDK to call a provider with.

Tool calling

Tool calling works identically to direct OpenAI usage:

response = client.chat.completions.create(
    model="openai::gpt-4o",
    messages=[{"role": "user", "content": "What's the weather in Paris?"}],
    tools=[{
        "type": "function",
        "function": {
            "name": "get_weather",
            "description": "Get current weather for a location",
            "parameters": {
                "type": "object",
                "properties": {
                    "location": {"type": "string"}
                },
                "required": ["location"],
            },
        },
    }],
)

The tools array reaches the provider unchanged.

Environment variable configuration

If you prefer not to hard-code the base URL, use the OPENAI_BASE_URL environment variable:

export OPENAI_BASE_URL=https://gw.to11.ai/v1

# No base_url needed — the SDK reads OPENAI_BASE_URL. Still pass the to11 auth header.
client = OpenAI(
    api_key="<your OpenAI API key>",
    default_headers={"x-to11-authorization": "Bearer <your to11 API key>"},
)

​Python

​TypeScript / Node.js

​Streaming

​Providers the OpenAI SDK reaches

​Tool calling

​Environment variable configuration