Migrate from OpenAI

FluxRouter speaks the OpenAI API. If your code already calls OpenAI, you keep the same SDK and the same request shape. You change three things:

1. Base URL to https://api.fluxrouter.ai/v1
2. API key to your Flux key (sk-... from the dashboard)
3. Model to flux-auto (or a specific flux-* id)

That's the whole migration. The endpoints (/chat/completions, /responses, /models), the request and response JSON, streaming, tools, and structured outputs all stay the same.

Get a Flux key#

Sign up at /auth/sign-up, open the dashboard, and create an API key. It looks like sk-.... The examples below read it from a FLUX_API_KEY environment variable.

Migrate the Python SDK#

Before (OpenAI)#

from openai import OpenAI

client = OpenAI(
    api_key="sk-openai-...",
)

response = client.chat.completions.create(
    model="gpt-4o",
    messages=[{"role": "user", "content": "Say hello."}],
)

print(response.choices[0].message.content)

After (FluxRouter)#

from openai import OpenAI

client = OpenAI(
    api_key="sk-...",                          # your Flux key
    base_url="https://api.fluxrouter.ai/v1",   # the one line you change
)

response = client.chat.completions.create(
    model="flux-auto",                         # let Flux route, or pin a flux-* id
    messages=[{"role": "user", "content": "Say hello."}],
)

print(response.choices[0].message.content)

Migrate the Node SDK#

Before (OpenAI)#

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.OPENAI_API_KEY,
});

const response = await client.chat.completions.create({
  model: "gpt-4o",
  messages: [{ role: "user", content: "Say hello." }],
});

console.log(response.choices[0].message.content);

After (FluxRouter)#

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.FLUX_API_KEY,            // your Flux key
  baseURL: "https://api.fluxrouter.ai/v1",     // the one line you change
});

const response = await client.chat.completions.create({
  model: "flux-auto",                          // let Flux route, or pin a flux-* id
  messages: [{ role: "user", content: "Say hello." }],
});

console.log(response.choices[0].message.content);

What stays the same#

Everything except the three values above:

• The OpenAI SDK and its method names (chat.completions.create, responses.create).
• The endpoints: /v1/chat/completions, /v1/responses, /v1/models.
• Auth header style: Authorization: Bearer sk-....
• The request and response JSON, including streaming (stream: true), tool calls, and structured outputs.
• Your prompts, message arrays, and parameters like temperature and max_tokens.

What to do about the model field#

OpenAI model ids like gpt-4o are not Flux models. Pick one of these instead:

• flux-auto (recommended): Flux routes each request to a sensible model for the prompt. Use this and you don't have to choose.
• A tier alias (flux-fast, flux-standard, flux-reasoning, flux-image) or a flux-pinned-* id when you want the same backing model every time.

The authoritative list of model ids is GET https://api.fluxrouter.ai/v1/models. See Models for what each alias means.

Next steps#

• Models: every model alias and how flux-auto and pinning work.
• Connect your tools: point an AI coding tool at Flux instead of code.