JavaScript

Install

npm i openai

Configure

Point the client at https://api.routeur.ai/v1 and pass your routeur.ai key as the API key:

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.routeur.ai/v1",
  apiKey:  process.env.ROUTEUR_KEY,
});

Example

const res = await client.chat.completions.create({
  model: "auto",
  messages: [{ role: "user", content: "Say hello in one short sentence." }],
});

console.log(res.choices[0].message.content);
// Inspect routing metadata:
console.log(res.routeur.ai);

Streaming

Streaming works exactly as it does against OpenAI:

const stream = await client.chat.completions.create({
  model:    "auto",
  stream:   true,
  messages: [{ role: "user", content: "Stream a haiku." }],
});

for await (const chunk of stream) {
  process.stdout.write(chunk.choices[0]?.delta?.content ?? "");
}

Choosing a model

Every request picks an upstream model in one of three ways — in this order of precedence:

1. Routeur-* request headers. If Routeur-Provider or Routeur-Model are set, they win, regardless of what is in the body. Useful from middleware or transports that can't change the JSON.
2. An explicit upstream id in model. Pass something like "gpt-4o-mini" or "claude-3-5-sonnet" to bypass routing rules and pin the request to that model.
3. model: "auto" (or any alias). Lets routeur.ai pick the upstream model from your routing rules. This is the recommended default.

Force a specific provider+model on a single call via headers (the body's model is ignored when headers are set):

await client.chat.completions.create(
  { model: "auto", messages },
  { headers: { "Routeur-Provider": "openai", "Routeur-Model": "gpt-4o" } }
);