Working with messages (TypeScript)

Chat Completions returns choices containing assistant messages. Check the response before reading the first choice, especially when handling tool calls or empty output.

This guide uses the official OpenAI client with TheRouter; it is not a TheRouter-owned SDK. The therouter and @therouter/sdk packages previously named here are not currently published in the public package registries.

npm install openai

import OpenAI from "openai";

const client = new OpenAI({ apiKey: process.env.THEROUTER_API_KEY, baseURL: "https://api.therouter.ai/v1" });
const completion = await client.chat.completions.create({
  model: "openai/gpt-4o-mini",
  messages: [{ role: "user", content: "Hello!" }],
  max_tokens: 32,
});
console.log(completion.choices[0]?.message.content);