Make your first API request

A request traveling from application code through an API gateway to a language model

npm install openai

Create a server-side file such as example.mjs. Keep the API key in an environment variable; do not expose it in browser JavaScript.

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://inference-api.openserv.ai/v1",
  apiKey: process.env.SERV_API_KEY,
});

const response = await client.chat.completions.create({
  model: "gpt-5.4-mini",
  reasoning_effort: "low",
  messages: [
    { role: "system", content: "You classify support requests." },
    { role: "user", content: "I was charged twice for the same order." },
  ],
});

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

Every request must include a system prompt, developer message, or instructions field. Browse the model catalog for supported model IDs. The response uses the standard Chat Completions shape. The generated text is in choices[0].message.content, and usage data is in response.usage. If the request fails, check the API key, organization balance, model ID, and system prompt first. For endpoint-specific fields, see the Chat Completions reference.

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Make your first API request