Grok 4.1 Fast is xAI's best agentic tool calling model that shines in real-world use cases like customer support and deep research. 2M context window. Reasoning can be enabled/disabled using the `reasoning` `enabled` parameter in the API

Pricing

Price per input token: $0.0000002

Price per output token: $0.0000005

Usage Example

NOTE: BrainLink is compatible with the OpenAI API, which allows you to use the OpenAI SDK even with non-OpenAI models

import OpenAI from "openai";
const userAccessToken = await BrainLink.getUserToken();
const openai = new OpenAI({
    baseURL: "https://www.brainlink.dev/api/v1",
    apiKey: userAccessToken,
});
const completion = await openai.chat.completions.create({
    model: "x-ai/grok-4.1-fast",
    messages: [
      { role: "user", content: "Hi! How are you today?" }
    ],
});