xAI: Grok 3 Mini Beta · fastrouter

Grok 3 Mini Beta is xAI's lightweight reasoning model designed specifically for quantitative problem-solving with transparent thinking processes. Unlike conventional AI systems that generate immediate answers, this model implements explicit reasoning steps before responding, making it particularly effective for mathematics, puzzles, and logical reasoning tasks. The model defaults to low reasoning effort but can be configured with increased reasoning capacity (reasoning: { effort: high }) for more complex problems. With accessible thinking traces, users can examine the model's step-by-step problem-solving approach, providing valuable insights into its reasoning process. This beta release offers early access to xAI's reasoning capabilities through dual endpoint options: a standard endpoint optimized for quality and a fast endpoint prioritizing throughput for latency-sensitive applications.

Base model All models on this base All models of the provider to the provider

Input, $/1M $0.60

Output, $/1M $4.00

Cache read $0.15

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Last checked 04.11.2026 12:00:14 UTC

Source provider's page

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API

OpenAI-compatible API: the official OpenAI SDKs work with this base URL. Replace YOUR_API_KEY with your key from the provider.

API base URL	`https://go.fastrouter.ai/api/v1`
Endpoint	`https://go.fastrouter.ai/api/v1/chat/completions`
Model id	`x-ai/grok-3-mini-beta`

curl

curl https://go.fastrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "x-ai/grok-3-mini-beta", "messages": [{"role": "user", "content": "Hello!"}], "max_tokens": 256}'

Python

import requests

r = requests.post(
    "https://go.fastrouter.ai/api/v1/chat/completions",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={
      "model": "x-ai/grok-3-mini-beta",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ],
      "max_tokens": 256
    },
)
print(r.json())

JavaScript

const r = await fetch("https://go.fastrouter.ai/api/v1/chat/completions", {
  method: "POST",
  headers: {Authorization: "Bearer YOUR_API_KEY", "Content-Type": "application/json"},
  body: JSON.stringify({
    "model": "x-ai/grok-3-mini-beta",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ],
    "max_tokens": 256
  }),
});
console.log(await r.json());

Request (JSON)

{
  "model": "x-ai/grok-3-mini-beta",
  "messages": [
    {
      "role": "user",
      "content": "Hello!"
    }
  ],
  "max_tokens": 256
}

Response (JSON)

{
  "id": "chatcmpl-...",
  "object": "chat.completion",
  "model": "x-ai/grok-3-mini-beta",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hi! How can I help?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 9,
    "completion_tokens": 12,
    "total_tokens": 21
  }
}

The address is taken from the provider's model list; check it against the provider's documentation.

Provider's API documentation

Source: AI Rate Card, https://airatecard.com/en/c/offer%3Afastrouter%7Cx-ai/grok-3-mini-beta, prices checked 2026-11-04; seller's page: https://fastrouter.ai/models/x-ai/grok-3-mini-beta

Technical details

ID: offer:fastrouter|x-ai/grok-3-mini-beta