Grok 4.5

Using the API

If you already have an API key, set the model name to grok-4.5:

import os
from xai_sdk import Client
from xai_sdk.chat import user

client = Client(api_key=os.getenv("XAI_API_KEY"))

chat = client.chat.create(model="grok-4.5")
chat.append(user("Find and fix the bug, then explain it: function median(a){a.sort();return a[a.length/2]}"))

response = chat.sample()
print(response.content)

import { xai } from '@ai-sdk/xai';
import { generateText } from 'ai';

const { text } = await generateText({
  model: xai.responses('grok-4.5'),
  prompt:
    'Find and fix the bug, then explain it: function median(a){a.sort();return a[a.length/2]}',
});

console.log(text);

import OpenAI from 'openai';

const client = new OpenAI({
  apiKey: process.env.XAI_API_KEY,
  baseURL: 'https://api.x.ai/v1',
});

const response = await client.responses.create({
  model: 'grok-4.5',
  input: [
    {
      role: 'user',
      content:
        'Find and fix the bug, then explain it: function median(a){a.sort();return a[a.length/2]}',
    },
  ],
});

console.log(response.output_text);

curl https://api.x.ai/v1/responses \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $XAI_API_KEY" \
  -d '{
    "model": "grok-4.5",
    "input": "Find and fix the bug, then explain it: function median(a){a.sort();return a[a.length/2]}"
  }'

New to the xAI API? Follow the Quickstart to create an account and make your first request.

At a glance

Full context window, rate limits, and live pricing for your team are on the model detail page and Pricing.

For benchmark results and cost-versus-score comparisons, see the announcement.

Important details

• We highly recommend setting a prompt_cache_key (Responses API; x-grok-conv-id header on Chat Completions). It routes a conversation's requests to the same server, making cache hits reliable; without it you often pay full input price on a cache-cold server. See What Breaks Caching for common mistakes.

• Long agent loops additionally benefit from context compaction; for tool-heavy workloads see function calling.

Where it runs

• xAI API: get a key from the console

• Grok Build: the default model of the coding agent, on the API and CLI

• Cursor: available on all plans

• Office add-ins: default model in the Word, PowerPoint, and Excel add-ins

• Model gateways: OpenRouter, Vercel, Cloudflare, Snowflake, and Databricks Mosaic

Learn more

• Reasoning - controlling reasoning_effort

• Announcement - launch post with demos and full benchmark figures

• Models - compare available models and their capabilities

• Pricing - token pricing for all models