Grok 4 Fast Reasoning

Chat Completions

grok-4-fast-reasoning

xAI|Created Sep 20, 2025|2M context

Chat Completions

State-of-the-art reasoning model optimized for cost-efficient, high-quality chain-of-thought. Trained end-to-end with tool use and agentic search, it matches top-tier benchmarks like AIME, HMMT, and GPQA at 40% lower token use versus Grok 4. Features a huge 2M token context and native web/X browsing. Ideal for agentic workflows, research, code, logic, and complex multi-step tasks. Offers up to 98% cheaper reasoning versus previous models.

Overview Specifications Activity Performance Uptime Examples

Pricing-50%

Pay-as-you-go rates for this model. More details can be found here.

Input Tokens (1M)

$0.10

Cached Input Tokens (1M)

$0.02

Output Tokens (1M)

$0.25

Capabilities

Input Modalities

TextImage

Output Modalities

Text

Supported Parameters

Available parameters for API requests

Max Completion TokensResponse FormatTemperatureTool ChoiceToolsTop PWeb Search Options

Usage Analytics

Token usage of this model on our platform

Throughput

Time-To-First-Token (TTFT)

Code Example

Example code for using this model through our API with Python (OpenAI SDK) or cURL. Replace placeholders with your API key and model ID.

Basic request example. Ensure API key permissions. For more details, see our documentation.

from openai import OpenAI

client = OpenAI(
    base_url="https://api.naga.ac/v1",
    api_key="YOUR_API_KEY",
)

resp = client.chat.completions.create(
    model="grok-4-fast-reasoning",
    messages=[
        {"role": "user", "content": "What's 2+2?"}
    ],
    temperature=0.2,
)
print(resp.choices[0].message.content)