Grok 4 Fast Reasoning API
About
Build advanced reasoning agents with Grok 4 Fast Reasoning, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers cost-effective pricing at $0.20/1M input and $0.50/1M output tokens, native tool calling support. Access Grok 4 Fast Reasoning via the DevPass (LLM Gateway) API with up to 30K output tokens.
Capabilities
Input Modalities
textimage
Output Modalities
text
Reasoning
Yes
Structured Output
Limits
Context Window
2.0M
Tokens
Input Limit
2.0M
Tokens
Max Output
30K
Tokens
Pricing
Standard (per 1M tokens)
Input
$0.20
Output
$0.50
Caching (per 1M tokens)
Read
$0.05
Frequently Asked Questions
Grok 4 Fast Reasoning by DevPass (LLM Gateway) costs $0.20 per 1M input tokens and $0.50 per 1M output tokens. Cached reads cost $0.05 per 1M tokens.
Model Details
ID
grok-4-fast-reasoning
Provider
DevPass (LLM Gateway)Family
grok
Release Date
Jul 9, 2025
Knowledge Cutoff
N/A
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
LLMGATEWAY_API_KEY
API Base URL
https://api.llmgateway.io/v1