Grok 4.1 Fast (Reasoning) API
About
Build advanced reasoning agents with Grok 4.1 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 4.1 Fast (Reasoning) via the Firmware API with up to 128K 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
128K
Tokens
Pricing
Standard (per 1M tokens)
Input
$0.20
Output
$0.50
Caching (per 1M tokens)
Read
$0.05
Frequently Asked Questions
Grok 4.1 Fast (Reasoning) by Firmware 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-4-1-fast-reasoning
Provider
FirmwareFamily
grok
Release Date
Nov 25, 2025
Knowledge Cutoff
Nov 1, 2025
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
FIRMWARE_API_KEY
API Base URL
https://app.frogbot.ai/api/v1