Gemini 3.1 Pro Preview API
About
Build advanced reasoning agents with Gemini 3.1 Pro Preview, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers cost-effective pricing at $2.00/1M input and $12.00/1M output tokens, native tool calling support. Access Gemini 3.1 Pro Preview via the FastRouter API with up to 66K output tokens.
Capabilities
Input Modalities
textimagevideoaudio
Limits
Context Window
1.0M
Tokens
Input Limit
1.0M
Tokens
Max Output
66K
Tokens
Pricing
Standard (per 1M tokens)
Input
$2.00
Output
$12.00
Frequently Asked Questions
Gemini 3.1 Pro Preview by FastRouter costs $2.00 per 1M input tokens and $12.00 per 1M output tokens.
Model Details
ID
google/gemini-3.1-pro-preview
Provider
FastRouterFamily
gemini-pro
Release Date
Feb 19, 2026
Knowledge Cutoff
Jan 1, 2025
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
FASTROUTER_API_KEY
API Base URL
https://go.fastrouter.ai/api/v1