Google: Gemini 3.1 Pro Preview Custom Tools API
About
Build advanced reasoning agents with Google: Gemini 3.1 Pro Preview Custom Tools, 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 Google: Gemini 3.1 Pro Preview Custom Tools via the Kilo Gateway API with up to 66K output tokens.
Capabilities
Input Modalities
audioimagepdftext
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
Reasoning (per 1M tokens)
Output
$12.00
Frequently Asked Questions
Google: Gemini 3.1 Pro Preview Custom Tools by Kilo Gateway costs $2.00 per 1M input tokens and $12.00 per 1M output tokens.
Model Details
ID
google/gemini-3.1-pro-preview-customtools
Provider
Kilo GatewayFamily
Release Date
Feb 26, 2026
Knowledge Cutoff
N/A
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
KILO_API_KEY
API Base URL
https://api.kilo.ai/api/gateway