Reasoning-first Gemini preview for agentic coding and complex problem solving
Gemini 3.1 Pro Preview Custom Tools is listed for chat workloads and supports a 1.0M context window.
Use it when OpenRouter's free tier is enough for evaluation, demos, or light production traffic.
We only found this Gemini 3.1 Pro Preview Custom Tools listing on OpenRouter in the current catalog. Use the related models section for nearby alternatives.
| Provider | Model listing | Access | Context | API | Limits |
|---|---|---|---|---|---|
| | Gemini 3.1 Pro Preview Custom Tools | Free tier | 1.0M | Native | 200 req/day (free tier) |
| Model | Provider | Context | Access |
|---|---|---|---|
| Poolside: Laguna XS 2.1 (free) | OpenRouter | 262K | Free tier |
| Cohere: North Mini Code (free) | OpenRouter | 256K | Free tier |
| NVIDIA: Nemotron 3.5 Content Safety (free) | OpenRouter | 128K | Free tier |
| NVIDIA: Nemotron 3 Ultra (free) | OpenRouter | 1.0M | Free tier |
| NVIDIA: Nemotron 3 Nano Omni (free) | OpenRouter | 256K | Free tier |
Gemini 3.1 Pro Preview Custom Tools is tagged for chat in this catalog.
Gemini 3.1 Pro Preview Custom Tools is listed with free API access on OpenRouter, subject to the provider's quota and account policy.
The model ID shown in this catalog is google/gemini-3.1-pro-preview.
The listed free tier limit is 200 req/day (free tier). Limits can change per account tier, so confirm against the provider dashboard.
The listed context window is 1.0M tokens with up to 66K output tokens.
Free Gemini 3.1 Pro Preview Custom Tools API.
For API keys, setup steps, and provider-level limits, see the OpenRouter provider page.