Gemini 3.1 Pro Preview Customtools

gemini-3.1-pro-preview-customtools · Google

gemini-3.1-pro-preview-customtools For users who build applications mixing bash and custom tools, the Gemini 3.1 Pro preview provides a separate endpoint accessible via the API call gemini-3.1-pro-preview-customtools. This endpoint is better at prioritizing your custom tools (for example, view_file or search_code). Please note that while gemini-3.1-pro-preview-customtools is optimized for agent workflows that use custom tools and Bash, you may experience quality fluctuations in some use cases that cannot benefit from these tools.

API Pricing

Input$2 / 1M tokens
Output$12 / 1M tokens
Cache read$0.5 / 1M tokens

Specifications

Context1.05M tokens
Modalitiestext, image, video, audio, PDF
CapabilitiesThinking, Tool calling, Web search, URL context, Code interpreter, File search, Structured outputs, Prompt caching
Endpointschat_completions, gemini_api, claude_api

Frequently asked questions

What is Gemini 3.1 Pro Preview Customtools?

gemini-3.1-pro-preview-customtools For users who build applications mixing bash and custom tools, the Gemini 3.1 Pro preview provides a separate endpoint accessible via the API call gemini-3.1-pro-preview-customtools. This endpoint is better at prioritizing your custom tools (for example, view_file or search_code). Please note that while gemini-3.1-pro-preview-customtools is optimized for agent workflows that use custom tools and Bash, you may experience quality fluctuations in some use cases that cannot benefit from these tools.

What is the context length of Gemini 3.1 Pro Preview Customtools?

Gemini 3.1 Pro Preview Customtools has a 1,048,576 token context window.

How much does Gemini 3.1 Pro Preview Customtools cost?

On AIHubMix, Gemini 3.1 Pro Preview Customtools costs $2 per million input tokens and $12 per million output tokens. Cached input reads are billed at $0.5 per million tokens.

What modalities does Gemini 3.1 Pro Preview Customtools support?

Gemini 3.1 Pro Preview Customtools accepts text, image, video, audio and PDF input.

What capabilities does Gemini 3.1 Pro Preview Customtools support?

Gemini 3.1 Pro Preview Customtools supports thinking, tool calling, function calling, structured outputs, web search, deep search and long context. Per-protocol parameter support is listed in the capability table on this page.

How do I call Gemini 3.1 Pro Preview Customtools via API?

Gemini 3.1 Pro Preview Customtools is available through the AIHubMix unified API. The API is OpenAI-compatible: point your OpenAI SDK at https://aihubmix.com/v1, use your AIHubMix API key, and set the model name to gemini-3.1-pro-preview-customtools — no other code changes needed.

Who created Gemini 3.1 Pro Preview Customtools?

Gemini 3.1 Pro Preview Customtools is developed by Google. AIHubMix aggregates it alongside models from other providers behind one API and one bill.

When was Gemini 3.1 Pro Preview Customtools released?

Gemini 3.1 Pro Preview Customtools was released on February 19, 2026 by Google.

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Use Gemini 3.1 Pro Preview Customtools via the AIHubMix unified API — one interface for every major LLM.