Skip to contentx402 is live on Robinhood Chain: agents can now pay for any model, per call, in USDG →
OmniRail
← All models

Google · Language model

Gemini 3.1 Pro Preview Custom Tools

google/gemini-3.1-pro-preview-customtools
  • Language
Released Feb 25, 2026

Gemini 3.1 Pro Preview Custom Tools is a variant of Gemini 3.1 Pro that improves tool selection behavior by preventing overuse of a general bash tool when more efficient third-party...

Specifications

Context window
1,048,576 tokens
Max output
65,536 tokens
Input
text, audio, image, video, file
Output
text
Reasoning effort
high, medium, low (always on)
Tokenizer
Gemini

Supported parameters

Accepted by the model and forwarded as-is by the gateway.

  • max_tokens
  • reasoning
  • reasoning_effort
  • response_format
  • seed
  • structured_outputs
  • temperature
  • tool_choice
  • tools
  • top_p

Use it

POST /api/v1/chat/completions · MCP chat · full reference

curl https://omnirail.org/api/v1/chat/completions \
  -H "Authorization: Bearer $OMNIRAIL_KEY" -H "Content-Type: application/json" \
  -d '{"model":"google/gemini-3.1-pro-preview-customtools","messages":[{"role":"user","content":"Hello"}],"max_tokens":300}'