Gemini 3.1 Pro Preview Custom Tools is a specialized variant of Google's Gemini 3.1 Pro designed to improve tool use in complex agentic workflows. It increases function calling reliability and steers the model toward registered custom functions instead of defaulting to a generic bash tool, which makes it well suited to coding agents and multi-tool systems where the model must pick the right tool for each task. With a 1M token context window and strong reasoning, the model retains Gemini 3.1 Pro's multimodal understanding across text, images, video, audio, and code. It is aimed at developers building agents that orchestrate many custom tools and APIs, where consistent and accurate tool selection matters more than raw breadth.
Gemini 3.1 Pro Preview Custom Tools runs on 1 route through the Opper gateway. Compare residency, ZDR, and training posture at a glance — full data-handling detail per route below.
| Provider | Region | Zero data retention | Training | Input | Output |
|---|---|---|---|---|---|
| US | Enterprise | No | $2.00 | $12.00 |
Training posture across routes: No training on prompts by default.
Each route hosting Gemini 3.1 Pro Preview Custom Tools has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Call Gemini 3.1 Pro Preview Custom Tools through the Opper gateway with one API key. Let your coding agent set it up, or call it directly — Opper is drop-in compatible with the OpenAI, Anthropic, and Google AI SDKs.
Copy this and paste it into your coding agent — Claude Code, Cursor, Codex, and more — and it'll wire up Opper for you.
import OpenAI from "openai";const client = new OpenAI({apiKey: process.env.OPPER_API_KEY,baseURL: "https://api.opper.click/v3/compat",});const completion = await client.chat.completions.create({model: "gemini/gemini-3.1-pro-preview-customtools",messages: [{ role: "user", content: "Hello" }],});console.log(completion.choices[0].message.content);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
