Using Gemini 3.1 Pro Preview Custom Tools on Google AI Studio

Implementation guide · Gemini 3.1 · Google DeepMind

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Google AI Studio exposes Gemini 3.1 Pro Preview Custom Tools through model ID gemini-3.1-pro-preview-customtools. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.

Last refreshed 2026-06-15. Next refresh: weekly.

Quick Start

1
Create an account at Google AI Studio and generate an API key.
2
Use the Google AI Studio SDK or REST API to call gemini-3.1-pro-preview-customtools — see the documentation for request format.
3
You'll be billed $2.00/1M input, $12.00/1M output tokens. See full pricing.

API Portal Documentation Pricing Model Card

Code Examples

Install

pip install google-genai

API key

GOOGLE_API_KEY

Model ID

gemini-3.1-pro-preview-customtools

Use the model name directly, e.g. "gemini-2.0-flash", "gemini-1.5-pro", or "gemini-2.5-pro-preview-05-06".

import os
from google import genai

client = genai.Client(api_key=os.environ["GOOGLE_API_KEY"])
response = client.models.generate_content(
    model="gemini-3.1-pro-preview-customtools",
    contents="Hello"
)
print(response.text)

Pricing on Google AI Studio

Type	Price (per 1M)
Input tokens	$2.00
Output tokens	$12.00

Capabilities

VisionMultimodalStructured Outputs

About Gemini 3.1 Pro Preview Custom Tools

Google: Gemini 3.1 Pro Preview Custom Tools available via OpenRouter. Pricing: $2/1M input, $12/1M output.

Full model details →

Model Specs

Released2026-01-01

Context1m

ArchitectureDecoder Only

Knowledge cutoff2025-01