Google: Gemini 3.1 Pro Preview Custom Tools

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...

Context
1.0M
Max output
66K
Input price
$2/1M tokens
Output price
$12/1M tokens

Capabilities

Reasoning & Interaction
Reasoning
Tool Calling
Output Control
Structured Output
JSON Mode

Details

Model IDgoogle/gemini-3.1-pro-preview-customtools
Provider OpenRouter
Creator Google AI
Familygemini-3.1
License—
Status—
Typechat
Input modalitiestext, audio, image, video
Output modalitiestext
Open weight—
Parameters—
Architecture—
Context window1.0M tokens
Max input—
Max output66K tokens
Reasoning tokens—
Knowledge cutoff—
Release date
Sourceofficial

Tools

Function Callingfunction_calling
Call external functions and APIs

Pricing

Input
$2
Output
$12
Cache write
—
Cache read
$0.2
Batch in
—
Batch out
—

Family Comparison: gemini-3.1

ModelContextMax outPricing
Google: Gemini 3.1 Flash Lite (batch)1.0M66K$0.13$0.75
Google: Nano Banana 2 Lite (Gemini 3.1 Flash Lite Image)66K59K$0.25$1.5
Google: Gemini 3.1 Flash Lite Preview1.0M66K$0.25$1.5
Google: Gemini 3.1 Flash Lite1.0M66K$0.25$1.5
Google: Nano Banana 2 (Gemini 3.1 Flash Image Preview)66K59K$0.5$3
Google: Nano Banana 2 (Gemini 3.1 Flash Image)131K33K$0.5$3
Google: Gemini 3.1 Pro Preview (batch)1.0M66K$1$6
Google: Gemini 3.1 Pro Preview Custom Tools1.0M66K$2$12
Google: Gemini 3.1 Pro Preview1.0M66K$2$12

API

GET/v1/models/openrouter/google/gemini-3.1-pro-preview-customtools

Google: Gemini 3.1 Pro Preview Custom Tools

google/gemini-3.1-pro-preview-customtools

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...

Changes · 6 entries
google/gemini-3.1-pro-preview-customtoolsupdatebf78dcfJul 25, 2026, 05:49 AM
context_window1048756→1048576
google/gemini-3.1-pro-preview-customtoolsupdate73d11c6May 18, 2026, 03:39 AM
context_window1048576→1048756
google/gemini-3.1-pro-preview-customtoolsupdate82e6976Apr 7, 2026, 02:37 PM
descriptionGemini 3.1 Pro Preview Custom Tools is a variant of Gemin...→Gemini 3.1 Pro Preview Custom Tools is a variant of Gemin...
google/gemini-3.1-pro-preview-customtoolsupdate1cd659eMar 24, 2026, 04:19 AM
capabilitiesjson modeyes
google/gemini-3.1-pro-preview-customtoolsupdate2b100acMar 23, 2026, 05:30 AM
model_typechat
release_date2026-02-25
taglineGemini 3.1 Pro Preview Custom Tools is a variant of Gemin...
tools["function_calling"]
google/gemini-3.1-pro-preview-customtoolscreate7f5c66fMar 21, 2026, 05:16 AM