Gemini 3.1 Pro Preview

Google Generally Available

Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation...

Context

tokens

Input

$2.00

per MTok

Output

$12.00

per MTok

Model Page

About

Modalities

Input

Audio file Vision Text Video

Output

Text

Code Examples

curl https://openrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gemini-3.1-pro-preview",
    "messages": [
      { "role": "user", "content": "Explain quantum entanglement in one sentence." }
    ]
  }'

from openai import OpenAI

client = OpenAI(
    base_url="https://openrouter.ai/api/v1",
    api_key=os.environ["OPENROUTER_API_KEY"],
)
response = client.chat.completions.create(
    model="gemini-3.1-pro-preview",
    messages=[
        {"role": "user", "content": "Explain quantum entanglement in one sentence."},
    ],
)
print(response.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://openrouter.ai/api/v1",
  apiKey: process.env.OPENROUTER_API_KEY,
});

const response = await client.chat.completions.create({
  model: "gemini-3.1-pro-preview",
  messages: [
    { role: "user", content: "Explain quantum entanglement in one sentence." },
  ],
});
console.log(response.choices[0].message.content);

API Parameters

Name	Type	Default	Description
`include_reasoning`	boolean	—	Include the model's internal reasoning trace in the response.
`max_tokens` deprecated	integer	—	Deprecated. Use max_completion_tokens.
`reasoning`	object	—	Configuration for extended-thinking / reasoning mode.
`response_format`	one of	—	Constrain output to a JSON schema or an enum (structured outputs).
`seed`	integer	—	Deterministic seed for sampling. Same seed + same prompt produces identical output.
`stop`	array	—	Up to 4 sequences where the API will stop generating tokens.
`structured_outputs`	boolean	—	Enable JSON-schema-constrained output.
`temperature`	number	1	Sampling temperature; higher values produce more random output. 0 is deterministic.
`tool_choice`	one of	—	Controls which (if any) tool is called: "none", "auto", "required", or a specific tool.
`tools`	array	—	List of tools (functions) the model may call.
`top_p`	number	1	Nucleus sampling: consider only tokens whose cumulative probability ≥ top_p.

Standard OpenAI-compatible parameters. Consult the provider docs for model-specific behaviour.