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Gemini 3.1 Pro Preview Custom Tools API1M context

by Google · text+image+file+audio+video->text · released 2026-02-25

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...

Get an API key Try in Chat https://api.datallmlab.com/v1
Input / 1M
$2.00
Output / 1M
$12.00
Context
1M
Providers
1
Cheaper than
13% of catalog

Pricing & specs mirror our live pricing as of July 2026 (pay-as-you-go).

What is 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...

Gemini 3.1 Pro Preview Custom Tools on the release timeline

$0.40$2.19$12.00Gemini 3.1 Pro Preview Custom Tools · $12.002025-062026-022026-05
Each point is a gemini release, placed at its launch date with its current output price (log scale, $/1M). Bubble size ∝ context window; Gemini 3.1 Pro Preview Custom Tools is highlighted. Source: provider catalog, verified July 2026.

Gemini 3.1 Pro Preview Custom Tools pricing

Pay-as-you-go on DataLLM Lab — these are our live list prices (identical to the pricing page):

ModelInput / 1MOutput / 1MCache readCache writeContext
Gemini 3.1 Pro Preview Custom Tools$2.00$12.00$0.20$0.381M

On output price, Gemini 3.1 Pro Preview Custom Tools is cheaper than 13% of the 309 models in the catalog.

What Gemini 3.1 Pro Preview Custom Tools costs per month

WorkloadTokens in / out (monthly)Est. cost
Support chatbot40M / 12M$224
RAG / knowledge base200M / 20M$640
Coding agent80M / 25M$460
Batch extraction150M / 8M$396
Content generation20M / 40M$520

Estimate your own monthly cost

= input × $2.00 + output × $12.00 per 1M · pay-as-you-go, computed in your browser.

Cost = input price × input volume + output price × output volume. The same five workloads run on every model page, so any two compare directly.

Gemini 3.1 Pro Preview Custom Tools vs alternatives

Pick Gemini 3.1 Pro Preview Custom Tools when you want this provider’s capabilities or the 1M context. If price is the only priority, Gemini 2.5 Pro is cheaper per token.
ModelInput / 1MOutput / 1MContextOur test
Gemini 3.1 Pro Preview Custom Tools$2.00$12.001M
Nano Banana Pro (Gemini 3 Pro Image Preview)$2.00$12.0066K
Gemini 3.1 Pro Preview$2.00$12.001M
Gemini 2.5 Pro$1.25$10.001M
Nova Premier 1.0$2.50$12.501M
Command A$2.50$10.00256K

When not to use Gemini 3.1 Pro Preview Custom Tools

Specs

Model IDgoogle/gemini-3.1-pro-preview-customtools
Modalitytext+image+file+audio+video->text (input: text, audio, image, video, file)
Context window1,048,756 tokens
Max output65,536 tokens
Tool / function calling✅ Yes
Structured output (JSON)✅ Yes
Released2026-02-25
Open weights— (hosted API only)

How to call Gemini 3.1 Pro Preview Custom Tools

from openai import OpenAI
client = OpenAI(base_url="https://api.datallmlab.com/v1", api_key="YOUR_DATALLM_LAB_KEY")
resp = client.chat.completions.create(
    model="google/gemini-3.1-pro-preview-customtools",
    messages=[{"role": "user", "content": "Hello"}],
    # supports tools=[...] and tool_choice
)
print(resp.choices[0].message.content)
curl https://api.datallmlab.com/v1/chat/completions \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"google/gemini-3.1-pro-preview-customtools","messages":[{"role":"user","content":"Hello"}]}'
import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://api.datallmlab.com/v1", apiKey: process.env.DATALLM_KEY });
const r = await client.chat.completions.create({
  model: "google/gemini-3.1-pro-preview-customtools",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(r.choices[0].message.content);

The same key routes Gemini 3.1 Pro Preview Custom Tools and 300+ other models — switch models by changing one string. How OpenAI-compatible APIs work.

Prompting tips for Gemini 3.1 Pro Preview Custom Tools

Tips are derived from Gemini 3.1 Pro Preview Custom Tools's actual capabilities — context window, tool & JSON support, modality and price tier — not generic advice.

Open-source tools for Gemini 3.1 Pro Preview Custom Tools

Popular open-source frameworks and agents to build with Gemini 3.1 Pro Preview Custom Tools over the API — star counts pulled from GitHub (July 2026).

googleapis/python-genai★ 3.8K
Google Gen AI Python SDK provides an interface for developers to integrate Google's generative models into the
Official SDK
langgenius/dify★ 147.5K
Production-ready platform for agentic workflow development.
TypeScript
open-webui/open-webui★ 144.0K
User-friendly AI Interface (Supports Ollama, OpenAI API, ...)
Python
langchain-ai/langchain★ 140.8K
The agent engineering platform.
Python
cline/cline★ 64.2K
Autonomous coding agent as an SDK, IDE extension, or CLI assistant.
TypeScript
microsoft/autogen★ 59.5K
A programming framework for agentic AI
Python

Listed by GitHub stars; inclusion is by ecosystem relevance (agent frameworks, SDKs and gateways), not affiliation. Stars change — see each repo for current numbers.

Migrating to Gemini 3.1 Pro Preview Custom Tools

Coming from OpenAI or another gateway? On an OpenAI-compatible setup the only changes are base_url → https://api.datallmlab.com/v1 and model → google/gemini-3.1-pro-preview-customtools. Messages, streaming, tool calls and the rest of your code stay the same. Routing & failover guide.

Rate limits & reliability

Rate limits here are the DataLLM Lab gateway's, not the upstream vendor's. On 429 (rate limited) or 503 (provider busy), retry with exponential backoff. See the error-code guide and failover setup.

Related reading

Gemini API: Pricing & Keys
DataLLM Lab Blog
Gemini vs Claude
DataLLM Lab Blog
How OpenAI-Compatible APIs Work
DataLLM Lab Blog

Call Gemini 3.1 Pro Preview Custom Tools with one key

300+ models behind one OpenAI-compatible endpoint — better prices, better uptime, no subscriptions.

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Frequently asked questions

What is 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... It accepts text, audio, image, video, file input with a 1M-token context window and was released on 2026-02-25. On DataLLM Lab it is callable through one OpenAI-compatible endpoint.

How much does Gemini 3.1 Pro Preview Custom Tools cost?

On DataLLM Lab it is $2.00 per 1M input tokens and $12.00 per 1M output tokens, with cached input at $0.20/1M — cheaper than about 13% of the 309-model catalog on output price. Pay-as-you-go, no subscription.

What is the context window of Gemini 3.1 Pro Preview Custom Tools?

1M tokens, with up to 66K max output tokens.

Is Gemini 3.1 Pro Preview Custom Tools open source?

No open weights are published — it is available through hosted API access only.

How do I call the Gemini 3.1 Pro Preview Custom Tools API?

Point any OpenAI SDK at https://api.datallmlab.com/v1 and set model to "google/gemini-3.1-pro-preview-customtools". One DataLLM Lab key routes this model and 300+ others; no code changes beyond the base URL and model string.

What are good alternatives to Gemini 3.1 Pro Preview Custom Tools?

Close options by price and capability include Nano Banana Pro (Gemini 3 Pro Image Preview), Gemini 3.1 Pro Preview, Gemini 2.5 Pro — all callable with the same DataLLM Lab key.