Gemini 3.1 Pro Preview Custom Tools API1M context
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...
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
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):
| Model | Input / 1M | Output / 1M | Cache read | Cache write | Context |
|---|---|---|---|---|---|
| Gemini 3.1 Pro Preview Custom Tools | $2.00 | $12.00 | $0.20 | $0.38 | 1M |
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
| Workload | Tokens in / out (monthly) | Est. cost |
|---|---|---|
| Support chatbot | 40M / 12M | $224 |
| RAG / knowledge base | 200M / 20M | $640 |
| Coding agent | 80M / 25M | $460 |
| Batch extraction | 150M / 8M | $396 |
| Content generation | 20M / 40M | $520 |
Estimate your own monthly cost
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
| Model | Input / 1M | Output / 1M | Context | Our test |
|---|---|---|---|---|
| Gemini 3.1 Pro Preview Custom Tools | $2.00 | $12.00 | 1M | — |
| Nano Banana Pro (Gemini 3 Pro Image Preview) | $2.00 | $12.00 | 66K | — |
| Gemini 3.1 Pro Preview | $2.00 | $12.00 | 1M | — |
| Gemini 2.5 Pro | $1.25 | $10.00 | 1M | — |
| Nova Premier 1.0 | $2.50 | $12.50 | 1M | — |
| Command A | $2.50 | $10.00 | 256K | — |
When not to use Gemini 3.1 Pro Preview Custom Tools
- It is premium-priced (output cheaper than only 13% of the catalog) — for routine work a cheaper model likely does the job.
- It is served by a single provider, so there is less failover headroom during an outage.
Specs
| Model ID | google/gemini-3.1-pro-preview-customtools |
| Modality | text+image+file+audio+video->text (input: text, audio, image, video, file) |
| Context window | 1,048,756 tokens |
| Max output | 65,536 tokens |
| Tool / function calling | ✅ Yes |
| Structured output (JSON) | ✅ Yes |
| Released | 2026-02-25 |
| 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
- State the goal, not every step. Gemini 3.1 Pro Preview Custom Tools reasons internally — give it the objective, constraints and success criteria and let it plan the approach; over-scripting each step tends to lower quality. Turn effort up for hard problems.
- Huge 1M context — but anchor the ask. You can paste whole documents or codebases; models attend most to the start and end, so put the key instruction at the top and restate it after long inputs.
- It reads images. Send image parts alongside your text and ask for specific outputs (named JSON fields, a table, "what changed") rather than "describe this".
- Give it real tools. Pass a
tools=[...]schema instead of asking it to "pretend" — let Gemini 3.1 Pro Preview Custom Tools emit tool calls, execute them, and feed results back for the next turn. - Constrain JSON with a schema. Use
response_format/ structured outputs rather than "reply in JSON" to get valid, parseable objects every time.
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).
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
Call Gemini 3.1 Pro Preview Custom Tools with one key
300+ models behind one OpenAI-compatible endpoint — better prices, better uptime, no subscriptions.
Get an API keyCompare pricingFrequently 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.