GoogleText / ChatGemini 3.1 Pro Preview API: Google's multimodal flagship
Gemini 3.1 Pro Preview via the ApexApi gateway
Gemini 3.1 Pro is Google's flagship multimodal model built for deep native understanding across text, images, and long context, with strong reasoning and grounding. Available through ApexApi's unified, OpenAI-compatible API.
Gemini 3.1 Pro Preview is served through ApexApi's unified, OpenAI-compatible API. One key, one format, with smart routing and automatic failover. Provider: Google AI.
Why Gemini 3.1 Pro Preview
Native multimodality
Reasons across text and images with strong cross-modal grounding.
Very long context
Handles large inputs for document, codebase, and multi-file analysis.
Strong reasoning
Capable general reasoning for analysis, planning, and code.
Specifications
- Modality
- chat
- Context window
- 1048.6K tokens
- Max output
- 65.5K tokens
- Streaming
- Yes
- Tool / function calling
- Yes
- Vision input
- Yes
Gemini 3.1 Pro Preview pricing
Pay-per-use. No subscription, no minimums. Buy credits and pay only for what you call. Transparent, per-call pricing across every model.
Getting started with Gemini 3.1 Pro Preview
OpenAI-compatible. Point your client at ApexApi, swap your key, and call it. No new SDK to learn.
from openai import OpenAI
client = OpenAI(
base_url="https://api.apexapi.dev/v1",
api_key="<YOUR_APEXAPI_KEY>",
)
response = client.chat.completions.create(
model="google/gemini-3.1-pro-preview",
messages=[{"role": "user", "content": "Hello!"}],
)
print(response.choices[0].message.content)Gemini 3.1 Pro Preview use cases
What teams build with Gemini 3.1 Pro Preview on ApexApi.
Document AI
Understand long, mixed-content documents end to end.
Multimodal apps
Vision + text understanding for richer assistants.
Analysis & planning
Complex reasoning over large context windows.
Gemini 3.1 Pro Preview vs other models
How it compares, and on ApexApi you can switch between any of them with a single string change, same key, same endpoint.
Gemini 3.1 Pro Preview vs GPT-5.5
GPT-5.5 emphasizes instruction fidelity and tool orchestration; Gemini 3.1 Pro leans into native multimodality and very long context.
Learn more about GPT-5.5 API →Gemini 3.1 Pro Preview vs Claude Opus 4.7
Opus 4.7 is the long-form text/coding specialist; Gemini 3.1 Pro is the multimodal long-context option.
Learn more about Claude Opus 4.7 API →Why build on ApexApi
One API, every model
OpenAI-compatible. Swap the base URL and key, keep your code. Call 14+ providers and hundreds of models through a single integration.
Smart routing & failover
Per-model provider chains with automatic failover. If one provider degrades, requests route to the next. Your app stays up.
Pay-per-use, no lock-in
Buy credits, pay only for what you call. No subscriptions, no minimums. Switch models anytime with a single string change.
Gemini 3.1 Pro Preview API: FAQ
How do I use the Gemini 3.1 Pro API?
Create an ApexApi key, then point your client at https://api.apexapi.dev/v1 and use the model slug. Send a request to /v1/chat/completions with the model slug. The API is OpenAI-compatible, so most OpenAI SDKs work by changing the base URL and key.
Is the Gemini 3.1 Pro API OpenAI-compatible?
Yes. ApexApi exposes Gemini 3.1 Pro through the same OpenAI-compatible interface used across the whole catalog. Swap the base URL and API key and keep your existing code.
How much does Gemini 3.1 Pro cost on ApexApi?
Pay-per-use. See the live price in the Pricing section above. There's no subscription or minimum; you buy credits and pay only for what you call.
Can I switch from Gemini 3.1 Pro to another model later?
Yes. Change a single string (the model slug) to call any other model in the catalog through the same endpoint and key. No re-integration.
Ready to build with Gemini 3.1 Pro Preview?
One API key. Every major AI model. Pay only for what you use.
Get your API key, free to start