Gemini 3.1 Pro is Google's next-generation multimodal model, optimized for complex reasoning, planning, coding, and multi-turn conversation. Supports text and image inputs. Token-based pricing: $4.00/M input tokens, $24.00/M output tokens. Two endpoints: standard async (/gemini-3-1-pro) and live streaming (/gemini-3-1-pro/stream) via SSE.
About this model
Gemini 3.1 Pro is Google's next-generation multimodal model, optimized for complex reasoning, planning, coding, and multi-turn conversation. It delivers high-quality text and multimodal generations. Pricing: $4.00 per million input tokens and $24.00 per million output tokens.
Cost analysis
| Provider | Cost | Notes |
|---|---|---|
| muapiapp | $4.00/M input tokens, $24.00/M output tokens | Token-based billing. Minimum $0.0006 per call. Highly competitive pricing. |
| Fal.ai | $5.00/M input tokens, $30.00/M output tokens | muapiapp remains more cost-effective. |
| Replicate | $5.20/M input tokens, $31.00/M output tokens | muapiapp remains more cost-effective. |
Token-based billing. Minimum $0.0006 per call. Highly competitive pricing.
muapiapp remains more cost-effective.
muapiapp remains more cost-effective.
** Competitor pricing is estimated based on similar model architectures and usage tiers.
Configuration schema
| Parameter | Type | Description | Default |
|---|---|---|---|
| Prompt | string | The user message or instruction for the model. | Solve this complex coding problem step by step. |
| Image URL | string | Optional image URL to include as multimodal input. | undefined |
| System Prompt | string | Optional system-level instruction to guide model behavior. | You are a helpful software engineering assistant. |
The user message or instruction for the model.
Solve this complex coding problem step by step.Optional image URL to include as multimodal input.
undefinedOptional system-level instruction to guide model behavior.
You are a helpful software engineering assistant.Developer documentation
POST /api/v1/gemini-3-1-pro — returns request_id, poll for result via /api/v1/predictions/{id}/result.
POST /api/v1/gemini-3-1-pro/stream — returns a live SSE stream. Each chunk: data: {"choices":[{"delta":{"content":"text"}}]}, ending with data: [DONE].
See Streaming Documentation for full code examples.
Frequently asked
Pricing is token-based: $4.00 per million input tokens and $24.00 per million output tokens. The minimum charge per call is $0.0006. Actual cost is deducted after each call based on token counts returned by the model.
Yes. Pass an image_url in the request body to include an image as part of the user message.
Yes. You can supply an optional system_prompt field to guide the model's behavior and tone.