> ## Documentation Index
> Fetch the complete documentation index at: https://docs.crazyrouter.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Gemini Native Format

> Production-revalidated Gemini 3 Pro native API usage on Crazyrouter

> Last updated: 2026-06-06

# Gemini Native Format

This page only documents Gemini Native behavior that was revalidated against Crazyrouter production on `2026-03-22`.

Current primary example model:

* `gemini-3.1-pro`

Dedicated multimodal pages based on successful request patterns:

* [Gemini Image Understanding](/en/chat/gemini/vision)
* [Gemini Video Understanding](/en/chat/gemini/video)
* [Gemini Audio Understanding](/en/chat/gemini/audio)

## Endpoints

```text theme={null}
POST /v1beta/models/{model}:generateContent
POST /v1beta/models/{model}:streamGenerateContent
```

## Authentication

Pass the API key through the URL parameter:

```text theme={null}
?key=YOUR_API_KEY
```

***

## Basic text generation

```bash cURL theme={null}
curl "https://api.crazyrouter.com/v1beta/models/gemini-3.1-pro:generateContent?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "Explain machine learning in one sentence."
          }
        ]
      }
    ],
    "generationConfig": {
      "maxOutputTokens": 128
    }
  }'
```

Verified response shape:

```json theme={null}
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "text": "...",
            "thoughtSignature": "..."
          }
        ]
      }
    }
  ]
}
```

***

## Streaming generation

This recheck confirmed that `streamGenerateContent` returns incremental SSE output.

```bash cURL theme={null}
curl "https://api.crazyrouter.com/v1beta/models/gemini-3.1-pro:streamGenerateContent?key=YOUR_API_KEY&alt=sse" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "Write one short sentence about AI."
          }
        ]
      }
    ]
  }'
```

Observed SSE chunk shape:

```text theme={null}
data: {"candidates":[{"content":{"parts":[{"text":"...","thoughtSignature":"..."}]}}]}
```

***

## Structured outputs

This production recheck confirmed that `responseMimeType + responseSchema` works:

```bash cURL theme={null}
curl "https://api.crazyrouter.com/v1beta/models/gemini-3.1-pro:generateContent?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "Return a JSON object with keys city and country for Tokyo."
          }
        ]
      }
    ],
    "generationConfig": {
      "responseMimeType": "application/json",
      "responseSchema": {
        "type": "object",
        "properties": {
          "city": {"type": "string"},
          "country": {"type": "string"}
        },
        "required": ["city", "country"]
      }
    }
  }'
```

Verified production output:

```json theme={null}
{"city":"Tokyo","country":"Japan"}
```

***

## Google Search

This production recheck confirmed that the `googleSearch` tool works:

```bash cURL theme={null}
curl "https://api.crazyrouter.com/v1beta/models/gemini-3.1-pro:generateContent?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "Use Google Search to find one recent headline from a major technology news site."
          }
        ]
      }
    ],
    "tools": [
      {
        "googleSearch": {}
      }
    ]
  }'
```

Verified fields include:

* `groundingMetadata.webSearchQueries`
* `groundingMetadata.groundingChunks`
* `groundingMetadata.groundingSupports`

***

## Thinking

This production recheck confirmed that `thinkingConfig` works:

```bash cURL theme={null}
curl "https://api.crazyrouter.com/v1beta/models/gemini-3.1-pro:generateContent?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "Which is larger, 9.11 or 9.9? Explain briefly."
          }
        ]
      }
    ],
    "generationConfig": {
      "thinkingConfig": {
        "thinkingBudget": 256
      },
      "maxOutputTokens": 512
    }
  }'
```

Verified marker:

```json theme={null}
{
  "usageMetadata": {
    "thoughtsTokenCount": 120
  }
}
```

***

## Common `generationConfig` fields

| Field              | Type    | Description                      |
| ------------------ | ------- | -------------------------------- |
| `maxOutputTokens`  | integer | Maximum output tokens            |
| `temperature`      | number  | Sampling temperature             |
| `responseMimeType` | string  | MIME type for structured outputs |
| `responseSchema`   | object  | Structured output constraint     |
| `thinkingConfig`   | object  | Thinking mode configuration      |

<Note>
  Gemini Native uses the `contents[].parts[]` structure rather than OpenAI-style `messages`. If you want an OpenAI-style route instead, use [Gemini OpenAI-Compatible Format](/en/chat/gemini/openai-compat).
</Note>

Related pages:

* [Official Model Pricing Methods](/en/reference/official-pricing-methods)