Google AI / Gemini

The google provider enables integration with Google AI Studio and the Gemini API. It provides access to Google's state-of-the-art language models with support for text, images, and video inputs.

You can use it by specifying one of the available models. Currently, the following models are supported:

Available Models

google:gemini-2.5-flash-preview-04-17 - Latest Flash model with thinking capabilities for enhanced reasoning
google:gemini-2.5-pro-exp-03-25 - Latest thinking model, designed to tackle increasingly complex problems with enhanced reasoning capabilities
google:gemini-2.0-flash-exp - Multimodal model with next generation features
google:gemini-2.0-flash-thinking-exp - Optimized for complex reasoning and problem-solving
google:gemini-1.5-flash-8b - Fast and cost-efficient multimodal model
google:gemini-1.5-pro - Best performing multimodal model for complex reasoning
google:gemini-pro - General purpose text and chat
google:gemini-pro-vision - Multimodal understanding (text + vision)

tip

If you are using Google Vertex, see the vertex provider.

Configuration

GOOGLE_API_KEY (required) - Google AI Studio API key
GOOGLE_API_HOST - used to override the Google API host, defaults to generativelanguage.googleapis.com

Basic Configuration

The provider supports various configuration options that can be used to customize the behavior of the model:

providers:
  - id: google:gemini-1.5-pro
    config:
      temperature: 0.7 # Controls randomness (0.0 to 1.0)
      maxOutputTokens: 2048 # Maximum length of response
      topP: 0.9 # Nucleus sampling
      topK: 40 # Top-k sampling
      stopSequences: ['END'] # Stop generation at these sequences

Thinking Configuration

For models that support thinking capabilities (like Gemini 2.5 Flash), you can configure the thinking budget:

providers:
  - id: google:gemini-2.5-flash-preview-04-17
    config:
      generationConfig:
        temperature: 0.7
        maxOutputTokens: 2048
        thinkingConfig:
          thinkingBudget: 1024 # Controls tokens allocated for thinking process

The thinking configuration allows the model to show its reasoning process before providing the final answer, which can be helpful for complex tasks that require step-by-step thinking.

You can also specify a response schema for structured output:

providers:
  - id: google:gemini-1.5-pro
    config:
      generationConfig:
        response_mime_type: application/json
        response_schema:
          type: object
          properties:
            foo:
              type: string

For multimodal inputs (images and video), the provider supports:

Images: PNG, JPEG, WEBP, HEIC, HEIF formats (max 3,600 files)
Videos: MP4, MPEG, MOV, AVI, FLV, MPG, WEBM, WMV, 3GPP formats (up to ~1 hour)

Safety Settings

Safety settings can be configured to control content filtering:

providers:
  - id: google:gemini-1.5-pro
    config:
      safetySettings:
        - category: HARM_CATEGORY_DANGEROUS_CONTENT
          probability: BLOCK_ONLY_HIGH # or other thresholds

For more details on capabilities and configuration options, see the Gemini API documentation.

Model Examples

Gemini 2.0 Flash

Best for fast, efficient responses and general tasks:

providers:
  - id: google:gemini-2.0-flash
    config:
      temperature: 0.7
      maxOutputTokens: 2048
      topP: 0.9
      topK: 40

Advanced Features

Function Calling

Enable your model to interact with external systems through defined functions:

providers:
  - id: google:gemini-1.5-pro
    config:
      tools:
        function_declarations:
          - name: 'get_weather'
            description: 'Get current weather for a location'
            parameters:
              type: 'object'
              properties:
                location:
                  type: 'string'
                  description: 'City name or coordinates'
                units:
                  type: 'string'
                  enum: ['celsius', 'fahrenheit']
              required: ['location']
      tool_config:
        function_calling_config:
          mode: 'auto' # or 'none' to disable

Structured Output

You can constrain the model to output structured JSON responses in two ways:

1. Using Response Schema Configuration

providers:
  - id: google:gemini-1.5-pro
    config:
      generationConfig:
        response_mime_type: 'application/json'
        response_schema:
          type: 'object'
          properties:
            title:
              type: 'string'
            summary:
              type: 'string'
            tags:
              type: 'array'
              items:
                type: 'string'
          required: ['title', 'summary']

2. Using Response Schema File

providers:
  - id: google:gemini-1.5-pro
    config:
      # Can be inline schema or file path
      responseSchema: 'file://path/to/schema.json'

For more details, see the Gemini API documentation.

Google Live API

Promptfoo now supports Google's WebSocket-based Live API, which enables low-latency bidirectional voice and video interactions with Gemini models. This API provides real-time interactive capabilities beyond what's available in the standard REST API.

Using the Live Provider

Access the Live API by specifying the model with the 'live' service type:

providers:
  - id: 'google:live:gemini-2.0-flash-exp'
    config:
      generationConfig:
        response_modalities: ['text']
      timeoutMs: 10000

Key Features

Real-time bidirectional communication: Uses WebSockets for faster responses
Multimodal capabilities: Can process text, audio, and video inputs
Built-in tools: Supports function calling, code execution, and Google Search integration
Low-latency interactions: Optimized for conversational applications
Session memory: The model retains context throughout the session

Function Calling Example

The Live API supports function calling, allowing you to define tools that the model can use:

providers:
  - id: 'google:live:gemini-2.0-flash-exp'
    config:
      tools: file://tools.json
      generationConfig:
        response_modalities: ['text']
      timeoutMs: 10000

Where tools.json contains function declarations and built-in tools:

[
  {
    "functionDeclarations": [
      {
        "name": "get_weather",
        "description": "Get current weather information for a city",
        "parameters": {
          "type": "OBJECT",
          "properties": {
            "city": {
              "type": "STRING",
              "description": "The name of the city to get weather for"
            }
          },
          "required": ["city"]
        }
      }
    ]
  },
  {
    "codeExecution": {}
  },
  {
    "googleSearch": {}
  }
]

Built-in Tools

The Live API includes several built-in tools:

Code Execution: Execute Python code directly in the model's runtime
```
{
  "codeExecution": {}
}
```
Google Search: Perform real-time web searches
```
{
  "googleSearch": {}
}
```

Getting Started

Try the examples:

# Basic text-only example
promptfoo init --example google-live

# Function calling and tools example
promptfoo init --example google-live-tools

Limitations

Sessions are limited to 15 minutes for audio or 2 minutes of audio and video
Token counting is not supported
Rate limits of 3 concurrent sessions per API key apply
Maximum of 4M tokens per minute

For more details, see the Live API documentation.

Available Models​

Configuration​

Basic Configuration​

Thinking Configuration​

Safety Settings​

Model Examples​

Gemini 2.0 Flash​

Advanced Features​

Function Calling​

Structured Output​

1. Using Response Schema Configuration​

2. Using Response Schema File​

Google Live API​

Using the Live Provider​

Key Features​

Function Calling Example​

Built-in Tools​

Getting Started​

Limitations​