promptfoo/examples/google-imagen

google-imagen

This example demonstrates Google Imagen image generation models.

You can run this example with:

npx promptfoo@latest init --example google-imagen

Prerequisites

You can use Imagen models through either Google AI Studio or Vertex AI:

Option 1: Google AI Studio (Quick Start, Limited Features)

• Get an API key from Google AI Studio
• Supports: Imagen 4 models only
• Limitations: No seed or addWatermark parameters

Option 2: Vertex AI (Full Features)

• Google Cloud project with billing enabled
• Vertex AI API enabled
• Authentication via gcloud auth application-default login
• Supports: All Imagen models and all parameters

Setup

For Google AI Studio:

# Set your API key (Unix/Linux/macOS)
export GOOGLE_API_KEY=your-api-key

# For Windows Command Prompt:
# set GOOGLE_API_KEY=your-api-key

# For Windows PowerShell:
# $env:GOOGLE_API_KEY="your-api-key"

For Vertex AI:

# Enable Vertex AI API
gcloud services enable aiplatform.googleapis.com

# Authenticate
gcloud auth application-default login

# Set project ID (Unix/Linux/macOS)
export GOOGLE_PROJECT_ID=your-project-id

# For Windows Command Prompt:
# set GOOGLE_PROJECT_ID=your-project-id

# For Windows PowerShell:
# $env:GOOGLE_PROJECT_ID="your-project-id"

Environment Variables

• GOOGLE_API_KEY - Google AI Studio API key (Option 1)
• GOOGLE_PROJECT_ID - Your Google Cloud project ID (Option 2)

Available Models

• imagen-4.0-ultra-generate-preview-06-06 - Ultra quality ($0.06/image)
• imagen-4.0-generate-preview-06-06 - Standard quality ($0.04/image)
• imagen-4.0-fast-generate-preview-06-06 - Fast generation ($0.02/image)
• imagen-3.0-generate-002 - Imagen 3.0 ($0.04/image)

Running the Example

npx promptfoo@latest eval

Notes

• Imagen models are available through both Google AI Studio and Vertex AI
• Google AI Studio:
  • Uses API key authentication (quick start)
  • Only supports Imagen 4 models (4.0 preview models)
  • Limited parameter support:
    • No seed or addWatermark parameters
    • Only block_low_and_above safety filter level
• Vertex AI:
  • Requires authentication via gcloud auth application-default login
  • Supports all Imagen models (both 3.0 and 4.0)
  • Full parameter support:
    • All safety filter levels (block_most, block_some, block_few, block_fewest)
    • seed for deterministic generation
    • addWatermark control
  • You must provide a Google Cloud project ID either via:
    • GOOGLE_PROJECT_ID environment variable
    • projectId in the provider config
• Seed and watermark parameters are mutually exclusive (Vertex AI only)

Advanced Configuration

See promptfooconfig-advanced.yaml for examples of platform-specific configurations that take advantage of each platform's unique capabilities.