promptfoo/examples/golang-provider

Golang Provider Example

This example demonstrates how to structure a Go-based provider for promptfoo. For detailed documentation, see Go Provider documentation.

To get started with this example:

promptfoo init --example golang-provider

Directory Structure

This example shows two implementations of the same provider interface:

golang-provider/
├── go.mod            # Root module definition
├── main.go           # Root provider implementation
├── core/             # Supporting code
│   └── openai.go     # OpenAI client wrapper
├── pkg1/             # Shared utilities
│   └── utils.go      # Configuration
├── evaluation/       # Alternative implementation
│   └── main.go      # Provider with same interface
└── promptfooconfig.yml  # Config comparing both implementations

The structure demonstrates how to:

1. Keep shared Go code in a single module
2. Implement the same provider interface in different ways
3. Compare multiple implementations in one config

Prerequisites

1. Go installed (1.16 or later)

2. OpenAI Go client library:

   go get github.com/sashabaranov/go-openai@v1.37.0
   

3. Set your API key:

   export OPENAI_API_KEY=your_key_here
   

Usage

Run the comparison:

npx promptfoo eval

Then view the results with:

npx promptfoo view

Configuration

The config compares both implementations:

providers:
  - id: 'file://evaluation/main.go:CallApi'
    label: 'Provider in evaluation/'

  - id: 'file://main.go:CallApi'
    label: 'Provider in root'
    config:
      reasoning_effort: 'high'

Provider Implementations

Both main.go and evaluation/main.go implement the same interface:

func CallApi(prompt string, options map[string]interface{}) (string, error)

They share the same OpenAI client code but can be configured differently through the config file.