Hyphen OpenFeature Provider for Go

This repository contains the Hyphen Provider implementation for the OpenFeature Go SDK.

Table of Contents

1. Installation
2. Usage
3. Configuration
4. Development
5. Contributing
6. License

Installation

go get github.com/hyphen/openfeature-provider-go
go get github.com/open-feature/go-sdk

Usage

Quick Start

package main

import (
    "context"
    "log"
    "github.com/open-feature/go-sdk/openfeature"
    "github.com/hyphen/openfeature-provider-go/pkg/toggle"
)

func main() {
    // Initialize the provider
    provider, err := toggle.NewProvider(toggle.Config{
        PublicKey:   "your-public-key",
        Application: "your-app",
        Environment: "development", // Or "pevr_abc123" using project environment ID format
    })
    if err != nil {
        log.Fatal(err)
    }

    // Set as global provider
    openfeature.SetProvider(provider)

    // Create a client
    client := openfeature.NewClient("my-app")

    // Create evaluation context
    ctx := openfeature.NewEvaluationContext(
        "user-123",
        map[string]interface{}{
            "email": "[email protected]",
            "plan":  "premium",
        },
    )

    // Evaluate different types of flags
    boolFlag, _ := client.BooleanValue(context.Background(), "my-bool-flag", false, ctx)
    stringFlag, _ := client.StringValue(context.Background(), "my-string-flag", "default", ctx)
    numberFlag, _ := client.NumberValue(context.Background(), "my-number-flag", 0, ctx)

    log.Printf("Bool Flag: %v", boolFlag)
    log.Printf("String Flag: %s", stringFlag)
    log.Printf("Number Flag: %f", numberFlag)
}

Advanced Usage

Evaluation Context

The evaluation context allows you to pass targeting information:

ctx := openfeature.NewEvaluationContext(
    "user-123",
    map[string]interface{}{
        "email":      "[email protected]",
        "plan":       "premium",
        "age":        25,
        "country":    "US",
        "beta_user":  true,
    },
)

Caching Configuration

Configure caching to improve performance:

config := toggle.Config{
    PublicKey:   "your-public-key",
    Application: "your-app",
    Environment: "development",
    Cache: &toggle.CacheConfig{
        TTL: time.Minute * 5,
        KeyGen: func(ctx toggle.EvaluationContext) string {
            return fmt.Sprintf("%s-%s", ctx.TargetingKey, ctx.GetValue("plan"))
        },
    },
}

Usage Telemetry

By default, the provider sends telemetry data about feature flag evaluations to Hyphen (EnableUsage is true). To disable usage telemetry, you can set EnableUsage to false in the configuration:

disableUsage := false
provider, err := toggle.NewProvider(toggle.Config{
    PublicKey:   "your-public-key",
    Application: "your-app",
    // Using alternateId format:
    Environment: "development",
    // OR using project environment ID format:
    // Environment: "pevr_abc123",
    EnableUsage: &disableUsage, // Disable usage telemetry
})

Note: Since EnableUsage is a pointer to bool, you need to first declare a boolean variable and then pass its address to the configuration.

Configuration

Provider Options

Option	Type	Required	Description
PublicKey	string	Yes	Your Hyphen API public key.
Application	string	Yes	The application id or alternate id.
Environment	string	Yes	The environment identifier for the Hyphen project (project environment ID or alternateId).
HorizonUrls	[]string	No	Hyphen Horizon URLs for fetching flags.
EnableUsage	bool	No	Enable/disable telemetry (default: true).
Cache	object	No	Configuration for caching feature flag evaluations.

Caching

The provider supports caching of evaluation results:

Property	Type	Default	Description
TTL	number	300	Time-to-live in seconds for cached flag evaluations.
KeyGen	Function	-	Custom function to generate cache keys from evaluation context.

Example with cache configuration:

config := toggle.Config{
    PublicKey:   "your-public-key",
    Application: "your-app",
    // Using alternateId format:
    Environment: "development",
    // OR using project environment ID format:
    // Environment: "pevr_abc123",
    Cache: &toggle.CacheConfig{
        TTL: time.Minute * 5,
        KeyGen: func(ctx toggle.EvaluationContext) string {
            return ctx.TargetingKey
        },
    },
}

Development

Requirements

• Go 1.19 or higher

Running Tests

go test ./...

Building

go build ./...

Contributing

We welcome contributions to this project! If you'd like to contribute, please follow the guidelines outlined in CONTRIBUTING.md. Whether it's reporting issues, suggesting new features, or submitting pull requests, your help is greatly appreciated!

License

This project is licensed under the MIT License. See the LICENSE file for full details.