OpenFeature Provider for Go

ConfigCat OpenFeature Provider for Go on GitHub

Getting started

1. Install the provider

go get github.com/open-feature/go-sdk-contrib/providers/configcat

2. Initialize the provider

The ConfigCat Provider needs a pre-configured ConfigCat Go SDK client:

import (
    "context"

    sdk "github.com/configcat/go-sdk/v9"
    configcat "github.com/open-feature/go-sdk-contrib/providers/configcat/pkg"
    "github.com/open-feature/go-sdk/openfeature"
)

// Configure the ConfigCat SDK.
configcatClient := sdk.NewCustomClient(sdk.Config{SDKKey: "#YOUR-SDK-KEY#",
    PollingMode: sdk.AutoPoll,
    PollInterval: time.Second * 60})

// Configure the provider.
openfeature.SetProvider(configcat.NewProvider(configcatClient))

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

For more information about all the configuration options, see the Go SDK documentation.

3. Evaluate your feature flag

isAwesomeFeatureEnabled, err := client.BooleanValue(
    context.Background(), "isAwesomeFeatureEnabled", false, openfeature.EvaluationContext{},
)

if err == nil && isAwesomeFeatureEnabled {
    doTheNewThing()
} else {
    doTheOldThing()
}

Evaluation Context

An evaluation context in the OpenFeature specification is a container for arbitrary contextual data that can be used as a basis for feature flag evaluation. The ConfigCat provider translates these evaluation contexts to ConfigCat User Objects.

The following table shows how the different context attributes are mapped to User Object attributes.

Evaluation context	User Object	Required
openfeature.TargetingKey	Identifier	☑
configcat.EmailKey	Email
configcat.CountryKey	Country
Any other	Custom

To evaluate feature flags for a context, use the OpenFeature Evaluation API:

registeredAt, _ := time.Parse(time.DateTime, "2023-11-22 12:34:56")
context := openfeature.NewEvaluationContext("#SOME-USER-ID#", map[string]any{
    configcat.EmailKey: "[email protected]",
    configcat.CountryKey: "CountryID",
    "Rating": 4.5,
    "RegisteredAt": registeredAt,
    "Roles": []string{"Role1","Role2"},
})

isAwesomeFeatureEnabled, err := client.BooleanValue(
    context.Background(), "isAwesomeFeatureEnabled", false, context,
)

Look under the hood

• ConfigCat OpenFeature Provider's repository on GitHub