🎛️ GO Feature Flag

:pray: If you are using GO Feature Flag please consider to add yourself in the adopters list.
This simple act significantly boosts the project's visibility and credibility, making a substantial contribution to its advancement.

If you want to support me and GO Feature Flag, you can also become a sponsor.

Table of Contents

• 🎛️ GO Feature Flag
  • Table of Contents
  • What is GO Feature Flag?
  • What can I do with GO Feature Flag?
  • Part of the OpenFeature Ecosystem
  • Getting started
    • Create a feature flag configuration
    • Create a relay proxy configuration file
    • Install the relay proxy
    • Use Open Feature SDK
      • Install dependencies
      • Init your Open Feature client
      • Evaluate your flag
    • Installation
    • Create a feature flag configuration
    • SDK Initialisation
    • Evaluate your flags
  • Can I use GO Feature Flag with any language?
  • Where do I store my flags file?
  • Flags file format
  • Rule format
    • Examples
  • Evaluation Context
  • Custom bucketing
  • Variations
    • Example
  • Rollout
    • Complex rollout strategy available
  • Notifiers
  • Export data
  • Cli
• How can I contribute?
  • Contributors
  • Sponsors
  • Adopters

What is GO Feature Flag?

GO Feature Flag is a lightweight and open-source solution that provides a simple and complete feature flag implementation.

The solution has been built to facilitate the usage of feature flags in your code with the easiest setup possible.

Originally, GO Feature Flag was designed as a solution exclusively for the GO language. With the new standardization of feature flags by the Openfeature project, the solution is now available for multiple languages (list of supported languages) through a simple API server called the relay proxy, which can be hosted.

[!TIP] If you are not familiar with feature flags, I've written an article which explains why feature flags can fasten your iteration cycle.

What can I do with GO Feature Flag?

• Use the feature flag standard OpenFeature in your favorite language (see list).
• Storing your configuration flags file on various locations (HTTP, S3, Kubernetes, see full list).
• Configuring your flags in various format (JSON, TOML and YAML).
• Adding complex rules to target your users.
• Use a complex rollout strategy for your flags :
  • Run A/B testing experimentation.
  • Progressively rollout a feature.
  • Schedule your flag updates.
• Exporting your flags usage data to various destinations such as (S3, Google cloud storage, file, Kafka, see the full list).
• Getting notified when a flag has been changed (webhook and slack).
• Support your full stack, from the backend to the frontend including your mobile apps.

https://github.com/user-attachments/assets/56e1a2a2-996f-4db8-9c93-28c057e4ed5a

The code of this demo is available in examples/demo repository.

Part of the OpenFeature Ecosystem

At GO Feature Flag, we believe in the power of open standards and, the importance of vendor neutrality. That's why we've chosen to rely on Open Feature for our SDKs.

By adopting GO Feature Flag you embrace the OpenFeature standard and you get all the benefits of the ecosystem.

• Open-Source standard SDKs
• No Vendor Lock-In
• OpenFeature community based support for SDKs

Getting started

[!IMPORTANT] Before starting to use GO Feature Flag you should decide if you want to use Open Feature SDKs or if you want to use GO Feature Flag as a GO Module.

We recommend using the relay-proxy for a central flag management and evaluation solution, it enables the multi-languages support, and it integrates seamlessly with the Open Feature SDKs.
This is the best way to get full potential of GO Feature Flag.

If your project is exclusively in GO, the GO module is an option. It will perform the flag evaluation directly in your GO code.

Create a feature flag configuration

Create a new YAML file containing your first flag configuration.

# 20% of the users will use the variation "my-new-feature"
test-flag:
  variations:
    my-new-feature: true
    my-old-feature: false
  defaultRule:
    percentage:
      my-new-feature: 20
      my-old-feature: 80

This is the beginning of the README. Read the rest at the original. Read the full README ↗