Introduction

Feature flagging should not be so complicated.

Mr Flagly is a decentralized feature flagging system written in Rust with bindings for other languages.

It does not depend on third party services or require you to deploy services and databases to manage.

Supported feature flag definition sources:

• URL
• JSON Value
• Environment Variable

Rust usage

Setup your flag service:

use mrflagly::service::{FlagService, FlagServiceOptions};
let flag_service = FlagService::new(FlagServiceOptions {
    finder_type: mrflagly::service::types::FlagFinderType::URL,
    url: "https://path/to/hosted/json/file",
    refresh_interval: 600,
    data: None,
    env_var: None,
})

Then, to check for feature flag:

if flag_service.enabled("feature_x", false /* default value */, Some(HashMap::from([(String::from("user_id"), String::from("123")),])) /* optional context */) {
    // do something
}

Python support

import mrflagly
import json

flag_service = mrflagly.FlagService(data=json.dumps({"feature_x": {"rollout": 100}}))
if flag_service.enabled("feature_x", False, None):
    # do something

JSON format

JSON format for feature flag data:

{
    "my_feature": {
        "rollout": 100
    },
    "my_feature_with_variants": {
        "rollout": 0,
        "variants" {
            "user_id": ["123"],
            "company_id": ["123"]
        }
    }
}