🚀 FlagShip - Feature Flag Management Platform

A full-stack feature flag management system with React frontend and Spring Boot + MySQL backend.
Developers can create, update, and manage feature flags, then evaluate them via an API that returns a boolean value using sticky deterministic bucketing.

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✨ Features

• 🔑 User authentication (signup/login)
• 🏷️ CRUD operations for feature flags
• ⚙️ Configurable attributes: name, description, rollout percentage, allowed countries
• 🧮 Deterministic rollout evaluation (sticky bucketing)
• 🌍 Country-based targeting
• 🔐 API key authentication for external apps
• 📡 REST API returns true/false on feature evaluation
• 📊 Success tracking & analytics (success ratio / lift between feature and control groups)

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🛠️ Tech Stack

• Frontend: React
• Backend: Spring Boot
• Database: MySQL

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📦 Installation & Setup

Prerequisites

• Java 17+
• Node.js 18+
• MySQL running locally or on cloud

Backend (Spring Boot)

cd backend
./mvnw spring-boot:run

⚠️ The frontend is bundled and served from the Spring Boot app. It does not need to be run seperately

Frontend (React)

cd frontend
npm install
npm start

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📖 API Usage

Authentication

Each user is issued an API Key after login.
Pass this key in the request header when evaluating a feature flag.

Evaluate Feature Flag

Endpoint:
GET /api/evaluate/{id}

Headers:
X-API-Key: your-api-key

Request example:
GET /api/evaluate/550e8400-e29b-41d4-a716-446655440000?userId=user123&userCountry=IN

Response:
true

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Track Success Event

To record when a user action is successful (used later for computing the success ratio / lift):

Endpoint:
POST /api/success/{id}

Headers:
X-API-Key: your-api-key

Query Parameters:

• userId – ID of the user triggering the success

Request example:
POST /api/success/550e8400-e29b-41d4-a716-446655440000?userId=user123

Response:
200 OK

This increments the success count for the user’s assigned group (feature vs control). The frontend dashboard uses these counts to calculate the success ratio (lift) of the feature against the control group.

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🧮 How Sticky Bucketing Works

1. The system hashes userId + featureId + salt.
2. Hash is mapped into a bucket 0–99.
3. If bucket < rollout percentage → feature enabled.
4. Country filters and whitelist rules override rollout logic.

This ensures the same user consistently receives the same result.

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📷 Screenshots

Login Page

Dashboard

Creating new Feature Flag