@letskomplai/gated

A simple, functional feature flagging library for Node.js. It is designed to solve the 80% use case of having feature toggles on Subjects (users, teams etc). While there are many feature flagging platforms, they are overkill + add complexity of deploying a separate service. Gated is a simple, light-weight alternative that can be used to manage feature flags in your application, saving data in your DB.

Installation

npm install @letskomplai/gated
# or
yarn add @letskomplai/gated
# or
pnpm add @letskomplai/gated

Usage

Configuration

First, configure the library with a data adapter. Gated provides a simple in-memory adapter and a Prisma adapter out of the box.

import { configure, MemoryAdapter } from '@letskomplai/gated';

configure({
  adapter: new MemoryAdapter(),
});

Creating a Flag

import { createFlag } from '@letskomplai/gated';

await createFlag({
  key: 'new-feature',
  description: 'Enable the new experimental feature',
});

Checking for Access

Check if a feature is enabled for a specific subject (e.g., a user).

import { isEnabled } from '@letskomplai/gated';

const subject = { id: 'user-123', attributes: { company: 'acme' } };

if (await isEnabled('new-feature', subject)) {
  // Show the new feature
} else {
  // Show the old feature
}

Granting and Revoking Access

You can grant and revoke access to features for specific subjects.

import { grantAccess, revokeAccess } from '@letskomplai/gated';

const subject = { id: 'user-123' };

// Grant access
await grantAccess('new-feature', subject);

// Revoke access
await revokeAccess('new-feature', subject);

Adapters

• MemoryAdapter: A simple in-memory adapter for testing and development. Data is not persisted.

• PrismaAdapter: An adapter for using a Prisma-compatible database as a backend. To use it, you need to add the required models to your schema.prisma file.

  1. Update your schema.prisma

  Copy the models from the prisma/schema.prisma file in this repository into your own prisma/schema.prisma file. You can find the file here.

  2. Run Prisma migrations

  After updating your schema, run the migrate command to update your database:

  npx prisma migrate dev --name add_gated_models

  3. Configure Gated with the PrismaAdapter

  Finally, instantiate the PrismaAdapter with your Prisma client and pass it to the configure function.

  import { configure, PrismaAdapter } from '@letskomplai/gated';
  import { PrismaClient } from '@prisma/client';
  
  const prisma = new PrismaClient();
  
  configure({
    adapter: new PrismaAdapter(prisma),
  });

Development

• Build: npm run build
• Run tests: npm test
• Lint: npm run lint
• Format: npm run format