Introduction

Adonis Flick is a typed, driver-based feature-flag system for AdonisJS. Define a feature once, then resolve it for any user, tenant, or request, with full TypeScript inference and a pluggable cache.

import { BaseFeature } from "@foadonis/flick";
import User from "#models/user";

export default class NewCheckoutFeature extends BaseFeature<User> {
  async resolve(user: User) {
    if (user.isAdmin) return true;

    return Math.random() > 0.5;
  }
}

import router from "@adonisjs/core/services/router";
import flick from "@foadonis/flick/services/main";

router.get("/checkout", async ({ auth, view }) => {
  const user = auth.getUserOrFail();

  return flick.for(user).match("new_checkout", {
    active: () => view.render("checkout/new"),
    inactive: () => view.render("checkout/legacy"),
  });
});

match runs the active callback when the feature resolves to a truthy value, and inactive otherwise. The full resolution API (isActive, isInactive, value, values, match, and the allActive / someActive batch helpers) is covered in Resolving Features.

What are feature flags?

Feature flags let you decouple deploying code from releasing functionality. Instead of shipping a new feature to everyone the moment it's merged, you wrap it in a flag and decide, at runtime, who sees it. Common uses include gradual rollouts, beta-tester opt-ins, A/B tests, and kill switches for risky code paths.

Why a dedicated package?

A boolean in your .env file is the simplest feature flag, and it falls over fast. Environment variables are global (everyone sees the same value), require a restart to change, and can only express "on" or "off". Flick lets you scope a flag to any value you choose (a user, an organization, a request) and return any value from it (a boolean, a variant string, a config object).

Features

• Typed feature names: Auto-complete and type-check feature names from a generated registry
• Variant returns: Features can return any value, not just booleans
• Scope-aware: Resolve a flag per user, tenant, request, or any object you decide
• Edge support: Custom edge tags for using features flags in your views
• Driver-based caching: Memory and Redis drivers ship out of the box
• Pluggable drivers: Implement the driver contract to back flick with anything

Next steps

Ready to get started? Head over to the Getting Started guide to install Flick and ship your first flag in minutes.