@terreno/feature-flags

Feature flags and A/B testing plugin for @terreno/api.

Install

bun add @terreno/feature-flags

Peer dependency: mongoose ^8.0.0 || ^9.0.0. @terreno/api is required at runtime.

Quick start

import {TerrenoApp} from "@terreno/api";
import {AdminApp} from "@terreno/admin-backend";
import {FeatureFlagsApp, featureFlagAdminConfig} from "@terreno/feature-flags";
import {User} from "./models/user";

new TerrenoApp({userModel: User})
  .register(new FeatureFlagsApp({}))
  .register(new AdminApp({models: [featureFlagAdminConfig]}))
  .start();

Authenticated clients load flags from GET /feature-flags/flagConfiguration. Prefer that bulk map over the deprecated GET /feature-flags/evaluate endpoint (responses include Deprecation: true and a Sunset header).

Pass liveUpdates: {socketIoServer: io} to broadcast flag-key changes over Socket.io. Live updates require MongoDB running as a replica set (a single-node replica set is enough).

What's included

• FeatureFlagsApp — TerrenoPlugin for admin CRUD, /flagConfiguration, and /evaluate
• FeatureFlag — Mongoose model for flag documents
• featureFlagAdminConfig — ready-to-use AdminApp model config
• evaluateFlag / evaluateAllFlags — server-side evaluation helpers
• MongoFeatureFlagProvider — OpenFeature server provider
• Optional socket live updates on change streams

Documentation

Full API reference: docs/reference/feature-flags.md

How-to: Add feature flags

License and Contributing

Licensed under the MIT License. See CONTRIBUTING.md for contribution guidelines.