payload-feature-flags/CLAUDE.md

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

This is a Payload CMS v3 plugin for feature flags (@xtr-dev/payload-feature-flags). The plugin enables feature toggles, A/B testing, and gradual rollouts through a dedicated collection and server-side hooks.

Key Commands

Development

• pnpm dev - Start Next.js dev server with Payload CMS admin panel
• pnpm dev:payload - Run Payload CLI commands for development
• pnpm dev:generate-types - Generate TypeScript types from Payload config
• pnpm dev:generate-importmap - Generate import map for admin panel

Building

• pnpm build - Full production build (copies files, builds types, compiles with SWC)
• pnpm build:types - Generate TypeScript declarations only
• pnpm build:swc - Compile TypeScript to JavaScript using SWC
• pnpm clean - Remove dist directory and build artifacts
• pnpm copyfiles - Copy non-TS assets to dist

Testing & Quality

• pnpm test - Run all tests (integration + e2e)
• pnpm test:int - Run integration tests with Vitest
• pnpm test:e2e - Run end-to-end tests with Playwright
• pnpm lint - Run ESLint
• pnpm lint:fix - Run ESLint with auto-fix

Publishing

• pnpm prepublishOnly - Clean and build before publishing (runs automatically)

Architecture

Plugin Structure

The plugin follows Payload's plugin architecture with multiple exports:

• Main export (src/index.ts): Core plugin configuration function
• RSC export (src/exports/rsc.ts): Server-side hooks for React Server Components
• Client export (src/exports/client.ts): Client-side components (currently placeholder)

Core Components

Plugin Configuration (src/index.ts)

• PayloadFeatureFlagsConfig: Main configuration type
• payloadFeatureFlags(): Plugin factory function that creates a Payload collection and optional API endpoints
• Collection overrides support for full customization
• Feature toggles for rollouts, variants, and API endpoints

Server Hooks (src/hooks/server.ts)

• getFeatureFlag(): Fetch individual flag data
• isFeatureEnabled(): Simple boolean check
• getAllFeatureFlags(): Get all active flags
• isUserInRollout(): Check percentage-based rollouts with consistent hashing
• getUserVariant(): A/B testing variant selection
• getFeatureFlagsByTag(): Query flags by tags

API Endpoints (src/endpoints/customEndpointHandler.ts)

• GET /api/feature-flags - List all active feature flags
• GET /api/feature-flags/:flag - Get specific flag data
• Only created when enableApi: true

Collection Schema

The plugin creates a feature flags collection with these key fields:

• name (unique): Flag identifier
• enabled: On/off toggle
• rolloutPercentage: 0-100% rollout control
• variants: Array for A/B testing with weights
• tags: Organization and filtering
• metadata: Additional JSON data

Development Environment

• Uses MongoDB Memory Server for testing
• Next.js for admin panel development
• SWC for fast compilation
• Vitest for integration testing
• Playwright for E2E testing

Export Strategy

The plugin publishes with different entry points:

• Development: Points to TypeScript sources (src/)
• Production: Points to compiled JavaScript (dist/)
• Supports both CommonJS and ESM through package.json exports

Important Notes

Plugin Integration

The plugin integrates with Payload by:

1. Creating a feature flags collection with configurable slug and fields
2. Adding optional REST API endpoints
3. Providing server-side hooks that work with any collection slug
4. Supporting full collection customization through collectionOverrides

Security Considerations

• REST API endpoints are disabled by default (enableApi: false)
• Server-side hooks are the preferred method for accessing feature flags
• Collection access can be restricted through collectionOverrides.access

Testing Setup

The development configuration (dev/payload.config.ts) includes:

• MongoDB Memory Server for isolated testing
• Test collections (posts, media)
• Example plugin configuration with collection overrides
• Seeding functionality for development data