Lightweight, open-source feature flags for developers and small teams.
μflags is intentionally simple: boolean flags, fixed environments (DEV, QA, PROD), local SDK evaluation, and a stack you can host without a DevOps department.
Feature flags that are easy to understand, easy to host, and inexpensive to operate.
We are not building LaunchDarkly. If you need experimentation, percentage rollouts, or complex targeting, this is not the right tool — and that is by design.
Most feature-flag products optimize for enterprise scale. μflags optimizes for:
- Clarity — boolean on/off, per environment. No mystery evaluation rules.
- Low cost — you host the API and database; we keep the surface area small.
- Developer experience — typed SDK, clean dashboard, boring and reliable architecture.
- Ownership — your flag data stays on your infrastructure.
| Piece | Role |
|---|---|
| Dashboard | Manage projects, environments, and flags |
| Backend | NestJS API + PostgreSQL (you run it; we publish a Docker image) |
| SDK | Fetch config from your backend and evaluate flags locally in your apps |
Hosting model: hosted dashboard + customer-hosted API/database. Details: docs/hosting.md.
- Boolean feature flags
- Fixed environments: DEV, QA, PROD (PROD protected)
- Projects, members, and roles
- Local SDK evaluation
- Notifications and audit log
- A/B testing, experimentation, analytics
- Percentage rollouts, user targeting, segments
- Billing or enterprise SSO
- Multi-region replication or real-time streaming
- Complex flag types
- Custom environments beyond DEV / QA / PROD
| Area | Stack |
|---|---|
| Monorepo | Nx |
| Dashboard | Next.js, TypeScript, Tailwind, shadcn/ui |
| Backend | NestJS, Prisma, PostgreSQL, @nestjs/cqrs |
| Docs | Nextra |
| Testing | Vitest, Playwright |
Architecture: a modular monolith with NestJS CQRS and in-process domain events — no microservices, Kafka, or event sourcing.
apps/
web/
backend/
docs/
mobile/
packages/
sdk-js/
sdk-react/
schemas/
shared/
ui/
eslint-config/
tsconfig/
Nx workspace with a Next.js dashboard scaffold in apps/web. Other apps are still placeholders; packages have minimal stubs (package.json, README, entrypoints).
Early stage. The product vision and domain model are defined; implementation is underway.
See docs/milestones.md for the roadmap and docs/domain.md for the domain model.
MIT (planned). Contributions and feedback welcome once the repo is ready for them.