Everything you need to manage feature flags

A complete, open-source feature management platform built for engineering teams that value speed, control, and transparency.

Flag Engine

Boolean, string, number, JSON, and A/B flag types. Percentage rollouts with MurmurHash3 consistent hashing. User targeting with 13 operators. Segment-based rules with AND/OR logic.

A/B Experimentation

Built-in variant assignment with weighted splits. Consistent hashing ensures the same user always sees the same variant. Impression tracking API for analytics. Per-environment variant weights.

Mutual Exclusion Groups

Prevent experiment interference by grouping flags that should never be active for the same user simultaneously. The evaluation engine deterministically selects a winner using consistent hashing.

Multi-Environment

Dev, staging, production, and custom environments. Per-environment flag states and targeting rules. Promote configurations between environments. Per-environment API keys.

SDKs for Every Stack

Go, Node.js, Python, Java, and React SDKs. All implement OpenFeature providers for zero vendor lock-in. Local evaluation with zero-latency after init. SSE streaming for real-time updates.

Relay Proxy

A lightweight Go binary that caches flag values at the edge. Reduces latency, provides fault tolerance, and minimizes upstream API load. Syncs via SSE or polling.

Enterprise Governance

Tamper-evident audit logs with before/after diffs. Approval workflows for production changes. RBAC with owner/admin/developer/viewer roles. Per-environment toggle and rule-edit permissions.

Kill Switch & Scheduling

Emergency disable any flag with one click. Schedule flags to auto-enable or auto-disable at specific times. Background scheduler checks every 30 seconds with full audit trail.

Webhooks & Integrations

HTTP webhooks with HMAC-SHA256 signatures. Event filtering by type. Exponential retry with delivery logging. Integrate with Slack, CI/CD pipelines, or any HTTP endpoint.

Stale Flag Scanner

CLI tool that scans your codebase for flag references and reports stale (unused) flags. Integrates with CI/CD via --ci mode (exit code 1 on stale flags found). JSON and table output.

Deploy Anywhere

Docker Compose for quick start. Self-host on Hetzner, DigitalOcean, OVH, Vultr, or any VPS. Kubernetes-ready. Caddy for automatic HTTPS. Single Go binary with zero external dependencies beyond PostgreSQL.

Evaluation Metrics

In-memory counters tracking evaluations per flag, environment, and reason. Dashboard visualization with top-flags bar chart and reason breakdown. Impression tracking for A/B experiments.