Self-hosted feature flag service. One binary. Zero dependencies. Ship with confidence.
Everything you need to ship features safely, in a single binary your team controls.
In-memory cache serves flags in microseconds. No database queries on the hot path.
One executable, embedded web UI, SQLite built-in. Just run it. No infrastructure needed.
Runs on your infrastructure. Your data never leaves your network. Full control.
Go, Python, Node.js, Java (Spring Boot). Zero external dependencies in each SDK.
Helm chart included. SQLite for dev, PostgreSQL for production HA with pg_notify.
Standard (SQLite) and Enterprise (PostgreSQL HA, SSO, audit export). License-key gated.
Same flag data pushed through three different channels in parallel. Open the admin panel in another tab, toggle a flag, and watch each panel's latency.
| Flag | Status |
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| Flag | Status |
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| Flag | Status |
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Toggle checkout.new-flow
in the admin panel to see this change (driven by the SSE panel):
Simple architecture. No moving parts.
What's coming next. Built incrementally, shipped as updates to the same binary.
Sub-second flag propagation via Server-Sent Events (see demo above)
Beyond boolean — serve config values and A/B variants
Percentage rollouts, user segments, targeting rules
More storage backends. Redis for cross-pod cache sync
Bidirectional streaming for high-throughput environments
Ruby, PHP, .NET, Rust, mobile (iOS/Android)
flagd is built for teams that want feature flags without the SaaS dependency.
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