Feature flags
without the $50K bill
FeatureSignals is an open-source feature management platform with A/B experimentation, real-time updates, and SDKs for every stack. Self-hosted on your infrastructure.
# Start in under 5 minutes
git clone https://github.com/dinesh-g1/featuresignals
cd featuresignals
docker compose up -d
# Evaluate flags from any language
import featuresignals from '@featuresignals/node';
const client = featuresignals.init('sdk-key', { envKey: 'production' });
client.boolVariation('new-checkout', user, false);Why FeatureSignals?
Everything your engineering team needs. No vendor lock-in.
100% Free & Open Source
Apache-2.0 licensed. No per-seat pricing. No per-MAU charges. Self-host on a $10/month VPS.
A/B Experimentation
Built-in variant assignment with consistent hashing, weighted splits, and impression tracking.
Real-Time Updates
SSE streaming pushes flag changes to SDKs instantly. Sub-10ms local evaluation.
SDKs for Every Stack
Go, Node.js, Python, Java, React. All with OpenFeature providers for zero vendor lock-in.
Enterprise Ready
RBAC, audit logs, approval workflows, webhooks, kill switches, and mutual exclusion groups.
Deploy Anywhere
Docker Compose, VPS, Kubernetes. Plus a relay proxy for edge deployments. Single Go binary.
Built for developers, by developers
Everything you need to ship features safely. Nothing you don't.
5 Flag Types
Boolean, string, number, JSON, A/B
5 SDKs
Go, Node.js, Python, Java, React
13 Targeting Operators
eq, neq, contains, in, regex, gt...
Percentage Rollouts
Consistent hashing, 0.01% granularity
Mutual Exclusion
Run safe, non-overlapping experiments
Kill Switch
Emergency disable in one click
Relay Proxy
Edge caching, low-latency evaluation
Stale Flag Scanner
CI tool to find unused flags in code
Ready to ship faster?
Get started in under 5 minutes with Docker Compose.