Feature flags & config

Feature flags and config, without the SaaS.

Pennant serves feature flags and runtime config to your apps over a fast API, with instant updates and per-environment targeting.

Read the documentation →$ pennant serve
Pennant Feature·Instant flag updates·Per-environment·Targeting rules·REST API

Capabilities

Flags & config

Boolean flags, numbers, and JSON config live in one place and change without a deploy.

Instant updates

Clients hold a streaming connection, so a flag flip reaches every instance within a second.

Targeting rules

Roll out by percentage, environment, or attributes — the same flag can differ per audience.

Flip a flag in one call.

Define a flag, evaluate it from your app over HTTP.

  1. 1Start Pennant on any host.
  2. 2Create a flag with a rollout rule.
  3. 3Evaluate it from your app over the API.
# start the server $ pennant serve --data ./flags # create a flag at 25% $ curl -X PUT /v1/flags/new-ui \ -d '{"rollout":25}' # evaluate for a user $ curl '/v1/eval/new-ui?user=42'