# openflagr/flagr

Flagr is a feature flagging, A/B testing and dynamic configuration microservice

Repository: https://github.com/openflagr/flagr
Canonical: https://ross.abutalabs.com/products/flagr
Homepage: https://openflagr.github.io/flagr
Language: Go
License: Apache-2.0
License Family: permissive
Topics: feature-flags, ab-testing, golang, dynamic-configuration, swagger, feature-toggles
Last push: 2026-08-20T08:46:39+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 98, longevity 100
- inputs: {"age_days": 3256, "days_push": 13, "days_rel": 13, "gap_med": 25, "n_releases_24m": 8}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2606, forks 204 (observed 2026-08-28T04:07:04.082942+00:00)

## What it is
Flagr is an open-source Go microservice for feature flagging, A/B testing, and dynamic configuration, built around a single evaluation API that returns a variant and optional JSON attachment for a given entity. It supports SQLite, MySQL, and Postgres backends, an eval-only sidecar mode fed from JSON in Git, and a web UI for managing flags.

## Use cases
- decouple deployment from release with feature flags and kill switches
- run A/B tests with sticky variant assignment per user
- change runtime configuration without redeploying the app
- self-host a feature flag service with a web UI and REST API
- run an eval-only sidecar with flags defined in a Git-tracked JSON file
- roll out features gradually to targeted audience segments

## When to choose
- you want a self-hosted, open-source alternative to LaunchDarkly or similar SaaS flag platforms
- you need feature flags, A/B testing, and dynamic config from one service
- you want sticky per-entity variant assignment without a per-user state store
- your stack is Go or you prefer a lightweight Docker-deployable microservice

## When to avoid
- you need a mature SDK ecosystem across many languages rather than a plain HTTP API
- you require advanced experimentation analytics and statistical significance reporting
- you want a fully managed hosted solution with no operational overhead

## Facets
- artifact type: service
- maturity: active
- function: feature-flags, api-framework, http-server, configuration-management
- domain: web-development, backend, developer-tools, apis, self-hosted
- platform: windows, self-hosted, go
- tags: ab-testing, dynamic-configuration, kill-switch, feature-toggles, experimentation, microservice, swagger, gitops, linux, macos, docker, web-server

## Member repositories
- openflagr/flagr (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:04.082942+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:21:00.625468+00:00, confidence not recorded.
  - readme: https://github.com/openflagr/flagr (fetched 2026-08-28T04:07:04.082942+00:00, sha 2f3204a759b5)
  - homepage: https://openflagr.github.io/flagr (fetched 2026-08-29T10:03:54.624167+00:00, sha a2f00be0e4c7)
- Data as of 2026-08-30T08:39:29.467469+00:00.