# elixir-lang/gen_stage

Producer and consumer actors with back-pressure for Elixir

Repository: https://github.com/elixir-lang/gen_stage
Canonical: https://ross.abutalabs.com/products/gen_stage
Homepage: http://hexdocs.pm/gen_stage
Language: Elixir
License Family: other
Last push: 2026-08-05T09:55:42+00:00

## Health v2 (maintenance only)
Score: 75/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 96, release rhythm 35, longevity 100
- inputs: {"age_days": 4025, "days_push": 28, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1590, forks 199 (observed 2026-08-28T04:05:08.537280+00:00)

## What it is
GenStage is an Elixir specification and behaviour for exchanging events between producer and consumer stages with built-in back-pressure. It also provides ConsumerSupervisor for starting a child process per event, and underpins the Flow and Broadway data-processing libraries.

## Use cases
- build back-pressured event pipelines in Elixir
- consume events from queues like SQS or RabbitMQ concurrently
- implement rate limiting in a processing pipeline
- replace GenEvent with a concurrent, buffered event manager
- run multi-stage producer-consumer data processing

## When to choose
- you need demand-driven event flow with back-pressure in Elixir
- you're building pipelines on top of Flow or Broadway
- you want per-event supervised consumption

## When to avoid
- you're not working in Elixir/Erlang
- you need a full data-ingestion framework rather than a low-level behaviour (consider Broadway)
- you need map-reduce/windowed computation (consider Flow)

## Facets
- artifact type: library
- maturity: stable
- function: concurrency, message-queue, streaming, rate-limiting, workflow-automation
- domain: microservices, backend
- platform: elixir, jvm, windows
- tags: back-pressure, producer-consumer, event-pipeline, genstage, consumer-supervisor, data-engineering, real-time, linux, macos

## Member repositories
- elixir-lang/gen_stage (main) score 75

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:08.537280+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 2026-08-30T03:54:47.126514+00:00, confidence not recorded.
  - readme: https://github.com/elixir-lang/gen_stage (fetched 2026-08-28T04:05:08.537280+00:00, sha b0750c88f661)
  - homepage: http://hexdocs.pm/gen_stage (fetched 2026-08-29T11:25:23.943946+00:00, sha 3b285ab5c597)
- Data as of 2026-08-30T08:39:29.467469+00:00.