# reactive-streams/reactive-streams-jvm

Reactive Streams Specification for the JVM

Repository: https://github.com/reactive-streams/reactive-streams-jvm
Canonical: https://ross.abutalabs.com/products/reactive-streams-jvm
Homepage: http://www.reactive-streams.org/
Language: Java
License: MIT-0
License Family: permissive
Last push: 2024-03-13T03:40:25+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4569, "days_push": 903, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4879, forks 531 (observed 2026-08-28T04:09:01.767832+00:00)

## What it is
The Reactive Streams specification for the JVM, defining a minimal set of interfaces (Publisher, Subscriber, Subscription, Processor) for asynchronous stream processing with non-blocking backpressure. It includes a Technology Compatibility Kit (TCK) for verifying that implementations conform to the specification.

## Use cases
- implement a reactive stream library that interoperates with other JVM stream libraries
- verify my stream implementation handles backpressure correctly
- understand the reactive streams specification rules
- test my publisher and subscriber against a conformance suite
- build asynchronous data pipelines without overwhelming consumers
- migrate between reactive libraries using the java.util.concurrent.Flow adapter

## When to choose
- you are building or validating a reactive stream implementation on the JVM
- you need a standard interface so different stream libraries can interoperate
- you need a TCK to certify conformance to the Reactive Streams spec

## When to avoid
- you want a full reactive programming library with operators like map and filter - use Project Reactor, RxJava, or Akka Streams instead
- you need end-user stream processing tools rather than a specification and interfaces
- you are not working on the JVM or a Flow-compatible environment

## Facets
- artifact type: library
- maturity: stable
- function: streaming, concurrency, testing
- domain: developer-tools, microservices
- platform: jvm
- tags: reactive-streams, backpressure, specification, tck, asynchronous, flow-api, real-time

## Member repositories
- reactive-streams/reactive-streams-jvm (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:01.767832+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 2026-08-29T18:18:17.053796+00:00, confidence not recorded.
  - readme: https://github.com/reactive-streams/reactive-streams-jvm (fetched 2026-08-28T04:09:01.767832+00:00, sha 11c954ccf174)
  - homepage: http://www.reactive-streams.org/ (fetched 2026-08-29T09:00:41.049391+00:00, sha a6e2bb7dcf76)
  - site_page: http://www.reactive-streams.org/reactive-streams-1.0.4-javadoc (fetched 2026-08-29T09:00:41.052320+00:00, sha beab3eec4ff1)
- Data as of 2026-08-30T08:39:29.467469+00:00.