# asyncapi/spec

The AsyncAPI specification allows you to create machine-readable definitions of your asynchronous APIs.

Repository: https://github.com/asyncapi/spec
Canonical: https://ross.abutalabs.com/products/asyncapi-spec
Homepage: https://www.asyncapi.com
Language: JavaScript
License: Apache-2.0
License Family: permissive
Topics: asyncapi, reactive, specification, websockets, amqp, mqtt, stomp, kafka
Last push: 2026-08-11T17:58:42+00:00

## Health v2 (maintenance only)
Score: 76/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 97, release rhythm 36, longevity 100
- inputs: {"age_days": 3575, "days_push": 22, "days_rel": 214, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5291, forks 383 (observed 2026-08-28T04:09:15.140510+00:00)

## What it is
The AsyncAPI specification is an open, machine-readable standard for defining asynchronous and event-driven APIs, analogous to OpenAPI for REST APIs. This repository hosts the specification document itself, versioned releases, and examples, under the Linux Foundation.

## Use cases
- define machine-readable contracts for event-driven APIs
- generate documentation for Kafka or RabbitMQ message-driven microservices
- describe WebSocket, MQTT, or AMQP APIs in a standard format
- standardize async API definitions across teams like OpenAPI does for REST
- document event schemas for message brokers
- learn how to write AsyncAPI specification documents

## When to choose
- you build event-driven or message-based architectures and need standardized API contracts
- you want tooling ecosystem support for code generation and docs from async API definitions
- you need a vendor-neutral, language-agnostic specification backed by the Linux Foundation

## When to avoid
- you only build synchronous REST APIs - OpenAPI is the better fit
- you need a runnable tool or library rather than the specification document itself
- you need JSON Schema validation files, which live in the separate spec-json-schemas repo

## Facets
- artifact type: learning-resource
- maturity: stable
- function: api-framework, documentation, api-documentation, sdk
- domain: apis, documentation, developer-tools, microservices
- platform: cross-platform, python, jvm
- tags: asyncapi, openapi-alternative, event-driven-architecture, api-specification, kafka, mqtt, amqp, websockets, machine-readable-contracts, linux-foundation, messaging, nodejs

## Member repositories
- asyncapi/spec (main) score 76

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:15.140510+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 2026-08-29T17:59:12.473336+00:00, confidence not recorded.
  - readme: https://github.com/asyncapi/spec (fetched 2026-08-28T04:09:15.140510+00:00, sha e6d51171a929)
  - homepage: https://www.asyncapi.com (fetched 2026-08-29T08:54:23.375758+00:00, sha c3844b0451f6)
  - site_page: https://www.asyncapi.com/docs (fetched 2026-08-29T08:54:23.385288+00:00, sha 3d4b76ea8e4e)
  - site_page: https://www.asyncapi.com/about (fetched 2026-08-29T08:54:23.387134+00:00, sha 5d037d13cc1e)
- Data as of 2026-08-30T08:39:29.467469+00:00.