AsyncAPI is an open-source initiative and specification for describing event-driven APIs, the message-based interfaces of event-driven architectures. The project aims to give event-driven systems the same kind of documentation and tooling that REST APIs already have. Its documentation covers the specification, migration guides and tools for documentation, code generation and event management. Because the specification is machine-readable, tools can generate documentation and code from it.
The specification is published in a public GitHub repository under the Apache 2.0 licence. AsyncAPI is a series of LF Projects, LLC, a Delaware series limited liability company that hosts open-source projects, with a contact address in Wilmington, Delaware. Because the specification is open, organisations can adopt it without depending on the description format of a single vendor. It is an open alternative to vendor-specific formats and design platforms for event-driven APIs, whose hosting and data terms vary by vendor.