eBay recently announced that it adopted AsyncAPI for its external asynchronous API contracts. In March 2021, eBay launched its first AsyncAPI-based contracts for its new business event notification capabilities.
Late last year, eBay initiated work on a new event notification platform designed to meet current and future demands for asynchronous communication to API partners. It found AsyncAPI "extremely helpful because of the ease of use that results from the delineation of channels, protocols, and bindings, separation of concerns between publish and subscribe, and separation of protocol-specific and application-specific headers."
eBay's Shekhar Banerjee comments about the company's requirements:
Aside from the usual considerations of scale, delivery guarantees, monitoring, playback, and recovery, the new platform was also designed for data security, Elliptic Curve Cryptography-based message integrity verification, and support for multiple protocols and payload schema versions. Some of the advanced features also include multi-tenancy with isolation guarantees between different "tenants" of this system and internally separating use-case-specific concerns from core platform concerns.
One of the critical AsyncAPI features that eBay's team has found particularly useful is a clean separation between channels, operations, and servers. A channel represents an event stream, an operation describes a publish or subscribe process, and a server facilitates the message transfer (i.e., the message bus). This separation allows a complete representation of producers, consumers, and message schemas, resulting in a standardized model of a message-driven ecosystem.
Also, Banerjee notes that since AsyncAPI is compatible with the OpenAPI Specification, it allows re-use of schema definitions from existing models, which leads to a short adoption cycle for organizations that have already standardized on the OpenAPI Specification.
AsyncAPI is an open specification meant to be an industry standard for defining asynchronous APIs. It helps unify documentation automation and code generation and manages, testing, and monitoring asynchronous APIs. The specification provides a language for describing event-driven systems' interface regardless of the underlying technology and supports event-driven architecture's complete development cycle.
The Linux foundations announced this March that it would host the AsyncAPI Initiative, providing a forum where individuals and organizations can advance AsyncAPI and nurture collaboration.