OpenAPI Specification, explained
Formerly known as Swagger, OpenAPI is maintained by the OpenAPI Initiative under the Linux Foundation. One OpenAPI document can drive interactive documentation, client SDK generation, mock servers, request validation and contract tests.
Comparing two OpenAPI documents, an OpenAPI diff, is a common way to detect structural breaking changes in CI. Its limitation is that it only knows what the document says, not what the implementation actually does.
Related terms
- REST API: A REST API is an HTTP API organised around resources identified by URLs and manipulated with standard methods such as GET, POST, PUT, PATCH and DELETE.
- Breaking change: A breaking change is a change to an API that causes a correctly written client, which worked before, to fail or behave differently without modifying its code.
- Contract testing: Contract testing verifies that an API provider and its consumers agree on the requests and responses they exchange, so either side can change without silently breaking the other.