OpenAPI QL: Searching in OpenAPI Service Catalogs

Abstract

An OpenAPI description details the actions exposed by a REST API. Existing query languages (e.g. JSONpath or N1QL for JSON) are not designed for OpenAPI and suffer from several drawbacks the most important of them being that, queries are complicated expressions and users must be familiar with the underlying OpenAPI representation. We introduce OpenPI QL, a query language for OpenAPI service descriptions. OpenAPI QL relies on a model that identifies the features that can be used to query a service description. OpenAPI QL employees SQL syntax and maintains the necessary simplicity of expression (i.e. using properties of REST services in simple SQL statements) regardless of service complexity and ignoring the nested structure of OpenAPI. Although independent from OpenAPI, queries can address the most important features of a service description in a database. The run-time performance of SOWL QL has been assessed experimentally in a database with OpenAPI descriptions of real services. A critical analysis of its performance is also presented along with several query examples.