WorkflowHub implements GA4GH's Tool Registry Service API to facilitate discovery of workflows in an interoperable way.
The root of the API is at https://workflowhub.eu/ga4gh/trs/v2/ So, for example, tools can be found at: https://workflowhub.eu/ga4gh/trs/v2/tools
Documentation on how to use the TRS API can be found here: https://ga4gh.github.io/tool-registry-service-schemas/swagger-ui/?url=../preview/develop/docs/web_deploy/swagger.json.
Details of the current implementation, such as the version of the specification implemented, and associated documentation can be found here: https://workflowhub.eu/ga4gh/trs/v2/service-info