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General Internet Engineering Task Force well-known API This document defines the "api-catalog" well-known URI. It is intended to facilitate discovery of the APIs published by a Web host.

Introduction A Web host may publish Application Programming Interfaces (APIs) to encourage requests for interaction from external parties. Such APIs must be discovered before they may be used - i.e., the external party needs to know what APIs a given Web host exposes, including their purpose, any constraints to use, and the endpoints to interact with the APIs. To faciliate discovery of this information, this document proposes a well-known URI, 'api-catalog', as a location where a Web host's API endpoints are listed and described.

Goals and non-goals The primary goal is to facilitate the discovery of both a Web Host's public API endpoints, and metadata that informs the potential API client of the purpose of each API and any constraints around usage. Non-goals: this document does not mandate paths for API endpoints. i.e., it is not mandating that my_example_api should be available at example.com/.well-known/api-catalog/my_example_api (although it is not forbidden to do so).

Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

Using the 'api-catalog' well-known URI The api-catalog well-known URI is intended for HTTP(S) servers that publish APIs and wish to facilitate their discovery. The api-catalog URI SHALL follow the path-prefix for "well-known locations" defined in , namely /.well-known/ : i.e., example.com/.well-known/api-catalog A Web host (example.com) supporting this URI SHALL resolve an HTTP(S) GET request to /.well-known/api-catalog with a list of public APIs. Web hosts SHOULD utilise existing formats to list their APIs, for example or .

IANA Considerations This specification registers the "host-meta" well-known URI in the Well-Known URI Registry as defined by . URI suffix: api-catalog Specification document(s): draft-smith-api-catalog-00 Related information: The "api-catalog" documents obtained from the same host using the HTTP and HTTPS protocols (using default ports) MUST be identical.

Security Considerations TBD

References Normative References Informative References In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. stateless apis-json

Appendix 1 TODO, add examples in HAL and apisJson

Acknowledgements TODO