CoAP RFCs

CoAP, Constrained Application Protocol, is a communications protocol intended for ‘constrained’ devices, such as those with less resources or power. It is similar to HTTP in scope.

The Original RFC

• RFC 7252 — The Constrained Application Protocol (CoAP) (June 2014)

Further RFCs

• RFC 7641 — Observing Resources in the Constrained Application Protocol (September 2015)
• RFC 7959 — Block-Wise Transfers in the Constrained Application Protocol (August 2016)
• RFC 8232 — Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE (September 2017)
• RFC 8323 — CoAP over TCP, TLS, and WebSockets (February 2018)
• RFC 8613 — Object Security for Constrained RESTful Environments (July 2019)

CoAP Parameter Numbers

IANA also maintains the lists of CoAP parameter numbers, including the method codes, response codes, option numbers, and Content-Format numbers.