canopus

Fully implements the core CoAP standard, ensuring reliable communication for constrained devices as specified in the key features and examples.

Built-in observe/notify functionality allows efficient monitoring of resource changes without polling, demonstrated in the observe example with server.NotifyChange and client.Observe.

Supports secure, encrypted connections using Pre-Shared Key authentication, providing basic security for IoT applications, as shown in the dTLS example with server.HandlePSK.

Can act as a CoAP-to-CoAP or CoAP-to-HTTP proxy, facilitating protocol translation and routing, with clear examples for both proxy types in the README.