libcoap  4.3.0rc3
Modules
Here is a list of all modules:
 ASN.1 Support (Internal)CoAP ASN.1 Structures, Enums and Functions that are not exposed to applications
 Application I/O HandlingAPI functions for Application Input / Output
 Application I/O Handling (Internal)Internal API functions for Application Input / Output
 Asynchronous MessagingAPI functions for Async "separate" messages
 Asynchronous Messaging (Internal)CoAP Async Structures, Enums and Functions that are not exposed to applications
 Block (Internal)Structures, Enums and Functions that are not exposed to applications
 Block TransferAPI functions for handling PDUs using CoAP BLOCK options
 Cache SupportAPI functions for CoAP Caching
 Cache Support (Internal)CoAP Cache Structures, Enums and Functions that are not exposed to applications
 Clock HandlingDefault implementation of internal clock
 Context HandlingAPI functions for handling PDUs using CoAP Contexts
 Context Handling (Internal)CoAP Context Structures, Enums and Functions that are not exposed to applications
 DTLS SupportAPI functions for interfacing with DTLS libraries
 DTLS Support (Internal)CoAP DTLS Structures, Enums and Functions that are not exposed to applications
 Encode / Decode APIAPI functions for endoding/decoding CoAP options
 Event APIAPI functions for event delivery from lower-layer library functions
 Logging SupportAPI functions for logging support
 Observe Subscription (Internal)CoAP Observe Subscription Structures, Enums and Functions that are not exposed to applications
 Option FiltersAPI functions for access option filters
 PDUAPI functions for PDUs
 PDU (Internal)CoAP PDU Structures, Enums and Functions that are not exposed to applications
 Pseudo Random NumbersAPI functions for gerating pseudo random numbers
 Rate ControlThe transmission parameters for CoAP rate control ("Congestion Control" in stream-oriented protocols) are defined in https://tools.ietf.org/html/rfc7252#section-4.8
 Resource ConfiguratonAPI functions for setting up resources
 Resource ObservationAPI functions for interfacing with the observe handling (RFC7641)
 Resources (Internal)Structures, Enums and Functions that are not exposed to applications
 SessionsAPI functions for CoAP Sessions
 Sessions (Internal)CoAP Session Structures, Enums and Functions that are not exposed to applications
 String handling supportAPI functions for handling strings and binary data
 TCP Support (Internal)CoAP TCP Structures, Enums and Functions that are not exposed to applications
 URI Parsing FunctionsCoAP PDUs contain normalized URIs with their path and query split into multiple segments