Here is a list of all concepts with brief descriptions:

[detail level 123]

▼Nfastmm
▼Nbt
RDataSourceLike
▼Ncodecs
RFramer	Splits a byte stream into frames without copying. Must be re-entrant on partial input
RDecoder	Turns one frame into zero or more normalised engine events written to the sink
REncoder	Serialises one outbound command into wire bytes. Returns bytes written; 0 on failure
RSessionLayer	Session-level protocol machinery (FIX Logon/Heartbeat/Resend, SoupBinTCP login, MoldUDP gap requests)
▼Nnet
RConnectionHandler
RWsClientHandler
RDatagramSource
▼Nvenues
RMarketDataFeed
ROrderGateway
RStrategyLike
RKeepsState	Optional state the engine keeps across sessions ([strategy] state_file): `std::string_view state()` returns the bytes to save (valid until the strategy's next hook; the engine copies them at once) and `bool restore(std::string_view)` takes the bytes saved before, false when they are not this strategy's (it then starts fresh)
RClockLike
RMessageLike	Every message: trivially copyable with the EventHeader first
RFixedSizeMessage
RBookView