Message bus

Deterministic, single-threaded publish and subscribe.

Topics

Dot-separated segments such as data.quotes.ABC. A pattern may use * for exactly one segment and a final > for one or more remaining segments.

Delivery

A message reaches every matching subscriber in subscription order. Anything a handler publishes is queued and delivered after the current message has reached every subscriber. Each message gets the next sequence number when it is delivered.

Delivery log and digest

An optional delivery log records every sequence number, topic and subscriber. Its digest is a 64-bit FNV-1a hash for comparing runs; it is not a cryptographic hash and is not tamper evidence.