echd — Echo on Encore · E3.1
One Bus, Twelve Families
The platform's events, schedules, and jobs ride one owned protocol — twelve families over one braced keyspace behind one versioned wire, so any runtime that speaks it is a peer.
echd speaks in the present tense over a build ladder. Every module, verb, key, and port named on this page is real; the composition into one standing platform is the vision the ladder builds.
The module
docs/echo_mq/specs/emq.commands/README.md · emq.design.mdThe bus is one protocol with a wide surface — commands for streams, schedules, claims, retries, locks, and more. What keeps that surface one thing, rather than an accumulation, is a single organizing rule: every command belongs to exactly one of twelve families, every family writes into one braced keyspace, and the whole speaks behind one versioned wire. This module holds the protocol at that structural level — not what each verb does (that is the next two modules), but how the bus is built so that any runtime can speak it.
Turn the structure and its three facets resolve into one discipline seen from three sides. The twelve families are the taxonomy — the map the command registry sorts every version of the protocol by, from admission through lifecycle. The braced keyspace is the master invariant — one root per queue so a queue's keys share a slot, branded JOB ids gated at the key builder, every Lua key declared, the server's clock on every lease — the rules that once broke the wire and are now hard-pinned. And the wire fence is why the protocol travels: because it is Valkey commands and inline Lua at echomq:3.0.0, a reader written in any language stands in the same consumer group as the BEAM. Structure, invariant, fence — one bus, and anyone can read it.
The protocol, drawn
hover a facetemq:{q}:, so a queue's keys share a hash slot; ids are branded JOB, gated at the key builder; every Lua key is declared, never derived inside the script; and every lease is stamped by the server's clock. These are the rules that once broke the wire — now hard-pinned.echomq:3.0.0 fence — no runtime in the middle. Any runtime with a Valkey client is a first-class peer; the conformance suite proves it, a non-BEAM reader draining the same consumer group as the BEAM.Hover or focus a facet to read it; click to pin. Without scripting, all three read in sequence.
The dives
three moves downThe Twelve Families
Admission to lifecycle — the taxonomy every command sorts into, grouped by a job's life.
D2The Braced Keyspace
One braced root, branded JOB, every Lua key declared, the server's clock — the master invariant.
D3The Wire Fence
echomq:3.0.0 and the polyglot seam — why any runtime that speaks it is a first-class peer.
Doors
the protocol in depthEchoMQ — the protocol, in depth
The keyspace grammar, the Lua inventory, and the conformance suite this module compresses into three moves.
the twelve families, verb by verb — the command registry this taxonomy indexes.
/redis-patternsRedis Patterns, Applied
The pattern judgement beneath the verbs: reliable queues, streams, flow control, declared-key scripts.
why the invariants hold — the same disciplines, taught pattern-first.
References
sources · relatedSources
- Valkey — ProgrammabilityEVALSHA and atomic Lua — the declared-keys discipline the bus pins to every family
- Valkey — Cluster specificationhash tags: why one braced {q} co-locates a queue's keys in a single slot
Related
- EchoMQ — the protocol, in depththe far side of the door — the full keyspace grammar and Lua inventory
- E3 — The Bus — EchoMQ Supersedesthe chapter this module opens
- echd — the course homethe supersession switchboard