aces

ACES

Action · Command · Event · Side-effect · State.

An event-sourced engine whose whole business logic is three pure functions, and everything else (I/O, sync, UI) is swappable around them. Runs isomorphically on a client or a server: change the processors, keep the logic.

The one shape

A machine is a pure object:

machine = {
  initial,            // starting state
  decide(s, action),  // -> events[]   (the only validity judge)
  evolve(s, event),   // -> state      (pure left-fold)
  react(s, event),    // -> effects[]  (asks for I/O, never does it)
  resolve(s, uri),    // -> value      (address any morsel of state)
  render(s),          // -> ascii
}

• decide is the only place an action is judged worthy of becoming a fact. Reject by returning [] (or a Rejected fact).
• evolve is a pure fold. Same log => same state, always. No clock, no random, no I/O.
• react asks for effects; the runtime runs them behind injected processors and feeds results back in as events.
• The event log is truth; state is a cache you can throw away and rebuild with replay(log).

Files

file	what
core.js	the runtime (decide/evolve/react, log, replay, ingest)
calculator.js	archetype: a TI-8x, eager expression + precedence
store.js	archetype: a corner shop (cart/inventory/checkout)
ui.js, store-ui.js	ascii component kits (atoms -> screen)
world.js	multi-instance URI addressing (aces://user/kind/id/field)
deps.js	controlled dependency world (Point-Free style, unimplemented)
sync.js	InstantDB-shaped sync: in-memory + live-admin adapters
pear.js	Holepunch/Pear (hypercore) sync adapter
multisync.js	fan writes to many backends w/ timeouts; dedup reads
mesh.js	wire a runtime to a sync backend (publish out, ingest in)
platform.js	runtime diagnostic: node/bun/worker/durable/rn/web
cli.js	the thin harness: send actions, observe state
test.js, test-net.js	proofs (replay, effect-crash, convergence)

Run

cd aces
node cli.js                 # interactive calculator
node cli.js 2 + 3 '*' 4 =   # batch
node test.js                # core proofs
node test-net.js            # multi-backend sync proofs
node sync-demo.js           # two nodes, one bus, live convergence

House style

Source lines kept <= ~50 columns so they fit a phone preview pane. Deep nesting is treated as a design smell — flatten or extract rather than widen.

Prototype, 2026-07-06.