The kind of systems we build.

// project.json — custom Nx executor
"serve": {
  "executor": "@acme/nest-dx:dev",
  "options": {
    "hmr": true,       // 20–100ms swap
    "instances": 2,    // per app
    "gateway": true    // one port
  }
}

// dev gateway server — N instances per
// app, routed by URL prefix
for (const app of apps)
  for (let i = 0; i < app.instances; i++)
    fork('dist/main.js', {
      env: { NEST_SOCK: sock(app, i) },
    });
gateway.use('/orders/*', balance('orders'));
gateway.listen(EXTERNAL_PORT);   // clients
gateway.internal(INTERNAL_PORT); // services

// local queue mirrors production:
// events fan out across instances
@EventPattern('order.created')
async onOrderCreated(@Payload() e) {
  // handled by whichever instance
  // pulls it — exactly like multi-node
}

// raw browser event → semantic signal — no input values, ever
const e = capture(event);
// {
//   kind:  'click',          // pointer · scroll · hover · form
//   role:  'primary_cta',    // what the element means
//   zone:  'pricing',        // where on the page
//   dwellMs: 4200,
//   confidence: 0.92,        // identity x semantic
// }

// encode events with a per-page codec → opaque coded events
// dictionary: { click: 4, hover: 5, scroll: 6, cta: 17 }
const coded = codec.encode(e);
// [4, 17, 9, 1]   ← compact, opaque on the wire
// the taxonomy and scoring never leave the backend.

// a continuous funnel feeds the realtime agent, in order
for await (const coded of funnel) agent.push(coded);
const intent = agent.infer();          // produced from events
if (intent.confidence < 0.4) return hold();   // do not interrupt
if (gate.allow(intent.action, { cooldown }))
  emit(intent.action);   // <250ms — local fallback if slow

// a flow is a dependency graph, not a script
const flow = defineFlow('case-review', {
  trigger: ['event:case.created',     // something happened
            'agent:intake.done',      // another agent finished
            'approval:resumed'],      // a human decided
  steps: [
    step('intake',   agents.intake),
    step('analysis', agents.analysis,   { after: 'intake' }),
    step('comply',   agents.compliance, { after: 'intake' }), // ← parallel
    gate('review',   approvers('ops'),  { after: ['analysis', 'comply'] }),
    step('finalize', agents.finalize,   { after: 'review' }),
  ],
});

// one agent definition · many working entities
const analysis = defineAgent('analysis', {
  resources: [db('cases'), api('records'), docs('policies')],
  // base instructions + context injected per working entity
  instructions: (entity) => inject(BASE, entity),
  input:  CaseRef,        // verified before the agent runs
  output: Findings,       // verified before it propagates
  loop: { until: (o) => o.confidence >= 0.9, max: 5 },
});

// not every step needs a model — code where code wins
step('normalize', transform((rows) => toCanonical(rows)));
step('dedupe',    code((rows) => uniqBy(rows, 'id'),
                       { cache: '24h' }));   // deterministic · cached
// every run is a tree of spans — inspect it, replay it
const run = await flow.run({ entity: case4821 });
run.trace();  // trigger → agents ×2 → approval → finalize ✓