Closing the push gap
The previous session built the Market Pulse pipeline — five summarisation levels, synthetic tick generation, LLM-powered regime assessment, REST endpoints, arena integration. All of it working. But the push path — the thing that makes it a live trading panel instead of a polling API — was hollow. FsiMarketPushService existed as a standalone POJO with a test double for the broadcaster. No WebSocket endpoint. No CDI wiring. No browser could connect.
The plan called the final task “Minimal UI Panel” and scoped it as Quinoa setup plus a static web component. Reading the decision record (D1: full vertical slice), that didn’t match. D1 says “prove the end-to-end push path works.” A panel that renders HTML but never connects to a WebSocket proves the build tooling, not the architecture.
What was actually missing
The pages-push library is deliberately transport-agnostic. EventBroadcaster distributes events; TopicRegistry manages subscriptions via a trie with colon-separated segments and wildcard matching (market:ticks:*); SessionSender is the escape hatch where the application plugs in its transport. The library doesn’t include a WebSocket endpoint — that’s the application’s job.
So the real work was three pieces the plan didn’t account for:
FsiPushConnectionRegistry implements SessionSender — a ConcurrentHashMap of WebSocket connections, keyed by connection ID. When EventBroadcaster calls send(connectionId, message), the registry finds the right connection and pushes. Simple, but without it, broadcast events have nowhere to go.
FsiPushWebSocket is the Quarkus WebSocket Next endpoint at /ws/push. It handles the pages-push wire protocol: clients send {"op":"listen","id":"1","topics":["market:ticks:*"]}, the endpoint registers them in the TopicRegistry, sends back an ack. On close, it cleans up both registries. The protocol supports wildcard subscriptions — a client listening on market:regime:* gets regime assessments for every instrument without knowing which instruments exist.
The CDI bridge: MarketPulseConfiguration produces FsiMarketPushService backed by EventBroadcaster, and MarketPulseScheduler.onStart() subscribes it to all five level buses. Ticks flow from the scheduler through the pipeline, through the push service, through the broadcaster, through the registry, to the browser.
The ObjectMapper surprise
The first build with push wiring produced background stack traces in the Quarkus test output — tests still passed, but EventBroadcaster was silently failing to serialize PriceTick records. The casehub-pages-push-runtime module provides a @DefaultBean JsonWriter backed by new ObjectMapper() — a bare instance with no JavaTimeModule. Any record with an Instant field (which is every domain type in the pipeline) throws InvalidDefinitionException on serialization.
The fix: override the @DefaultBean with a producer that injects the Quarkus-configured ObjectMapper, which already has all the right modules registered. One line of CDI wiring, but the failure mode was genuinely hard to trace — the exception was thrown inside a bus subscriber callback during scheduled tick generation, with no obvious connection to the push infrastructure.
The panel
With the transport layer working, the panel itself is straightforward TypeScript. A web component that opens a WebSocket, sends a listen for market:ticks:*, market:bars:*, and market:regime:*, then updates a table with live prices, regime badges, and SVG sparklines as events arrive. Quinoa handles the esbuild bundling inside the Maven build — npm install and npm run build happen automatically during quarkus:build.
The whole push path — from synthetic tick generation through five summarisation levels to a browser table cell — runs in a single process. EventStreamBus publishes; bus subscribers fan out to the observation cache, the push service, the channel bridge, and downstream runners. The push service calls EventBroadcaster.broadcast(); the broadcaster serializes to JSON, walks the topic trie for matching connections, and calls SessionSender.send() on each. The data reaches the browser as {"op":"event","topic":"market:ticks:AAPL","payload":{...},"seq":42}.
This is D1 delivered. The minimal panel will get replaced by C5’s dock-workbench composition, but the transport layer, the CDI wiring, and the wire protocol are the real infrastructure — and those carry forward.