Runtime — the LiveEngine loop

application/live_engine.py is the orchestrator: a single async event loop that drives the tick pipeline and coordinates background workers.

Startup sequence

1. Launcher binds an adapter (DirectMT5Adapter / RemoteMT5GatewayAdapter /

paper) behind IMT5Port.

1. Pre-flight doctor gate: MT5 terminal present? config valid? platform

supported? — otherwise the engine refuses to start.

1. Migration gate: canonical DB migration engine runs (additive, checksummed).
2. Model load: Champion bundle validated by the 10-gate load gate (manifest

hash, scaler dim, schema family, width contract…).

1. Mode select: PAPER (default) / SHADOW / LIVE (interactive confirmation).
2. Web server: FastAPI Control Center + SSE + WebSocket.
3. Workers start (audit writer, research, hygiene, incidents, Telegram).

Tick pipeline (per tick)

on_tick → normalize → features (50D) → [governed 70D assembly] → inference
        → regime → policy → risk → execution dispatch → state sync

Invariants riding on this loop:

• INV-001 — zero sync DB / training / network on the tick path.
• INV-004 — OrderManager is the only dispatch authority.
• INV-011 — broker truth wins when reconciling exposure.
• Record builders for online learning route through ONE canonical builder and

refuse (None) when the feature snapshot is not VALID — never zero-fill.

Background workers (off-path)

Audit writer (queued WAL writes), research worker, training worker (asyncio.to_thread, disabled by default), hygiene worker, incident worker, Telegram notifier (outbound only).

Runtime modes

Teardown

Foreground runs stop with Ctrl+C (graceful teardown); nexus stop handles --daemon pidfiles honestly (BUG-172: dead-pid reported as such). Updates are blocked while LIVE.

Deep dives

• Execution pipeline
• Observability
• Internal: docs/architecture/order_manager_architecture.md