Runtime State (Developer Guide)

What It Does

The state layer persists live order and position state for crash recovery.

Why It Exists

Without persisted state, restarts can double-apply fills or lose order ownership.

Config Dependencies

• config/state.yaml

With Backtrader

The Broker loads state automatically on start and persists snapshots.

Without Backtrader

You can use SQLiteStateStore directly for custom recovery workflows.

Limitations

• Schema mismatches require a reset.
• State is scoped by account_id and strategy_id.

Scenario Example

Scenario: You deploy a new version with schema changes. - Stop all processes. - Back up and delete the state DB. - Restart so the broker rebuilds state.