How settlement works

Every fill posts through a double-entry ledger. Buyer accounts are pre-funded; a bid that would overdraw returns insufficient_balance before dispatch. Seller proceeds credit the seller account at the fill price.

Settlement is idempotent on trade_id. Replaying a matching-engine event does not double-book. Each journal entry balances; a background reconciliation job re-reads the ledger and fails the process if credits and debits diverge.

Integrators see the economic result as a completed chat response (buyer) or a row on GET /v1/sellers/{id}/trades (seller). There is no separate "settle" API — matching emits the trade and the ledger consumes it.