Concepts

The entities Core exposes — ledger, cards, spending controls, payouts, and FX rates.

Core's API is built around five entities. Each one has its own data model, lifecycle, and webhooks. Understanding them in isolation is the prerequisite for combining them in a flow.

Cards

Virtual and physical cards that spend against ledger accounts.

FX rates

Reference rates and conversion mechanics for multi-currency ledgers.

Ledger

Double-entry bookkeeping for accounts, transactions, holds, and settlements.

Payouts

Money out — to internal accounts or external destinations.

Spending controls

Real-time rules that limit what a card can do.