Glossary
Definitions of Core terms — ledger, holds, MCC, and more.
A short alphabetical reference for the terms you will encounter while integrating Core. Each entry is a one or two sentence plain-language definition. For the full data model behind any of these, follow the link to the corresponding concept page.
This glossary is a starting point and will grow. If a term you need is missing, please open an issue on the docs repo so we can add it.
Authorization
The real-time decision Core makes when a card is presented for payment. Core checks the cardholder's balance and the active spending controls, and either approves or declines the transaction.
Card
A virtual or physical payment card issued by Core that spends against a ledger account. See Cards.
Hold
A temporary reservation of funds on a ledger account, used to guarantee that an in-flight authorization will be settleable. Holds expire if not settled. See Ledger.
Idempotency key
A unique label your system attaches to a write request so that Core treats a retry as the same operation. See Idempotency Keys.
Ledger
Core's double-entry bookkeeping system. Every movement of money produces a balanced pair of entries (debit and credit). See Ledger.
Ledger account
A logical account inside the ledger. Each end user, sub-business, or financial bucket gets its own ledger account.
MCC (Merchant Category Code)
A four-digit code identifying the type of business behind a card transaction (groceries, fuel, travel, etc.). Used by spending controls to allow or block categories.
Payout
A movement of funds out of a ledger account to an external destination (Colombian bank account, another participant, etc.). See Payouts.
Settlement
The final state of an authorization where the held funds are actually deducted from the ledger account. Authorizations that do not settle within the hold window are reversed.
Spending control
A rule that constrains what a card can do — daily limits, category blocks, country restrictions. See Spending Controls.