The Automatic Reserve mechanism can be used to handle overdraft protection, pay advancement, and many other uses. The /reserve endpoint is used to configure how the Reserve is used and how it relates to other accounts.
The Reserve features require that a special Reserve Account be created by Treasury Prime staff. In addition, the accounts holding the reserve and the target account must both be ledger accounts, not on-core accounts.
Once the Reserve Account has been created, the transaction history for that account will contain all the reserve activity.
Reserve Flow of Funds
The reserve limit for a target account can be set (see below), and then any transaction that would cause the account to go negative will have funds pulled from the Reserve Account to cover that transaction. In the case where the limit is exceeded or the Reserve Account can not cover the transaction, no funds are moved.
To reset the amount overdrawn on the target account, the amount field is reset to zero. There is no automatic mechanism to add funds to the Reserve Account and there is no automatic mechanism to remove funds from the target account. It is the responsibility of the developer to reconcile the funds using ACH, Book Transfers, or some other protocol.