Posting APIs: Design Principles

A unified API for all financial movements

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A single API from Vault that can act on any financial movement. These financial movements would be between a single account’s ba lances, or between two accounts in

Vault. You can also represent the movement of funds external to the Vault system using postings

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External Integrations will use the Postings API, for example, to make postings in journeys such as Card Payments and Inter Bank Transfers. Vault Services will use the

Postings API to complete on Vault postings, such as Accrual of Interest or the Accrual of typical Fees on an account. This enabl es flexible and unified management of the

financial state of accounts on Vault.

Consistency

of financial state

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Postings are immutable, meaning they cannot be edited once they have been committed to the append only postings ledger. The bene fit of this is that you know that the

postings you see in the ledger are the original, and will never be edited or removed

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Postings are the lowest level movement of funds. Postings are not Customer Facing transactions a single Customer Transaction o r Payment can be made up of many

postings.

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Balances in Vault are always computed according to the postings within the ledger, our single source of truth for movement of fu nds.

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The Postings API guarantees consistency through following the double entry book keeping model and ensures all requests follow th is principle.

The ability to model complex financial processes

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The Postings API provides a number of Posting Types, such as Authorisation and Settlements. These types of postings are used to model complex financial processes such as

Card Payments, and the types of postings allow you to record a statement of intent with your postings

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The key benefit of these Posting Types is that we are able to enforce logical financial processes such as Authorisations & subsequent settlements of funds during a typical

Card Transaction, where we mandate an authorisation must occur before a settlement.