Core service¶

Core service is a simple transaction ledger which provides basic functions for payment processing.
The service communicates only with Public API service and 3d party connectors.
Service should be deployed in DMZ network zone and protected with encryption and Service-to-Service authentication mechanism
Money stored in cents (atomic currency unit)

Entries or ledger record¶

Ledger structure:

Operations, represents sufficient customer’s operation on the wallet.
Wallet requests (any request to the service, contains information about initial request: type, amount, currency, etc)
Entries, an atomic ledger record consists of debit and credit source, type, amount, currency, input/output balance
Entries are formed accordingly to the wallet request type an account settings (commission, operation type)
Each entry is linked to: the operation, wallet request, wallet itself

Operation 1 of type ‘charge’ is created (invoicing a client)
No entry record created
Operation 2 of type ‘pay’ is created (paying the invoice) and linked to Operation 1
Entry 1 of ‘hold’ type is created on customer’s wallet (funds moved from actual customer’s balance to the system designated for holdings wallet)
Entry 2 created with type ‘commission’ (commission amount is moved from merchant’s wallet to the system designated wallet)
Request to 3d party gateways is sent and logged
Entry 3 with type ‘pay’ (funds are moved from system hold wallet to a merchant’s wallet)
Operation status updated
Result posted back to Public API which is sending notification to the merchant

Entries could be of the following types:

Entry direction is defined by Debit (deduct funds) to Credit (fund the account) cash flow concept.

Entries are not a subject of any modifications, and meant to be persistent and immutable data.