Payment API
A payment API connects deposits, withdrawals and transaction status changes between a platform and selected payment services.
The integration in practice
Reliable payment flows require more than a successful request. Systems must agree on transaction identity, authorization, final status and reconciliation.
Core interface requirements
- Deposit and withdrawal requests, method selection and payment redirects.
- Signed status notifications, verification and duplicate-event protection.
- Pending, rejected, reversed and completed transaction states.
- Transaction history, reconciliation files and support traceability.
Supported methods, chargebacks, currencies and compliance obligations depend on the processor, operator and market.
How this connection takes shape
These steps describe the technical questions to resolve. The final implementation and deliverables are defined from the actual systems involved.
Define transaction ownership
Agree on where a deposit or withdrawal starts, which system approves the action and how the external payment reference maps to the internal wallet ledger.
Normalize status transitions
Treat pending, authorized, completed, declined, reversed and disputed states as distinct events where the payment method supports them.
Build a reconciliation path
Identify the report or endpoint used to compare processor settlements, wallet postings and customer-facing transaction history.
What we need to review
- Payment methods, currencies and target countries
- Existing wallet and finance or reporting services
- Processor documentation for callbacks, refunds and payouts
Acceptance cases to plan
- The same verified payment notification cannot credit the wallet twice.
- A pending withdrawal is never shown as settled before the required confirmation.
- A reversed payment remains traceable to its original transaction.
Questions to resolve before delivery
Can we add more than one payment provider?
A multi-provider design is possible when routing, statuses and settlement ownership are defined consistently.
How do you prevent duplicate deposits?
By correlating external and internal transaction identifiers and validating repeated or delayed callbacks against the transaction state.
Do you provide merchant accounts?
A payment API description does not include merchant onboarding or processing approval. Those are separate arrangements with an eligible provider.
How are payment signatures checked?
The implementation must follow the gateway protocol, including signature coverage, secret rotation and replay protection where available.