Hostra for payment service providers
A PSP's hardest problem is not accepting a payment — it is knowing, at any moment and for any merchant, exactly what was captured, what was settled, what is still in flight and what the provider actually did. Hostra provides the settlement engine, ledger and operational surface behind that answer.
Processing and settlement
- Every movement is a durable settlement intent written before the provider call, so an outage never leaves an undocumented action.
- Exactly-once execution through exclusive leases, fencing tokens and terminal compare-and-set commit.
- Saga orchestration with compensation for multi-leg transactions, including reversal as an explicit operation.
- Multi-rail execution: card charge, card push over Visa Direct OCT, and on-chain stablecoin disbursement.
Merchant scoping
Machine-to-machine API keys are merchant-scoped and carry RBAC scopes such as settlements:read, settlements:write, settlements:reverse and audit:read. A key issued for one merchant cannot read another merchant's settlements, and a read-only integration cannot mutate state. Settlement listings can be filtered by status — pending, in_flight, retrying, succeeded, failed, reversed — which is what operations teams actually work from.
Reconciliation and reporting
Because balances are derived from immutable double-entry postings, a reconciliation difference always points to a specific transaction rather than to an unexplained aggregate. Each settlement carries its provider reference and, where applicable, an on-chain network reference, and receipts are available as PDF and JSON artifacts for the succeeded operations that generate them. The audit hash-chain lets you prove that the history you are reconciling against has not been altered.
Operational visibility
- Outbound webhooks signed with HMAC-SHA256, retried and dead-lettered from a transactional outbox — events are never lost and never fabricated.
- RFC 7807 problem responses so failures are classifiable in your own monitoring instead of parsed from prose.
- X-Request-ID correlation from the API edge through to the settlement record.
- An ISO 8583 / ISO 20022 protocol layer for teams already working in those message formats.
Regulatory position
Hostra is technical infrastructure. It is not itself a regulated or licensed payment service provider, it does not hold regulatory authorisation, and it does not act as your acquirer or scheme member. Licensing, merchant onboarding obligations and scheme relationships remain with the PSP.