APIs used for Integration

Use case → Reference	`command` / primary value
S2S collect / orchestration (hub) — Collect Payment API (S2S)	Entry reference for Server-to-Server collect patterns; pair with mode-specific references below
Cards — decoupled flow — Cards Decoupled Flow	Backend collect path for decoupled cards (see page for request/response and signing)
Cards — direct authorization — Cards Direct Authorization Flow	Backend collect path for direct authorization
Cards — classic integration — Classic Integration (S2S)	Legacy/classic cards S2S pattern
UPI collect (S2S) — UPI Collect (S2S)	UPI collect server-to-server
Verify a payment — Verify Payment API	`verify_payment`
Check transaction info — Check Action Status with PayU ID	`check_action_status`
Get transaction by txnid — Get Transaction Info API	`get_transaction_info`
Refund a transaction — Refund Transaction API	`cancel_refund_transaction`

Post-service (command APIs) endpoint: POST https://info.payu.in/merchant/postservice.php?form=2
Post-service hash formula: sha512(key|command|var1|SALT)
Note: S2S “collect / authorize” calls use product-specific JSON/REST (or legacy) endpoints and signing from the linked S2S guides — not the single _payment form hash row above. For decoupled flow integration steps (non-reference narrative), see Decoupled Flow Integration (Integration).

EXAMPLE QUESTIONS