ExtendPay API — Overview¶
ExtendPay opens Billtrust-hosted checkout from your systems using your invoice and statement data. Create a session, send the buyer to the payment URL, then confirm the outcome by reading the session and/or receiving a webhook when payment completes.
Swagger documentation:
https://swagger-ui.aws-prod.billtrust.com/?urls.primaryName=BTPay%20ExtendPay%20Service%20v1
Base URL¶
https://arc-aegis.billtrust.com/btpay-extendpay
Session APIs live under /v1/tenants/{tenantId}/sessions.
ExtendPay must be enabled on your tenant before you integrate. Contact Billtrust Support or your implementation contact if it is not.
Flow¶
1. (Optional) Have an admin configure webhook URL + signing secret
2. POST /sessions → extendPaySessionId, paymentUrl, sessionExpiration
3. Open paymentUrl for the buyer
4. Buyer completes checkout
5. Confirm via GET /sessions/{id} and/or webhook (status Complete)
Sections¶
| Section | Description |
|---|---|
| Create session | Start checkout with buyer and document data |
| Get session | Read one session |
| List sessions | Page sessions for your tenant |
| Webhooks | Signed notification when a session completes |
| Errors | Error response shape and status codes |
Session status¶
| Status | Meaning |
|---|---|
Open |
Session created; checkout may still be in progress |
Failed |
Session could not be set up |
Complete |
Checkout finished; payment details are available |
Only Complete sessions send a webhook.