A payment rail your engineers can actually build on.
Greencard exposes the same API our own products run on: create payments, link and verify bank accounts, subscribe to webhooks, and pull settlement data for reconciliation.
Predictable endpoints, signed events.
Payments API
Create, retrieve, cancel and refund ACH debits. Idempotency keys on every write so retries never double-charge.
Bank linking
Hosted MX flow or a token exchange for your own UI, with instant account verification and re-auth handling.
Webhooks
HMAC-signed events for authorization, settlement, return and dispute state changes, with replay from the dashboard.
Sandbox
Full-fidelity test environment with forced return codes and settlement simulation, so failure paths get tested before launch.
curl -X POST https://api.paygreencard.com/v1/payments \
-H "Authorization: Bearer $GREENCARD_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"amount": 24500,
"currency": "usd",
"merchant_id": "mch_4Kd91",
"customer": { "id": "cus_8Xz20" },
"reference": "order-10482",
"metadata": { "pos": "cova" }
}'Already integrated where you operate.
If you run Proteus420, Cova, MJ Software, Alleaves, Acadia or Biotrack, most of the integration work is already done. For e-commerce, we support Shopify, WordPress, custom checkouts, and automated retail.
Shopify & WordPress
Drop-in checkout and plugin options for the most common merchant storefronts.
Custom e-commerce
Embed the hosted checkout or build your own with tokenized bank linking and signed webhooks.
QuickBooks
Sync payments, fees, and refunds into merchant accounting automatically.
Want API access?
Book a technical call and we will walk your team through the API, the sandbox and the integration timeline.