EMS API Overview - OpenCard

This API is for EMS integrators. You manage clients, legal signing, card holders, and webhooks. Transaction data arrives via webhooks, not by polling.

Base URL

Environment	URL
Production	`https://api.opencard.io/api/v1/application`
Sandbox	`https://sandbox-api.opencard.io/api/v1/application`

What’s included

Area	Endpoints
Account	Get/update your account
OAuth Clients	Create API credentials
Public Records	Company lookup before TPA
Payment Products	Catalog of cards → enable on your account
TPAs + Signatories	Legal authorization flow
Identities	List people for instant card holder onboarding
Organizations	Your end-clients
Card Holders	List (with `identity.name` / `employee_id`), onboard employees (email or `identity_id`)
Webhooks	Receive transaction events
Receipt Scanner	OCR photo receipts

What’s NOT here

/me — end-user profile API (not for EMS integration)
/transactions query — use webhooks instead
Admin endpoints (global users, logs, statistics, etc.)

Auth

POST https://api.opencard.io/oauth/token
→ Bearer token on all requests

See Authentication.

Typical flow

GET /payment-products → POST .../payment-products/{id}
POST /accounts/{id}/tpas + signatories (payment_product_id = product id)
POST /accounts/{id}/organizations
POST .../webhooks
POST .../cardholders
Receive card.transaction.* on your webhook URL

Full walkthrough → Quickstart