How it works

The Issuer API lets card issuers integrate directly with OpenCard and distribute transaction data to connected Expense Management Systems (EMS). In addition to standard transaction data, OpenCard can attach enriched information — digital receipts, correct VAT, line items, environmental metrics — through partner networks. EMS users get a fuller picture of each purchase without you building that layer yourself.

This is not the digital receipts API on receipts.opencard.io. That is a separate product for receipt matching only. See Digital receipts if you need it.

End-to-end flow

API surface

All endpoints live under:

{base_url}/api/v1/issuers/{slug}/

Replace {slug} with the value OpenCard assigns your integration.

Area	Methods	Purpose
Cards	`POST` create, `PUT` update, `GET` one, `GET` list, `DELETE` close	Register, maintain, and inspect the card registry
Transaction states	`POST .../transaction_states`	Deliver transaction lifecycle events

Guides

Guide	What it covers
Onboarding	TPA handoff and when to start sending data
Authentication	OAuth client credentials and scopes
Cards	Create, update, list, and delete cards
Transaction states	Push purchases through their lifecycle
TPA delivery	How OpenCard delivers signed / terminated TPAs to you (email or API)

API reference → Issuer API

Environments

	Sandbox	Production
Base URL	`https://sandbox-api.opencard.io`	`https://api.opencard.io`
OAuth token	`POST {base_url}/oauth/token`	Same path

Contact support@opencard.io to start integration and receive sandbox credentials.

Issuer Integration

Digital receipts

API — Issuer

API — Receipts

End-to-end flow

API surface

Guides

Environments

​End-to-end flow

​API surface

​Guides

​Environments

End-to-end flow

API surface

Guides

Environments