GoCardless

At a glance

Availability: Experimental (how to enable).
Auth: API key.
Connection: The key from GOCARDLESS_ACCESS_TOKEN is sent as the Bearer prefixed Authorization header.
Docs: https://developer.gocardless.com/api-reference/

Set these per environment. See Connect an integration.

Variable	Required	Description
`GOCARDLESS_ACCESS_TOKEN`	Yes	GoCardless API access token created in the dashboard under Developers. Use a sandbox token (from manage-sandbox.gocardless.com) for testing or a live token for production. Docs.

Create a sandbox account for testing: Sign up for a free GoCardless sandbox at https://manage-sandbox.gocardless.com/signup. The sandbox lets you create test customers, mandates, and payments without moving real money. Sandbox API requests go to https://api-sandbox.gocardless.com instead of https://api.gocardless.com.
Create an access token: In the dashboard (https://manage.gocardless.com for live, https://manage-sandbox.gocardless.com for sandbox), go to Developers, then Create and choose Access token. Give it read-write access if you want to create payments.
Store the token: Add GOCARDLESS_ACCESS_TOKEN=<your token> to your .env file. The token is sent as a Bearer token in the Authorization header.
Verify access: Run the List Customers tool. Every request also sends the GoCardless-Version header (2015-07-06 by default), which the API requires.

Tools call the live API at https://api.gocardless.com; for sandbox testing, point requests at https://api-sandbox.gocardless.com with a sandbox token
Amounts are integers in the smallest currency unit (pence/cents), and payments can only be created against mandates in an active or pending state
Every API request must include the GoCardless-Version header; each tool sends 2015-07-06 by default

Tool	Access	Description
List Customers	Read	List GoCardless customers to find customer IDs and contact details
List Payments	Read	List GoCardless payments with optional status, customer, or mandate filtering
Get Payment	Read	Get a single GoCardless payment by ID to check its status, amount, and linked mandate
List Mandates	Read	List Direct Debit mandates to find an active mandate before collecting a payment
Create Payment	Write	Collect a one-off payment against an existing active Direct Debit mandate
Create Subscription	Write	Set up a recurring payment collection against an existing active Direct Debit mandate
Retry Payment	Write	Retry a failed payment if its mandate is still active; a payment can be retried at most three times
List Events	Read	List GoCardless events (status changes such as payment failures, chargebacks, and mandate cancellations) for monitoring and audit workflows

List my most recent GoCardless payments and summarize their statuses, flagging any failed or charged-back payments.
List my GoCardless mandates and report which are active versus cancelled, failed, or expired.
Find the active GoCardless mandate for a customer I specify and collect a payment of the amount I provide.