connect EU bank accounts via GoCardless Bank Account Data (formerly Nordigen)

Steps

1. Obtain a secret_id and secret_key from the GoCardless Bank Account Data dashboard and exchange them for a short-lived access token by POSTing to the /api/v2/token/new/ endpoint.
2. Create an end-user agreement by POSTing to /api/v2/agreements/enduser/ specifying the institution_id (from the institutions list endpoint), access_scope, and access_valid_for_days.
3. Build a requisition by POSTing to /api/v2/requisitions/ with the agreement id, redirect URL, and institution_id; the response contains a link — redirect the user to this URL to complete bank authentication.
4. After the user returns to your redirect URL, retrieve the requisition by GET /api/v2/requisitions/{id}/ and extract the accounts array of account IDs.
5. Fetch balances and transactions for each account via GET /api/v2/accounts/{id}/balances/ and GET /api/v2/accounts/{id}/transactions/ respectively.
6. Refresh the access token before it expires (default 24 hours) using the refresh token returned in step 1 by POSTing to /api/v2/token/refresh/.