Description
To access all AIS API, a valid consent established between the TPP, the PSU and the ASPSP is needed with the the access token related to the given consent. The APIs accessible with this consent are listed below. All specifications of these APIs can be found on the API page of this developer portal.

Get list of accounts
GET /xs2a-service/v1/accounts
Returns all the accounts (at least payment accounts) that the ASPSP managed for the PSU.

Get details about an account
GET /xs2a-service/v1/accounts/{account-id}
Retrieve all the characteristics of a specific account Characteristics include - Balances (current, available) - Label - Account number - Type of the account.

Get account balances for an account
GET /xs2a-service/v1/accounts/{account-id}/balances
Returns the balances linked to the account specified.

Get transactions for an account
GET /xs2a-service/v1/accounts/{account-id}/transactions
Returns the transactions linked to the account specified.

Pagination mechanism:
If not all transactions can be returned in a single call, a pagination mechanism is included to manage the historical depth of transactions to return through a 'page' query parameter. Response body include navigation links for paginated account reports which allow redirection to first, next, previous or last page. By default the first page is indexed as 0. 

Calculation rule for the 4 calls per day at the initiative of the TPP
TPP can access each AIS resources at a maximum of 4 times per day. For example:

GET ../accounts -> 1st call on accounts
GET ../accounts/accountAAA/balances -> 1st call on Account AAA balances
GET ../accounts -> 2nd call on accounts
GET ../accounts/accountBBB/transactions -> 1st call on Account BBB transactions
GET ../accounts/accountAAA/balances -> 2nd call on Account AAA balances
Pagination mechanism
The counter is not incremented when calling the same endpoint with a different page number within 15 minutes. However, in case of a second call further in the day on the endpoint with the same query parameters (page excluded), the incrementation is applied. For example:

GET ../accounts/accountAAA/transactions/ ?page 0 -> 1st call
GET ../accounts/accountAAA/transactions/ ?page 1 -> 1st call
GET ../accounts/accountAAA/transactions/ ?page 0 -> 1st call
... more than 15 minutes later
GET ../accounts/accountAAA/transactions/ ?page 0 (More than 15 minutes after the last call) -> 2nd call
GET ../accounts/accountAAA/transactions/ ?page 2 (More than 15 minutes after the last call) -> 3rd call