1. Introduction

This page provides an overview of API performance service level requirements for each of TPPs, the API Hub, and LFIs when implementing the CBUAE Open Finance Standards.

2. Requirements

2.1 Summary of Requirements

1. The API Performance SLA as defined in the Operational Guidelines, is set at 500ms and only applies to the endpoints listed in these guidelines.

2. The value of 500ms is split 50:50 between the API Hub and a given LFI, as the SLA is shared between both.

3. Performance is measured using the Time to Last Byte (TTLB) metric. The timer starts when the request is initiated, and stops when the last byte of data is received by the client.

2.2 Detailed Notes

The sequence diagram below shows the different steps in a typical API flow, indicating which steps are in or out of scope, and where the timer for measuring performance starts and stops. Please note the following when reading this diagram:

1. The operation for a TPP to get a new Access Token, when required, is out of scope of the SLA.

2. The time taken for a User to authenticate and authorise a consent is out of scope of the SLA.

3. The time taken for each LFI to process the authentication for each user is also out of scope of the SLA. However, LFIs must adhere to the principles set out in the Standards, in particular that this processing time must be no longer than the processing time taken when a user logs into the LFI’s web and or mobile online application, as the case may be.

4. The TTLB for each API call (e.g. post /payments) should be 500ms from the time the TPP makes the call to the API Hub to the time the TPP receives the response back from the API Hub.

5. The TTLB for each API call made by the API Hub to a given LFI is 250ms.

6. The Bulk/Batch Payments operations to upload a payment file and retrieve a payment report is out-of-scope of the API performance SLA and therefore not covered in this diagram. This is due to the inherent latency of these operations, due to the size of the data transfer being undertaken.

7. Response datasets greater than 100 records will be paged. Each page is subject to the API Performance SLA.

8. All Aani SLAs that are relevant to the end-to-end flow are shown for information and do not dictate the required flow for processing an Aani Credit Transfer.

9. All Aani SLAs must be read separately to Open Finance Framework SLAs as the subsequent steps at Aani are completed asynchronously.

10. Aani SLAs are only shown in the context of a real-time credit transfer message, as defined in Section 15.2.2.1 of the Aani Rulebook.

11. The terms “Payer” and “Payee” are used in this context as they reflect the definition of the SLA definitions in the Aani Rulebook.

3. Sequence Diagram

Open

API Performance SLA Sequence Diagram