# Release History
source: https://developer.mastercard.com/authentication-facilitator/documentation/pre-release-notes/index.md

This page contains Pre-Release Notes for the Authentication Facilitator Application Programming Interface (API), providing early warning of intended changes and additions to the APIs. Only once the API update has been released to Mastercard Test Facility (MTF) will the specification be updated in the main Mastercard Developers documentation. So the pre-release notes are the only place where coming changes are documented in advance of each MDES platform release.
Note: The Authentication Facilitator API is developed in an agile manner and is updated regularly with the MDES Platform Updates. Every effort is made to retain backwards-compatibility as changes occur. To ensure forward-compatibility, all Authentication Facilitator API client integrations must be resilient to the addition of new elements being added to requests and responses. Existing implementations should strive to keep updated to the latest API version available with each new MDES Platform Update release.

Every effort will be made to provide as much warning of change as possible, with a target of providing at least 3 months notice.

|                                                               Authentication Facilitator API Version                                                                |   Release   |    Type of Note    | Date of Upgrading |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|--------------------|-------------------|
| [March 2026 Pre-Release Notes](https://developer.mastercard.com/authentication-facilitator/documentation/pre-release-notes/march_2026_pre_release_notes/index.md)   | 2026 March  | Pre-warning Notice | 20 January 2026   |
| [August 2021 Pre-Release Notes](https://developer.mastercard.com/authentication-facilitator/documentation/pre-release-notes/august_2021_pre_release_notes/index.md) | 2021 August | Pre-warning Notice | 10 June 2021      |