The new APS SDK 3 is the new APS SDK for APS 24.x:
https://github.com/OpenPj/alfresco-process-services-project-sdk/releases/tag/v3.0.0
Below you can find a table describing all the versions of the APS SDK with the related supported APS versions:
| APS SDK Branch | Supported APS versions | APS SDK Artifact |
|---|---|---|
| APS SDK 3.x (3.x branch) | 24.2, 24.1 | Download APS SDK v3.0.0 |
| APS SDK 2.x (2.x branch) | 2.4.3, 2.4.2, 2.4.1, 2.4.0, 2.3.9, 2.3.8, 2.3.7, 2.3.6, 2.3.5, 2.3.4, 2.3.3, 2.3.2, 2.3.1, 2.3.0, 2.2.0.1, 2.2.0, 2.1.0, 2.0.1, 2.0.0 | Download APS SDK v2.4.1 |
| APS SDK 1.x (master branch) | 1.11.5, 1.11.4.3, 1.11.4.2, 1.11.4.1, 1.11.4, 1.11.3, 1.11.2, 1.11.1.1, 1.11.1, 1.11.0, 1.10.0.1, 1.10.0, 1.9.0.5 | Download APS SDK v1.8.0 |
Feel free to contact me for any questions 
Hope this helps 
