Apple has released the second beta of macOS Catalina 10.15.1 to the developers

Overview

The macOS 10.15.1 SDK provides support for developing apps for Macs running macOS Catalina 10.15.1. The SDK comes bundled with Xcode 11.2 available from Beta Software Downloads. For information on the compatibility requirements for Xcode 11.2, see Xcode 11.2 Beta 2 Release Notes.
Apple Pay

Known Issues

Safari might stop responding when attempting to use Apple Pay on the Web. You can work around this by installing Safari Technology Preview. (56261377)

eGPU

New Features

Support has been added for the AMD Navi RDNA architecture. For more information see Use an external graphics processor with your Mac.

Photos

New Features

You can now filter by Favorites, Edited, Photos, Videos or Keywords in the new All Photos view. (45589765)

You can now choose View > Metadata > Titles to enable titles and filenames in the new All Photos view. (48363059)

  macOS Catalina 10.15.1 Beta 2 released