Hey M,
yes, but as far as I know, no one wrote one for the buildbotics-derived Onefinity Controller yet. What you need for running an ATC, is first to populate the tool table with tool data. You can do that manually with g-code but it would be wise to implement a tool setter routine first to automate this.
And of course you would still need an ATC spindle like the Jian-Ken JGL-80 or the Mechatron ATC-8022-42-HSK25 (watch unboxing and test run video), a tool magazine, and the pneumatics to run it. See all this in action here.
The Masso G3 (used in Onefinity Elite Series) has such an ATC and tool setter support already integrated.
Image: Mechatron ATC-8022-42-HSK25 (rear view)
For introducing such g-code routines, it would be nice if Onefinity’s fork of the Buildbotics CNC Controller backported macros like available on original Buildbotics.com CNC controller since version 1.0.0. That was requested for the Onefinity many times (see also here and here) as well as the ATC functionality. But Onefinity does not support manual spindles, so I doubt the help for using ATC spindles will come from the Onefinity manufacturer. It will have to be done by the user’s community.
The original Buildbotics.com CNC Controller is still under development. It evolved a bit (What’s new in Buildbotics 1.0.0, What’s new in Buildbotics 1.0.2) since Onefinity forked it for their own controller.
PS: Mike Bogart @BNB187 wrote this Bit setter macro v2.0 (updated version) that you can enter into the ‘program-start’ and the ‘tool-change’ fields of the SETTINGS page. I have not tested it. He doesn’t use the tool table but stores the tool lengths in g-code user parameters (#31–#5000). He also wrote a ‘tool-change’ routine similar to mine.