The active REAPER project’s top-level track and master effects are checked. Take effects, input effects, nested containers and other project tabs are outside this first version. The connection recognizes Artist, Pro, Access, EFX, Hybrid and UAD Real-Time editions, but recognition is not a compatibility guarantee: the host must expose uniquely named Key and Scale controls and readable labels for every key plus Major and Minor.
Find reads settings without moving any controls. Unsupported formats are skipped with an explanation. The connection uses the track and effect’s unique IDs, checks that the selection and settings are still current, verifies the musical readout after sending, and offers conditional Undo. Retune Speed, Detune and other settings are not sent.
Two Artist instances and one Real-Time X instance were tested together on three muted, media-free tracks. All 72 transfer/Undo cases passed. Only the selected instance’s Key and Scale changed; all 108 exposed values returned to baseline after each Undo. The audio device was disabled for this test: playback, recording, automation and performance under load were not tested.
Real-Time X editor limitation: opening its custom editor stalled REAPER in this test setup. Transfer and readback passed with that editor closed. Artist’s editor displayed the requested settings normally. Do not treat this as a fully validated Real-Time X recording setup. See test details.
Run the Lua action, check that Key Lab is still running, then Find again. Stop extra copies of the action or extra REAPER sessions if the app reports multiple connections. Find again after changing the active project, replacing an effect, moving it to another track, or editing its key/scale after discovery.
A plug-in format that cannot preview its parameter labels cannot use this connection. Try another installed format of the same licensed plug-in, or use Copy settings for manual entry. Do not enable a trial merely to test another edition.