Premiere UXP + native Add Edit: supported sequence targeting and grouped Undo?

Premiere Pro
1

Environment: Premiere Pro 26.5.2 on macOS arm64, Premiere 26 C++ SDK, UXP Hybrid Plugin SDK v6.5.0.

We are investigating direct timeline silence removal from a UXP panel, preserving existing clips and linked A/V without creating subclips.

A bounded ControlSurface prototype registers ControlSurfaceCommandBase and obtains its host command ref in Update after Connect. GetCommandCount/GetCommand enumerate global / cmd.sequence.razorateditline; ExecuteCommand successfully performs one Add Edit. On a disposable duplicate, we verified on-frame video/audio ranges, retained seeded Motion/Volume/Opacity values and keyframes, paired selection, no new Project items, and single-edit Undo/Redo. This does not establish whole-plan Undo or general effects preservation.

Before expanding this into a production Apply operation, we need two supported guarantees:

  1. Target identity at dispatch: Is there a supported native API to validate the active project and sequence identity in the same main-thread task immediately before ExecuteCommand, or bind a command to a specific sequence instead of active UI context? A UXP preflight followed by asynchronous dispatch leaves a target-change race.
  2. Whole-plan Undo and failure boundary: Can a bounded set of Add Edit and remove/ripple operations be grouped into one named Undo operation? Is there a supported integration with Project.lockedAccess()/executeTransaction(), or a native equivalent with defined partial-failure behavior?

The Hybrid build guide requires host work to be scheduled asynchronously from the scripting thread onto the main queue. The ESLint reference disallows async work inside lockedAccess/executeTransaction callbacks, so awaiting a native command inside those callbacks is not a solution.

We inspected the downloaded Hybrid SDK: UxpAddonShared.h provides value/Promise/queue APIs but no Premiere target or Undo interface. Its README documents native suite access under Photoshop-specific integration; we are not assuming that applies to Premiere.

Which Premiere-specific supported interface or workflow should we use? If this combination is not supported, confirmation would help us avoid implementing an unsafe bridge. We are not using private/QE APIs or guessed numeric command IDs, and are not asking for initial Track Lock or Linked A/V getters. Full-plan Apply remains disabled pending this boundary clarification.

Thank you.