Control UI

Contract

Field	Bound contract
Trigger	Verify or reproduce browser/Electron UI behavior.
Authority	Write only named local evidence artifacts under the working directory and discard spawned processes on exit. Rollback: delete the evidence directory and kill any spawned process.
Side effect	Runs the app or a browser locally and captures screenshots, console logs, and DOM state into one named evidence directory.
Done	Before/after UI evidence exists in the named directory and no spawned app or browser process remains.

Inputs

Required: a UI target that is a local app command, a local URL, or an Electron entry, and the behavior to verify or reproduce.

Optional: a viewport size, an authentication state file, and an evidence directory name (defaults to a timestamped folder under the working directory).

Procedure

1. Confirm that the target is a local app command, local URL, or Electron entry supplied by the human. Refuse remote URLs or targets requiring credentials the human did not provide. Done when: the target is classified as local app, local URL, or Electron entry, and any remote or credential-bearing target is refused.
2. Create or reuse the named evidence directory under the working directory. Done when: the evidence directory exists under the working directory.
3. Capture the before state: launch the app or browser, navigate to the target, and record the viewport, screenshot, console log, and relevant DOM state into the evidence directory as before.*. Done when: before.* files (viewport, screenshot, console log, DOM state) are written to the evidence directory.
4. Perform the behavior being verified (click, input, or navigation), or follow the reported reproduction steps. Record each step taken. Done when: every behavior step taken is recorded.
5. Capture the after state: record the screenshot, console log, and DOM state into the evidence directory as after.*. Done when: after.* files (screenshot, console log, DOM state) are written to the evidence directory.
6. Compare before and after evidence against the expected behavior. Record pass, fail, or mismatch with the differing evidence file names. Done when: a pass, fail, or mismatch classification is recorded citing the differing evidence file names.
7. Terminate every spawned app or browser process and confirm none remain. Done when: no spawned app or browser process remains.

Failure and recovery

• Launch failure: the app or browser did not start. Record the error, leave no process, and return blocked with the launch error.
• Behavior not reproducible: the after state matches the before state. Record both evidence sets and return the mismatch classification; do not invent a difference.
• Process leak: a spawned process remains after capture. Kill it by PID; if it cannot be killed, return blocked naming the PID.
• Partial result: if capture fails mid-run, keep the before evidence, discard incomplete after artifacts, and return blocked naming the failed capture step.
• Rollback: delete the evidence directory and kill any spawned process; the working tree returns to its prior state.

Output

A before/after evidence directory containing screenshots, console logs, and DOM state, plus a one-line classification (pass, fail, mismatch, or blocked) citing the evidence file names.