uloop record-input
Record keyboard and mouse input during PlayMode frame-by-frame into a JSON file. Captures key presses, mouse movement, clicks, and scroll events via Input System device state diffing.
Usage
# Start recording
uloop record-input --action Start
# Start recording with key filter
uloop record-input --action Start --keys "W,A,S,D,Space"
# Stop recording and save
uloop record-input --action Stop
# Stop and save to specific path
uloop record-input --action Stop --output-path scripts/my-play.json
Parameters
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| --action | enum | Start | Start - begin recording, Stop - stop and save |
| --output-path | string | auto | Save path. Auto-generates under .uloop/outputs/InputRecordings/ |
| --keys | string | "" | Comma-separated key filter. Empty = all common game keys |
Deterministic Replay
Replay injects input frame-by-frame, so the game must also be deterministic to produce identical results. If the recording will be used for E2E tests, bug reproduction, or replay verification, read references/deterministic-replay.md before designing assertions or game logic.
Prerequisites
- Unity must be in PlayMode
- Input System package must be installed (
com.unity.inputsystem) - Use this only when the project already uses the New Input System.
Output
The CLI prints JSON with:
Success: Whether the operation succeededMessage: Status messageAction: Echoes which action was executed (StartorStop)OutputPath: Path to saved recording (nullable; populated onStoponly)TotalFrames: Number of frames recorded (nullable int; populated onStoponly)DurationSeconds: Recording duration in seconds (nullable float; populated onStoponly)
The CLI output contains only these six payload fields. Internal metadata such as Ver is removed before printing. There is no RecordingId, StartTimestamp, KeysCaptured, or per-frame data in the response — frame data lives only in the JSON file at OutputPath.