uloop-launch

uloop launch

Launch Unity Editor with the correct version for a project.

uloop launch is not fire-and-forget. When Unity needs to start or restart, the command waits until Unity is actually ready for CLI operations before it exits.

Usage

uloop launch [project-path] [options]

Parameters

Parameter	Type	Description
project-path	string	Optional. Use only when the target Unity project is not in the current directory.
-r, --restart	flag	Kill running Unity and restart
-q, --quit	flag	Kill an existing Unity process for the project without launching
--editor-version <version>	string	Use this Unity Editor version instead of ProjectVersion.txt
-p, --platform <P>	string	Build target (e.g., StandaloneOSX, Android, iOS)
--max-depth <N>	number	Search depth when project-path is omitted (default: 3, -1 for unlimited)

Output

May print status/progress lines before the final JSON payload, such as project path, detected Unity version, or readiness wait messages.

The final JSON payload includes:

• Success: whether the command completed
• Ready: whether Unity CLI Loop is ready for commands
• ServerReady: whether the Unity CLI Loop server accepted requests
• ProjectIpcReady: whether the project IPC path accepted tool requests
• AlreadyRunning: whether an existing Unity process was reused
• Launched: whether this command launched a Unity process
• Restarted: whether this command stopped an existing process and launched a new one
• Quit: whether this command stopped Unity without launching a new process
• PreviousProcessId: process ID stopped by restart or quit, when available
• CurrentProcessId: current Unity process ID, when available
• ProjectRoot: resolved project root
• Message: readiness summary

When not to use

A single failed, cancelled, or busy command (e.g. right after a domain reload) is not a reason to launch — retry the command instead. Running launch while the Editor is up brings the Unity window to the foreground, which disrupts the user. Reach for launch only when Unity is not running, or still does not respond after retries.

Notes

• If Unity is already running, focuses the existing window and verifies tool readiness
• If process scan is blocked (e.g. sandboxed ps), plain launch falls back to IPC probing; --restart and --quit still fail because they need the process id
• New Unity processes ignore project compiler errors during Editor startup by default when run by dispatcher 3.0.1-beta.8 or newer; run uloop update first if an older dispatcher is installed
• --editor-version only affects new Unity processes; use it with --restart to replace an already-running Editor
• The command waits until Unity finishes startup and the CLI can connect before returning