Runtime Tools

Runtime tools operate inside the attached Unreal Editor process. Prefer semantic LOOMLE tools first; use runtime tools for execution, job management, profiling, and PIE play-session control.

Tool Summary

Tool	Purpose
execute	Run Unreal-side Python.
jobs	Inspect long-running job state, results, and logs.
profiling	Read official Unreal profiling data families and captures.
play	Inspect and control PIE sessions.

execute

Runs Python inside the Unreal Editor process.

Parameters

Field	Required	Notes
language	yes	Currently python.
mode	yes	exec for statements, eval for expressions.
code	yes	Python code.
execution.mode	no	sync or job.
execution.idempotencyKey	no	Deduplicate or identify a long-running request.
execution.label	no	Human-readable job label.
execution.waitMs	no	Initial wait time for job execution.

Boundary

Use public semantic tools when available. Use execute for one-off editor operations, investigation, or gaps that do not yet have a dedicated tool.

In exec mode, Loomle preflights common asset-load helper calls for package paths that start with / and contain //. Those paths can hit a UE fatal package-name assertion, so Loomle raises LOOMLE_INVALID_PACKAGE_PATH before calling unreal.load_asset or unreal.EditorAssetLibrary.load_asset when the Python APIs can be wrapped.

jobs

Inspects long-running job state, results, and logs.

Parameters

Field	Required	Notes
jobId	no	Specific job id.
tool	no	Filter by source tool.
status	no	Filter by job status.
limit	no	Limit number of returned jobs.

profiling

Bridges Unreal profiling data families such as stat groups, ticks, memory reports, and capture workflows.

Parameters

Field	Required	Notes
action	no	Profiling action to perform.
world	no	Target world.
target	no	Session participant target.
target.sessionId	no	Play/session id.
target.participant	no	Participant id.
target.role	no	server, client, editor, or standalone.
target.index	no	Participant index.
group	no	Profiling group.
capturePath	no	Capture output path.

play

Inspects and controls Unreal PIE sessions.

Parameters

Field	Required	Notes
action	yes	status, start, stop, or wait.
backend	no	Currently pie.
sessionId	no	Target play session.
map	no	Map to play.
ifActive	no	error or returnStatus.
timeoutMs	no	Wait timeout.
participant	no	Participant id.
role	no	server, client, editor, or standalone.
count	no	Participant count.
layout	no	Window layout: preset, originX, originY, width, height, gap.
strict.window	no	Require window checks.
until	no	Wait condition for session and participants.
topology	no	Server/client topology for PIE launch.

Recommended Use

Call play with action: status before starting or stopping sessions. Use action: wait when a workflow depends on PIE reaching a stable state.