logs-skill

Lens Studio Log Analysis

Log File Location

Both RecompileTypescriptTool and RunAndCollectLogsTool return a logFile path in their response. If the path is not available from a recent tool call, use ExecuteEditorCode to obtain it:

const FS = await import("LensStudio:FileSystem");
return FS.getLogFile().toString();

This returns the full path to the active log file (e.g. ~/Library/Preferences/Snap/Lens Studio Internal/logs/LensStudioLog-<timestamp>.txt). Once obtained, use your built-in Read and Grep tools to read logs directly from the filesystem.

Log Format

Each line follows this structure:

<LEVEL> <HH:MM:SS.mmm> <source_file>:<line> (<@thread>) <function>] <message>

• Levels: D=debug, I=info, W=warning, E=error, F=fatal
• Thread: Always prefixed with @. Identifies the subsystem that produced the log.
• The <function>] segment ends with a closing bracket before the message.

Example:

E 14:32:01.456 TypeScriptCompiler.cpp:285 (@Es::TypeScript) compileProject] TS2304: Cannot find name 'foo'.
I 14:32:05.789 PreviewWorker.cpp:142 (@Es::Preview::PreviewWorker) onScriptLog] Hello from script!

Log Categories by Thread

Category	Thread pattern	What it contains
TypeScript compiler	@Es::TypeScript	Compilation start, success, failure, TS errors
Preview runtime	@Es::Preview::PreviewWorker	Script print() output, runtime errors, lifecycle
Device push	@Es::ToDevice	Device deployment logs
Main / other	everything else	UI, asset management, general engine

Compilation Workflow

1. Trigger: Call RecompileTypescriptTool — it triggers recompilation and waits for success/failure.
2. On success: Tool returns { status: "succeeded", logFile: "..." }. No further action needed.
3. On failure: Tool returns { status: "failed", errors: [...], logFile: "..." }.
   • Read the errors array first — it contains the compiler error messages directly.
   • For deeper analysis (surrounding context, related warnings), use Read/Grep on the logFile path:

# Find TypeScript compiler errors (level E, TypeScript thread)
Grep the log file for: ^E .* @Es::TypeScript

# Or for specific TS error codes:
Grep the log file for: TS\d{4}:

4. Fix the errors in the source .ts files, then call RecompileTypescriptTool again.

Preview Runtime Workflow

1. Trigger: Call RunAndCollectLogsTool — it refreshes all preview panels and waits for the lens reset signal.
2. Read the response. The tool returns metadata only:
   • status: "success" | "timeout" | "no_preview"
   • logFile: Absolute path to the active log file
   • byteOffset: Byte position in the log file before the refresh was triggered
3. Wait briefly: Run sleep 0.5 to let script initialization complete (onAwake errors happen ~100ms after reset).
4. Read new log entries: Use Read or Grep on logFile starting from byteOffset to see only entries produced by the refresh:
   • Script print() output: grep '@Es::Preview::PreviewWorker.*onScriptLog\]' logFile
   • Preview runtime errors: grep '^E .* @Es::Preview::PreviewWorker' logFile
   • Use the grep patterns in the quick reference below for other categories.
5. On timeout: The reset signal wasn't received in time. Logs may still contain partial output — read from byteOffset anyway.
6. On no_preview: No preview panel is open. Ask the user to open one, or check that the project has a scene loaded.

Grep Patterns Quick Reference

Scenario	Pattern
Compilation succeeded	TypeScript compilation succeeded!
Compilation started	Starting TypeScript compilation
Compilation failed	TypeScript compilation failed!
TS compiler errors (level E)	^E .* @Es::TypeScript
Specific TS error code	TS\d{4}:
Preview reset marker	Lens has been reset
All preview runtime logs	@Es::Preview::PreviewWorker
Script print() output	@Es::Preview::PreviewWorker.*onScriptLog\]
Preview runtime errors	^E .* @Es::Preview::PreviewWorker
Device push logs	@Es::ToDevice

Efficient Log Reading Tips

• Tail the file: Use Read with a large offset (e.g. total lines - 200) to see only the most recent entries. Logs accumulate over the session; old entries are rarely relevant.
• Anchor to event markers: After triggering compilation or preview reset, grep for the marker (TypeScript compilation succeeded! or Lens has been reset) to find the exact region of interest, then read a window around that line.
• Filter by level + thread: Combine level prefix and thread to narrow results. E.g. ^E .* @Es::Preview::PreviewWorker for preview errors only.
• Multiple grep passes: First grep for the event marker to get the line number, then read lines after that marker with a category filter.