​

Debugging

​

Inspect Logs

• VSTO Logs – %LOCALAPPDATA%\X21\Logs\X21.log. Look for Excel API warnings, HTTP listener errors, or WebView bridge issues.
• Deno Logs – %LOCALAPPDATA%\X21\X21-deno\Logs\deno-<machine>.log. Check for router errors, Claude API failures, or tool execution details.
• Publish Logs – publish\publish.log records ClickOnce packaging output.
• Use a log viewer or editor with JSON recognition—many log lines include structured JSON payloads.

​

Use Langfuse

• Filter traces by user email or workbook name.
• Inspect spans to see which tools ran, their inputs, outputs, and durations.
• Review scores and feedback to understand user sentiment around problematic interactions.

​

Enable Debug Modes

• Set DENO_ENV=development to raise the orchestrator’s log level to DEBUG.
• In the VSTO project, build in Debug configuration and launch from Visual Studio to attach a debugger.
• Toggle DENO_CONSOLE_LOGS=true to mirror logs in the console during local development.

​

WebView Diagnostics

• Press Ctrl + Shift + I inside the task pane (if developer tools are enabled) to open DevTools for network inspection and console logging.
• Inspect WebSocket frames to verify message payloads between the UI and backend.
• Confirm Supabase auth responses and storage writes using the Application panel.

​

Validate Excel API

• Hit http://localhost:<excel-api-port>/api/getMetadata with a tool like curl to ensure the API is reachable.
• Use the Execute endpoint manually by POSTing JSON (mirroring tool payloads) to isolate whether issues stem from the backend or Excel interop.

​

Reproduce with Tests

• Run deno task test to execute unit tests covering range parsing, history management, and large history generation.
• For add-in issues, create a minimal workbook that replicates the problem and attach it to your bug report.