Logging and diagnostics

LocalMind writes one log file, app.log, with events from both the interface (React) and the background service (Rust). Help, then Report a Problem shows exactly what a diagnostics file would contain, lets the user save or copy it, and opens the log folder. Nothing is ever sent anywhere. The user attaches the file themselves. For the user-facing steps, see Troubleshooting.

Where it is

The log directory comes from Tauri's app_log_dir(). On Windows that is %LOCALAPPDATA%\com.zelucode.localmind\logs. One line per event:

2026-10-07T09:30:00Z WARN  [feed] message

Frontend lines have a ui: source, for example [ui:window].

What is logged

• Backend (src-tauri/src/applog.rs): startup (version and OS), key-check outcomes (provider and result only, never the key), feed downloads and failures, Advisor failures, credential-store failures, port-probe input errors and Rust panics.
• Frontend (src/lib/errorLog.ts): everything sent through logInfo, logWarn and logError (render crashes from the error boundary, dropped themes, failed feed updates, a failed diagnostics save), plus window errors and unhandled promise rejections, which main.tsx installs handlers for. In a plain browser the same calls write only to the console.
• Frontend events reach Rust through the log_event command, so both sides share one file and one format.

Keeping secrets out

• Every line passes redact() before it is written. Words after Bearer, key=, token=, x-api-key: and enc:v1: are blanked, as are words with a known key prefix (sk-, gsk_, AIza, ghp_, hf_ and others) and any word of 24 or more characters that mixes letters and digits. The diagnostics text is scrubbed again when it is built.
• Callers also avoid passing secrets in the first place. Add logInfo calls where a failure would otherwise be silent, never where a value could be a secret.
• The diagnostics file holds the app version, the OS and the last 400 log lines. It contains no file paths, keys, tools, bookmarks or settings.

Bounds

• Size. app.log rotates to app.log.1 at 5 MB, and the five newest old files are kept (app.log.1 to app.log.5, about 30 MB at most). A message is cut at 2,000 characters and flattened to one line.
• Noise. The frontend drops a repeat of an identical message within 5 seconds and forwards at most 300 events per session, so an error loop cannot fill the log.
• Failure. A failed log write is ignored. Logging must never break the app.

Commands

log_event(level, source, message), log_info() (the log folder and file path), preview_diagnostics() (the text) and save_diagnostics(), which writes localmind-diagnostics-YYYYMMDD-HHMMSS.txt to Downloads (or to the log folder when there is no Downloads folder) and returns the path. The frontend wrappers are in src/lib/backend.ts. Showing a file in the file manager uses revealInFolder in src/lib/tauri.ts, which the opener plugin permits.

Tests

• Rust (applog::tests): UTC formatting including a leap day, the one-line format, length and source cleaning, redaction of keys, headers and enc:v1: tokens while normal text is left alone, append and read back, rotation, diagnostics content with no keys or paths, and tagging of frontend sources.
• Frontend: errorLog.test.ts (console output, nothing forwarded in a browser, duplicates held back, the session cap, a backend failure never throws, the global handlers), ReportProblemModal.test.tsx, and the Help menu tests in Header.test.tsx and App.test.tsx.

Limits

• The diagnostics file is plain .txt, not a .zip: it holds only text, and a readable file lets the user check what they share.
• Not yet checked in a packaged window on every system: where the log folder is, that Downloads is found, and that "Show in folder" opens the file manager.