Write and debug AppleScript on your Mac
Shortbug is an AppleScript editor with a debugger. Set a breakpoint, run your script, and when it stops, see the line it is on, its variables, the call path, and a timed log of every statement it ran.
It is made for people who write AppleScript for work and used Script Debugger, which Late Night Software retired on May 31, 2025. Shortbug is a new, independent app.
Add date to proofs.scptd
Paused at line 8
Variables
- proofFolder
- alias "Studio:Proofs:"
- stamp
- "2026-11-10"
- pdfs
- 12 items
- aFile
- "cover.pdf"
- oldName
- "cover.pdf"
Call path
run, top level
Log
| Line | Result | Time |
|---|---|---|
| 2 | alias "Studio:Proofs:" | 2.4 s |
| 3 | "2026-11-10" | 9 ms |
| 5 | 12 items | 41 ms |
| 7 | "cover.pdf" | 3 ms |
What Shortbug does
Stop a script and look inside it
Needs a license after the trial
Turn on debug mode for a script, set breakpoints in the gutter, and run it. When it stops, you can see exactly where it is and what it holds.
- Set breakpoints by clicking the gutter. Turn them on and off, and they are saved with the script.
- Pause, resume, step over, step into, step out, or run to the line with the cursor.
- While paused, see the current line, the call path, the variables in the current handler and at the top level, and the last result. Variables are read-only in this version.
- Your file is never changed. Shortbug runs a separate instrumented copy, and a debug run is meant to give the same result as a normal run, only slower.
See what a script did
Needs a license after the trial
The event log lists each statement as it runs, so you can follow a long run after it finishes.
- Each entry shows the line, the result or error, and how long it took.
- Select an entry to highlight its line in the script.
- Copy entries to paste into a bug report or a note.
Find out what an app understands
Needs a license after the trial
Read the scripting dictionary of any scriptable app, scripting addition or script library, and use it while you type.
- Browse and search a dictionary, then insert a term or a whole tell block into your script.
- Completion knows the dictionary of the app in the current tell block.
Write and run scripts
Free to keep using after the trial
The editor and runner are free to keep using after the trial.
- Syntax highlighting, line numbers, auto-indent, and automatic closing of blocks.
- Completion for AppleScript terms and your own handlers, plus a list of handlers to jump between.
- Find and replace, and light and dark themes.
- Compile with the error marked on its line. Run, stop, or run a single handler, with the time each run took.
- Scripts run in a separate helper process, so a hung script cannot freeze the editor, and Stop ends it.
Errors that say what went wrong
Free to keep using after the trial
When a script fails, Shortbug shows the message, the error number, the object involved, and the line.
- Error -1743, where macOS has not given Shortbug permission to control an app, comes with the exact place in System Settings to fix it.
- Opens and saves .scpt, .scptd and .applescript files. If a compiled script is damaged, Shortbug recovers what it can as text instead of losing it.
Trial, free mode and license
Every copy starts with a 14-day trial with everything turned on. After that, Shortbug keeps working as a free editor, and a one-time purchase turns the debugging tools back on for good.
One-time purchase, no subscription. The price will be set before release.
Not released yet. There is no download or purchase link until the first version ships.
Free, after the trial
- Open, edit, compile, run and save scripts
- Syntax highlighting
- Basic completion
With a lifetime license
- Everything in free mode
- The debugger: breakpoints, stepping, variables and call path
- The event log
- The dictionary browser
- Completion that knows each app's dictionary
macOS 15 or later
A native Mac app. There is no Windows version and no iOS version.
Downloaded from this site
Shortbug is signed and notarized by Apple. It is not in the Mac App Store.
Asks to control your apps
macOS asks once for each app a script controls. Shortbug explains the prompt before it appears.
More questions about the trial, licensing or Script Debugger scripts: read the FAQ.