cursor-hooks-windows

name	cursor-hooks-windows
description	Fix Cursor beforeShellExecution hooks on Windows when stdout is invalid JSON or empty. Use for hooks-allow.bat, validate-mounted-env-files.sh, 1Password plugin, or "blocked for safety" agent terminal errors on Synthex (Windows 11).

Cursor Hooks — Windows Invalid JSON Fix

Trigger phrases

• beforeShellExecution returned stdout that is not valid JSON
• preToolUse returned stdout that is not valid JSON
• pre-bash-validate.py
• hooks-allow.bat
• validate-mounted-env-files.sh
• Agent shell blocked but integrated terminal works

Root cause (Windows)

1. Cursor pipes hook input JSON on stdin to the hook process.
2. A bare echo {"permission":"allow"} in .bat does not reliably write to stdout when stdin is piped — hook log shows OUTPUT: (empty).
3. Cursor then parses garbage (exit status…) as JSON and blocks the agent command.

Iron rule: Hook must read stdin, then write only this to stdout (plus newline):

{ "permission": "allow" }

Fix pattern (use this)

Preferred: Node (allow-hook.cjs)

'use strict';
const fs = ();
 {
   (!process..) fs.(, );
}  {
  
}
process..(.({ :  }) + );
process.();