Windows: Exec tool returns empty output unless pty: true

Symptoms

• On Windows (10/11), exec tool calls with pty: false (or omitted) return empty output.
• Even commands that should have side effects appear to do nothing:
  • echo test > file.txt does not create file.txt
  • Write-Output test prints nothing
• The same commands work when pty: true.

Cause

This has affected the Windows non-PTY execution path in some OpenClaw versions or sessions. Using pty: true routes execution through a different code path that can restore output while you confirm whether your installed version still has the issue.

Fix

1) Force PTY for affected exec calls on Windows

When the non-PTY path is returning empty output, include pty: true:

{ "command": "echo test", "pty": true }

2) If you need clean output, round-trip through a temp file

PTY mode can include ANSI escape sequences in the returned output. A simple workaround is to redirect output to a temp file and then read it back:

powershell -NoProfile -Command "echo test | Out-File -FilePath $env:TEMP\\exec.out -Encoding utf8; Get-Content $env:TEMP\\exec.out"

Verify

Run an exec call with pty: true:

echo test

You should see test in the tool output. If you use redirection, confirm the file actually exists and has content.

Related

• Enable Tools and Plugins (Advanced)
• OpenClaw on Native Windows: PATH, Scheduled Tasks, Node Host, and the Real Failure Modes
• OpenClaw Not Using Tools After the Update? Fix the ‘Only Chats, Doesn’t Act’ Problem
• OpenClaw docs: Exec tool
• GitHub: #19107, #20084