TIL: Auto-Reload Files in Vim When Working With AI Agents

TL;DR A 3-line vimscript snippet that polls checktime every second keeps vim buffers in sync when AI agents modify files on disk.

• I discovered a vim trick that eliminates a common annoyance when working with AI coding agents: automatic file reloading

What I Learned

• When working with AI agents on code, a familiar loop happens:

  • AI agent edits a file on disk
  • I have that same file open in vim
  • Vim detects the change and prompts:

    "File changed since last read. Reload? (Y/N)"
    

  • Then comes the back-and-forth: approve the reload, lose your cursor position, risk overwriting the agent's work, ...

• The fix is three lines of vimscript that check for file changes every second:

  function! AutoReload()
    silent! checktime
  endfunction
  
  call timer_start(1000, {-> AutoReload()}, {'repeat': -1})
  

• checktime reloads any buffers that changed on disk

• timer_start runs it every 1000ms, forever
• Prompts gone, no more manual reloads

Why It Matters

• AI agents work best when they can edit files incrementally and watch the changes land

• The real constraint isn't agent speed—it's keeping your editor in sync with what it's doing

• This small change removes a constant annoyance

The Tradeoff

• You lose vim's ability to override git operations. For instance, you can't keep a file open in vim, run git reset --hard, then write the vim buffer to restore it
• For me, the convenience outweighs this edge case

References and Further Reading

• :help checktime in vim
• :help timer_start in vim
• .vimrc documentation on GitHub