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Copy to clipboard support

WebSSH1 supports2 OSC52 terminal escape sequence that allows copying text to the clipboard from within the terminal. It is supported by many other3 terminal emulators, including xterm, gnome-terminal, and iTerm2.

How to copy output to the clipboard?

It's simple as :

  • cat filename.txt | wshcopy
  • echo "WebSSH is awesome!" | wshcopy

wshcopy will handle the output and send it to WebSSH by using "invisible" terminal chars.

Clipboard Access Strategy

Since WebSSH 33.34, a remote write to the clipboard is accepted by default and signalled by a short "Clipboard updated" notice on the connection item of the terminal state bar. Nothing interrupts you, like in kitty, Alacritty, WezTerm or Ghostty.

If you prefer to approve every write, or to refuse them all, change Settings > Advanced Settings > Security > Clipboard Access Strategy to Ask (an alert for every sequence, the behaviour of versions before 33.3) or Deny. Reading the clipboard from the remote side (? query) is not supported.

How to install wshcopy

pip3 install webssh-sh

How to use with tmux >= 3.3

  • set -g allow-passthrough on THEN echo "WebSSH is awesome!" | wshcopy -t tmux
  • OR
  • set -g set-clipboard on THEN echo "WebSSH is awesome!" | wshcopy -t default

Since WebSSH 33.3, set -g set-clipboard on alone is enough for tmux's own copies (copy mode, mouse selection, tmux capture-pane -pS - | tmux load-buffer -w -) to reach the device clipboard: earlier versions ignored the empty selector tmux uses.

I would like to improve wshcopy 😛

Repository is here : webssh-sh

Documentation about OSC52 Terminal Escape Sequence

OSC 52 Sequence

The sequence consists of the following: OSC 52 ; Pc ; Pd BEL

  • Pc is the clipboard choice:
Choice Description Supported by WebSSH
c clipboard ✅
(empty) the selector tmux sends for its own buffers (set-clipboard, set-buffer -w, load-buffer -w) ✅ since 33.3
p primary ❌
q secondary ❌
s select ❌
0-7 cut-buffers ❌
  • Pd is the data to copy to the clipboard. This string should be encoded in base64 RFC-4648.
  • If Pd is "?", the terminal replies to the host with the current contents of the clipboard.
  • If Pd is neither a base64 string nor "?", the terminal clears the clipboard.

  1. Since 20.5 ↩

  2. Only copy to clipboard ↩

  3. https://github.com/ojroques/vim-oscyank/blob/main/README.md ↩

  4. Before 33.3 the default strategy was Ask. ↩

Last update: November 3, 2026