Clipboard

Status: xterm.

OSC 52 lets an application write to, and in principle read from, the system clipboard or selection through the PTY. It is the only clipboard mechanism that works over SSH without a forwarded display, which makes it both widely used and widely restricted.

Window Ops: xterm gates OSC 52 reads with GetSelection and writes (including clears) with SetSelection. Both are denied by default. See the Window Ops policy for the permission rules.

Syntax

OSC 52 ; Pc ; Pd ST

Pc names one or more targets; Pd is base64-encoded data, or ? to query.

Pc	Target
c	Clipboard
p	Primary selection (X11, Wayland)
q	Secondary selection
s	Select (xterm's configurable selection, usually primary)
0–7	Cut buffers 0–7 (X11 only)

Several letters may be combined: cp writes both clipboard and primary. An empty Pc means s0 in xterm. Non-X11 emulators treat everything except c (and often p) as the clipboard.

printf '\033]52;c;%s\033\\' "$(printf 'hello' | base64)"

An empty Pd clears the selection. Invalid base64 is ignored.

Behavior

Writes

The write is applied by the emulator, not the application, so it works through SSH and inside containers as long as every hop forwards the OSC. Payload limits differ: xterm truncates at its OSC buffer, tmux at 100 KiB unless raised, kitty and foot accept several megabytes. Emulators that reject an oversized write generally do so silently.

Reads

OSC 52 ; c ; ? ST asks the emulator to reply with OSC 52 ; c ; base64 ST. The reply arrives as input, so any program that can write to the terminal can read the user's clipboard, including passwords in a password manager's clipboard. Most emulators therefore refuse reads by default, and many refuse them without any configuration to enable them.

Applications should treat a read as best-effort with a timeout, and should never depend on it for correctness.

Multiplexers

tmux intercepts OSC 52 and, with set-clipboard on, both updates its own paste buffer and forwards the write to the outer terminal using the Ms terminfo capability. With set-clipboard external it forwards only; with off it drops the sequence. A read query is answered by tmux from its own buffer only when set-clipboard on. screen does not implement OSC 52; use DCS passthrough.

Probe

tools/sendosc copy 'TDN clipboard probe'
printf '\033]52;c;%s\033\\' "$(printf 'TDN clipboard probe' | base64)"
printf '\033]52;c;?\033\\'        # read; expect a reply, a prompt, or silence

Paste into another application after the first command. Use tools/query to capture any reply to the third.

Sources

• XTerm Control Sequences, OSC 52
• kitty: clipboard_control
• Ghostty: clipboard-read, clipboard-write
• foot.ini(5)
• WezTerm escape sequences, OSC 52
• Windows Terminal 1.16 release notes
• iTerm2 preferences, clipboard
• @xterm/addon-clipboard
• mintty control sequences
• tmux(1), set-clipboard

Separately tracked behavior

OSC 52 multiple targets

Feature ID: osc-52-multiple-targets. Accept a list of selection letters rather than only one target.

OSC 52 default targets

Feature ID: osc-52-default-targets. Apply xterm selection defaults when the target field is empty.

OSC 52 cut-buffer targets

Feature ID: osc-52-cut-buffers. Honor the cut-buffer digits and target letters without folding them into CLIPBOARD.

OSC 52 invalid-data handling

Feature ID: osc-52-invalid-base64-clear. Match xterm selection clearing for invalid base64 rather than silently ignoring it.

OSC 52 reply target encoding

Feature ID: osc-52-reply-target. Match the requested target spelling in selection replies.

Kitty clipboard protocol

Feature ID: osc-5522-clipboard. Separate clipboard extension, outside the current dispatch queue.

Compatibility

Feature support by terminal. Imported claims have not been reverified; unknown is not unsupported.

Feature / stable ID	Alacritty	Apple Terminal	ConPTY (conhost)	Contour	DomTerm	foot	Ghostty	iTerm2	kitty	Konsole	mintty	mlterm	PuTTY	Revenant	RLogin	st	tmux	rxvt-unicode	VTE	wayst	WezTerm	Windows Terminal	xterm	xterm.js
OSC 52 write osc-52-write	SupportedImported · unverified	UnknownImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	UnknownImported · unverified	Partial	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	PartialImported · unverified
OSC 52 read osc-52-read	UnknownImported · unverified	UnknownImported · unverified	Unknown	UnknownImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	UnknownImported · unverified	SupportedImported · unverified	UnknownImported · unverified	SupportedImported · unverified	Unknown	UnknownImported · unverified	Partial	Unknown	Unknown	PartialImported · unverified	Unknown	UnknownImported · unverified	Unknown	UnknownImported · unverified	UnknownImported · unverified	SupportedImported · unverified	PartialImported · unverified
Clipboard and selection access osc-52-selection-access	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
OSC 52 multiple targets osc-52-multiple-targets	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
OSC 52 default targets osc-52-default-targets	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
OSC 52 cut-buffer targets osc-52-cut-buffers	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
OSC 52 invalid-data handling osc-52-invalid-base64-clear	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
OSC 52 reply target encoding osc-52-reply-target	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Kitty clipboard protocol osc-5522-clipboard	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown