OSC 52 — Clipboard set / query (base64)

OSC 52 ; Pc ; Pd ST manipulates the system clipboard. Pc selects which clipboard ('c' = CLIPBOARD, 'p' = PRIMARY, etc.); Pd is the base64-encoded data to set, or '?' to query (the terminal replies with the clipboard contents, base64-encoded). Lets a program running anywhere — including over ssh — copy to the local clipboard.

aka: clipboard · set clipboard · query clipboard · OSC 52 · ESC ] 52 · copy over ssh

parameters / subcommands

id	name	bytes (ST)	meaning
set	Set clipboard	\x1b]52;c;aGVsbG8=\x1b\	OSC 52 ; Pc ; <base64> ST sets clipboard Pc to the base64-decoded bytes. Pc: 'c' = CLIPBOARD, 'p' = PRIMARY, 'q' = secondary, 's' = select, '0'-'7' = cut-buffers; empty Pc defaults to CLIPBOARD+PRIMARY. The data field is standard base64 of the raw clipboard bytes.
query	Query clipboard	\x1b]52;c;?\x1b\	OSC 52 ; Pc ; ? ST asks the terminal to report the current contents of clipboard Pc. The terminal replies with OSC 52 ; Pc ; <base64> ST containing the base64-encoded clipboard data (if querying is enabled).

gotchas

Pd is BASE64, not raw text: you must base64-encode the bytes you want on the clipboard. A bare '?' in the data field means query, not literal data.
SECURITY: clipboard WRITE lets remote programs (e.g. over ssh) silently change your local clipboard; clipboard READ (the '?' query) lets a remote program EXFILTRATE your clipboard. xterm disables both by default (the 'allowWindowOps' / clipboard resources); many terminals disable read in particular and cap the payload size.
Some terminals impose a maximum payload length (xterm has a limit; tmux historically capped OSC 52 around 74 KB / 100 KB depending on version) — large copies may be silently truncated.
Through tmux/screen the sequence must be passed through (tmux 'set-clipboard on' and DCS pass-through); otherwise the multiplexer swallows it.
Base64 with or without trailing '=' padding: emit standard padded base64; some terminals are lenient, others strict.
There is no standard clipboard-MIME negotiation; you set/get raw bytes only.

provenance

source: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
version: xterm ctlseqs, patch #410, 2026/04/19
retrieved: 2026-05-29 · updated: 2026-05-29T00:00:00Z

per-fact attribution:

#summary — https://invisible-island.net/xterm/ctlseqs/ctlseqs.html xterm ctlseqs: Ps = 5 2 -> Manipulate Selection Data. Pc is the clipboard(s) (c/p/q/s/0-7); Pd is base64 data, '?' to report. Default Pc selects CLIPBOARD and PRIMARY.

agent: curl -H 'accept: application/json' wire.phall.io/terminal-osc/52 or /terminal-osc/52.json

OSC 52 — Clipboard set / query (base64)

frame

parameters / subcommands

gotchas

provenance

see also