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aqandrew · 2026-06-16T21:33:22Z

Registers an OSC 52 handler on the xterm.js terminal parser so that programs like tmux can copy text to the browser's system clipboard via escape sequences (e.g. printf "\\033]52;c;$(echo -n 'Coder is Cool' | base64)\\a").

The handler decodes the base64 payload and writes it using the existing copyToClipboard utility, which provides an HTTP fallback for insecure contexts. Clipboard read queries (?) are ignored since responding would require writing back to the PTY.

No new dependencies are needed; xterm.js 5.5.0 already exposes terminal.parser.registerOscHandler.

Closes #16577

Generated by Coder Agents on behalf of @aqandrew.

relevant context from agent chat, summarized by me

ref DEVEX-465

Installing @xterm/addon-clipboard would have been another way to implement this feature. This would follow established addon-loading patterns in WorkspaceTerminal:

coder/site/src/modules/terminal/WorkspaceTerminal.tsx

Lines 232 to 241 in 612b6d4

    
           const fitAddon = new FitAddon(); 
        
           fitAddonRef.current = fitAddon; 
        
           nextTerminal.loadAddon(fitAddon); 
        
           nextTerminal.loadAddon(new Unicode11Addon()); 
        
           nextTerminal.unicode.activeVersion = "11"; 
        
           nextTerminal.loadAddon( 
        
           	new WebLinksAddon((_, uri) => { 
        
           		handleOpenLink(uri); 
        
           	}), 
        
           );

However, registering a custom handler instead has a few advantages re: security and flexibility:

security
- ignoring OSC 52 with clipboard read queries (payload === "?") prevents processes in the workspace from reading the user's clipboard without consent
flexibility
- ignoring OSC 52 with invalid base64 -- If the addon catches an error while decoding base64, an empty string will be copied to the clipboard, i.e., the clipboard contents get cleared, which would be surprising/frustrating to users. The custom handler doesn't write anything to the clipboard in this case.
- ignoring OSC 52 with missing separator -- The addon returns true in this case (marks the OSC 52 as handled); the custom handler returns false (doesn't mark the OSC 52 as handled)

The approach/tests seem sound to me. I would just ask that someone among reviewers manually test this with tmux, since I'm not a tmux user 🙏🏽

Register an OSC 52 handler on the xterm.js parser so that programs like tmux can copy text to the browser's system clipboard via escape sequences. The handler decodes the base64 payload and writes it using the existing copyToClipboard utility, which provides an HTTP fallback for insecure contexts. Closes #16577

aqandrew

Clean, well-scoped feature. The OSC 52 parsing is correct, the UTF-8 decode path via Uint8Array.from(atob(...)) + TextDecoder handles multi-byte characters properly, and the test exercises the real xterm parser end-to-end. Good reuse of the existing copyToClipboard utility.

2 P3s and 1 nit across 3 inline comments.

Fix comment accuracy: 'let the default handler run' to 'ignore' since xterm.js has no built-in OSC 52 handler. Restore navigator.clipboard after test using save/restore pattern in a scoped describe block. Add edge-case tests for missing separator, clipboard read query, and invalid base64.

linear-code · 2026-06-25T00:48:05Z

DEVEX-465

coderagents · 2026-06-25T00:49:09Z

Documentation Check

Updates Needed

docs/user-guides/workspace-access/web-terminal.md - The "Key Features" list and "Copy/Paste Behavior" subsection should mention OSC 52 clipboard support. Programs like tmux can now copy text to the browser clipboard via escape sequences, which is a meaningful capability for terminal users. A short bullet or paragraph (e.g., "OSC 52 clipboard: Programs like tmux can copy text to your browser clipboard using the OSC 52 escape sequence. Clipboard read queries are ignored for security.") would be appropriate.

Automated review via Coder Agents

ThomasK33

I think it looks good, but I don’t have enough context or knowledge to assess the change confidently.

If you’re confident about it and just need a quick stamp of approval, let me know.

aqandrew · 2026-07-06T19:27:23Z

I wasn't 100% comfortable merging this until somebody could verify it working manually, but we're good now! 🙂 I just successfully did this with @jeremyruppel:

repro steps

in your Coder deployment, open the web terminal by navigating to the URL /:username/:workspace/terminal
make sure the tmux command is installed in your workspace
- it's included by default in the Write Coder on Coder template
create a ~/.tmux.conf configuration file if it doesn't already exist
give tmux permissions to write to the clipboard, by adding this line to ~/.tmux.conf:
```
set -g set-clipboard on
```
reload your tmux configuration (run this outside of tmux):
```
tmux source-file ~/.tmux.conf
```
launch tmux
run this command (from OSC52 Support for coder web terminals #16577) inside tmux:
```
printf "\033]52;c;$(echo -n 'Coder is Cool' | base64)\a"
```

Coder is Cool gets copied to your clipboard

github-actions Bot assigned aqandrew Jun 16, 2026

aqandrew commented Jun 17, 2026

View reviewed changes

Comment thread site/src/modules/terminal/WorkspaceTerminal.tsx

Comment thread site/src/pages/TerminalPage/TerminalPage.test.tsx Outdated

Comment thread site/src/pages/TerminalPage/TerminalPage.test.tsx Outdated

aqandrew requested review from DanielleMaywood, ThomasK33 and zenithwolf1000 June 25, 2026 00:46

aqandrew marked this pull request as ready for review June 25, 2026 00:47

ThomasK33 reviewed Jun 25, 2026

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zenithwolf1000 approved these changes Jun 25, 2026

View reviewed changes

github-actions Bot added the stale This issue is like stale bread. label Jul 3, 2026

aqandrew merged commit 95fde35 into main Jul 6, 2026
47 checks passed

aqandrew deleted the aqandrew/osc52-clipboard-support branch July 6, 2026 19:27

github-actions Bot locked and limited conversation to collaborators Jul 6, 2026

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feat(site): add OSC 52 clipboard support to web terminal - #26437

feat(site): add OSC 52 clipboard support to web terminal#26437
aqandrew merged 2 commits into
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aqandrew/osc52-clipboard-support

aqandrew commented Jun 16, 2026 •

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	const fitAddon = new FitAddon();
	fitAddonRef.current = fitAddon;
	nextTerminal.loadAddon(fitAddon);
	nextTerminal.loadAddon(new Unicode11Addon());
	nextTerminal.unicode.activeVersion = "11";
	nextTerminal.loadAddon(
	new WebLinksAddon((_, uri) => {
	handleOpenLink(uri);
	}),
	);

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aqandrew commented Jun 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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relevant context from agent chat, summarized by me

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linear-code Bot commented Jun 25, 2026

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coderagents Bot commented Jun 25, 2026

Documentation Check

Updates Needed

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aqandrew commented Jul 6, 2026

repro steps

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aqandrew commented Jun 16, 2026 •

edited

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