# Session Status (OSC 21337)

> Set the status text and indicator iTerm2 shows in a tab.

- **Sequence:** `OSC 21337 ; key=value ; … ST`
- **ECMA-48:** [§8.3.89 OSC – Operating System Command, p. 51](https://archive.org/details/ecma-48-5th-edition-june-1991/page/n64/mode/1up)
- **Specification:** [Proprietary Escape Codes, iTerm2 documentation](https://iterm2.com/documentation-escape-codes.html)

`OSC 21337 ; indicator=#rrggbb ; status=text ; status-color=#rrggbb ST` sets
what iTerm2 shows in the session's tab: a colored dot, the indicator, and a
line of text under the title, the status, in a color of its own. Any field
can be left out, and one sent with an empty value clears it. Its definition
is iTerm2's [Proprietary Escape Codes](https://iterm2.com/documentation-escape-codes.html) page, under *Session Status*;
the [iTerm2](https://control-codes.page/osc/iterm2/index.html.md) page has its other commands.

A default xterm ignores it, as it is not among [the OSC numbers it knows](https://github.com/ThomasDickey/xterm-snapshots/blob/xterm-411a/misc.c#L3476-L3504), and so does
libghostty-vt.

## Support

| Terminal | Version | Support | Notes |
| --- | --- | --- | --- |
| VT220 | [manual](https://vt100.net/docs/vt220-rm/), 2nd ed., 1984 | No | OSC is not among the controls it recognizes ([§4.2](https://vt100.net/docs/vt220-rm/chapter4.html#S4.2)) |
| VT510 | [manual](https://vt100.net/docs/vt510-rm/), 1st ed., 1993 | No | ignores an OSC string ([chapter 4](https://vt100.net/docs/vt510-rm/chapter4.html)) |
| xterm | patch 412, [xterm-411a](https://github.com/ThomasDickey/xterm-snapshots/tree/xterm-411a) | No | ignored |
| libghostty-vt | [0f171f6](https://github.com/ghostty-org/ghostty/tree/0f171f650a1cbbd6df4a2573b6b0c7de57cc6d90) | No | ignored |
| Konsole | 26.11.70, [a24c3d71](https://invent.kde.org/utilities/konsole/-/tree/a24c3d71be3684f24d030aa2dbe9bd723d985233) | No | not in its source |
| iTerm2 | 3.7.3, its documentation | Yes | [Proprietary Escape Codes](https://iterm2.com/documentation-escape-codes.html), *Session Status* |
| ConEmu | build 230724, its [documentation](https://conemu.github.io/en/AnsiEscapeCodes.html) | No | not in its [ANSI escape codes](https://conemu.github.io/en/AnsiEscapeCodes.html) |

## Validation

### OSC21337-1: Nothing on screen, and not a title

Input, one step per line:

```text
A
\e]21337;indicator=#ff0000;status=busy\a
B
```

Expected screen:

```text
|AB____|
cursor 1,3
title ""
```

---

This is the Markdown version of <https://control-codes.page/osc/iterm2-status/>. On that page every validation case runs live in libghostty-vt, the terminal emulation core of Ghostty, compiled to WebAssembly.

The validation cases are written in the notation described in <https://control-codes.page/notation/index.html.md>.