# 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.
## 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 . 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 .