nodecode-rex

Rex: panes for long commands, read back, and this session's window named and marked. A Nodecode rewrite of kshitijk4poor/hermes-rex-plugin by kshitijk4poor.

Rex is a terminal multiplexer with a rex CLI. Run Nodecode inside one of its panes and the shell's REX_SESSION and REX_BLOCK are there, so a session knows which pane it lives in — and the model can put a dev server, a watcher or a long build in a pane beside it instead of hiding it in the background, read what it printed, and name its window after the task, with one glyph for what it is doing.

Get it

Tell the agent "add the rex cell", or run nodecode add nc://rex.

Set it up

The cell drives the rex CLI, so Rex has to be installed (it is found on PATH; a cell that cannot find it refuses to start and says so). If it lives somewhere else, give its path in the cell's binary setting (/settings).

Nothing else is needed inside a Rex pane: session and block default to REX_SESSION and REX_BLOCK. Started from somewhere else — a serve, a desktop launcher — name them:

"rex": {
  "binary": "rex",
  "session": "s-1a2b3c",   // empty reads REX_SESSION
  "block": "b-4d5e6f",     // empty reads REX_BLOCK
  "split": "below",        // where a new pane goes: below or right
  "label_words": 4,
  "timeout_seconds": 3
}

Use it

Tool	What it does
`rex_run`	Run a command in a new pane beside this one: `command`, a `label`, `split` (below or right), `keep_open`. It never takes focus, and the answer names the new pane.
`rex_capture`	The newest `lines` of a pane's output — this session's own, or one `pane` id from `rex_panes`.
`rex_panes`	Rex's sessions, and this session's windows and panes, with its own window and pane marked.
`rex_label`	Name this session's window in two to four lowercase words, and set one status mark: `busy` ●, `waiting` ?, `done` ✓, `stopped` ■, `failed` ✗, or `clear`.

The same four from the shell:

/rex                                  # where this shell is, and a panel of rows
/rex run npm run dev                  # a pane for it, beside this session
/rex capture 40                       # the newest 40 lines of this pane
/rex panes                            # sessions, windows, panes
/rex mark done                        # ✓ on this window's label
/rex rename fix-login                 # and a bare word renames, as /title does

And through eval, where an ordinary command can call it:

(rex:run "npm run dev" :label "dev-server")
(rex:capture :lines 40)
(rex:panes)
(rex:label "fix-login" :mark "done")

Every refusal is ERROR: REX-ERROR with the reason: no Rex pane (and which variable to set), a rex call that failed (with what rex said), a command or a label with no word in it.

How it is put together

The CLI is one seam, nodecode-rex::*run*, which every verb goes through: rex --autostart=false …, the session and pane passed in its environment, a timeout_seconds deadline with the process killed past it. The status glyph is a prefix on the window label read back from rex window inspect each time, so a rename by the operator or the model keeps the rest of the label; only the glyph is the cell's.

Run .github/test-cell.sh tools/nodecode-rex from the cells repository.