capture-pane
Capture content from a tmux pane with configurable lines count and optional color preservation
LABSCO SUMMARY
The build you started an hour ago gets read, not restarted.
capture-pane returns what a pane is displaying right now, which makes an already-running process — a watch, a dev server, a half-finished REPL session — something a model can inspect without owning it. The default execution mode wraps commands, and the vendor's own note marks its edge: heredocs and other multi-line constructs conflict with the wrapping, so interactive work belongs in rawMode. Kill tools reach every level, so it is worth being deliberate about which session id ends up in a prompt.
What it is
A control surface for tmux on the same machine: sessions, windows and panes are listable, readable and killable, and commands can be run inside a chosen pane with their results collected afterwards.
What you get
- The live layout — active sessions, a session found by name, the windows in a session and the panes in a window
- The contents of a pane as it stands, with the number of lines you want and colour preserved if you ask for it
- Command execution inside a specific pane, with the result fetched afterwards by command id
- A raw mode for interactive programs — REPLs and editors — alongside the default wrapped mode
- Session and window creation, and panes split horizontally or vertically at a size you choose
- Teardown at any level: kill a pane, a window or a whole session by id
Requirements
Tmux running on the same machine as the server, with the sessions you want to reach already in it. No credentials. MIT licensed.
Setup effort
One command — npx -y tmux-mcp
USE CASES
01
Checking on a build you left running
Find the session, locate the pane it is in, and read the last lines it printed. Nothing is restarted and nothing is attached to — the process carries on exactly as it was.
02
Driving a REPL or an editor from chat
Send the command into the pane and collect its result by id afterwards. Interactive programs need rawMode, because the default mode wraps commands and that wrapping conflicts with multi-line input.
03
Laying out a workspace before starting work
Create the session, add the windows the task needs, and split panes horizontally or vertically at the size you want — so the layout exists before anything is running in it.
04
Clearing out what a long session left behind
Find the session by name, then close it at whichever level makes sense — a single pane that is finished, a window, or the whole session.
13 tools
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
create-session
Create a new tmux session
create-window
Create a new window in a tmux session
execute-command
Execute a command in a tmux pane and get results. For interactive applications (REPLs, editors), use rawMode=true. IMPORTANT: When rawMode=false (default), avoid heredoc syntax (cat << EOF) and other multi-line constructs as they conflict with command wrapping. For file writing, prefer: printf 'content\n' > file, echo statements, or write to temp files instead
find-session
Find a tmux session by name
get-command-result
Get the result of an executed command
kill-pane
Kill a tmux pane by ID
kill-session
Kill a tmux session by ID
kill-window
Kill a tmux window by ID
list-panes
List panes in a tmux window
list-sessions
List all active tmux sessions
list-windows
List windows in a tmux session
split-pane
Split a tmux pane horizontally or vertically
BEFORE YOU INSTALL
What to know first
Tools you get
13 tools when we connected.
Requires
npx on PATH
CONTEXT COST
Light Standing cost
Rated by the size of the 13 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
Connect your client
Add the block to your client, or run the command directly.
Server setup
Configuration file
JSON
{
"mcpServers": {
"tmux-mcp": {
"command": "npx",
"args": [
"-y",
"tmux-mcp"
]
}
}
}npx
TERMINAL
npx -y tmux-mcp
