tmux-mcp

tmux-mcp is an MCP (Model Context Protocol) server that exposes rich, structured context from your running tmux server so agents and tools can reason about what’s happening in your terminal.

What it does

These resources are available to any MCP-aware LLM agent, enabling workflows like:

• "Show me logs from the backend pane"
• "Switch to the pane tagged db and run migrations"
• Automatically surface failing test output to the assistant when a test pane fails

Quick start

# build binary → bin/tmux-mcp
make build

# run the server (defaults are fine for local use)
./bin/tmux-mcp

The server registers its tools & resources with MCP on start-up; compatible agents will auto-discover them.

Usage examples

Capture pane output

{
  "tool": "get_pane_output",
  "args": {
    "session_name": "mysesh",
    "window_index": 0,
    "pane_id": "%5",
    "lines": 100
  }
}

Tagging sessions for the MCP

In order to tag a pane so that is it is identified by the MCP, you must add a tag to the pane using the @mcptag prefix. This can be done manually in tmux by using the following configuration:

.tmux.conf

# Prefix + T → Tag a pane with a unique identifier
bind-key T command-prompt -p "Unique tag for pane %: " "run 'tmux-mcptag.sh %1 #{pane_id}'"

# Prefix + C-T → clear @mcptag on current pane
bind-key C-T set -p -u @mcptag

tmux-mcptag.sh

#!/usr/bin/env bash

# Script to tag a tmux pane with a unique identifier
TAG="$1"
PANE_ID="$2"

# Clear tag from any pane that has the same tag
tmux list-panes -a -F "#{pane_id} #{@mcptag}" | while read id t; do
	if [ "$t" = "$TAG" ]; then
		tmux set-option -p -u -t "$id" @mcptag
	fi
done

# Set tag on current pane
tmux set-option -p -t "$PANE_ID" @mcptag "$TAG"
tmux display-message "Pane tagged as: $TAG"

Find pane by tag

{
  "tool": "find_pane_by_tag",
  "args": { "tag": "api" }
}

Development

• Go 1.22+
• Make targets: make build, make test, make tidy
• Lint: go vet ./... or golangci-lint run
• Tests use a temporary tmux server; ensure tmux is installed.

make test   # run all tests

Project layout

cmd/tmux-mcp       – main entry-point
internal/tmuxmcp   – MCP resources & tools
internal/exec      – thin wrapper around gotmux for exec tests
internal/desc      – long-form descriptions bundled with resources

Contributing

PRs & issues welcome! Open an issue to discuss larger ideas first.

License

MIT © 2025 Nick Apisani