pytermwm

A modern terminal window manager in pure Python ("tmux for 2026"): tiled, floating and docked windows, desktops, themes, a status line with a built-in prompt, and four ways to drive it: the keyboard, a CLI, an HTTP/web API with a browser UI, and an MCP server so AI agents can operate your terminal.

Runtime dependency: PyYAML only (everything else is the standard library). Python 3.9+ on Linux, macOS and Windows 10 1809+ (ConPTY; Windows Terminal recommended). See Platforms.

pip install pytermwm
pytermwm                           # attach to (or create) the default session
pytermwm --standalone              # everything in one process, no daemon
pytermwm --web 8765                # ... and serve the web UI (prints the URL with its token)
pytermwm doctor                    # check that this machine can run everything

ptw is a shorter name for the same command, and python -m pytermwm works too. Or run straight from a checkout without installing anything: pip install -r requirements.txt, then the wrapper ./ptw ... on Linux/macOS, ptw.cmd ... or python ptw.py ... on Windows.

Try it in a minute

python -m pytermwm attach                      # M-Enter new window, M-h/j/k/l move, M-Space cycle layout, M-/ help
python -m pytermwm up                          # build the workspace from .pytermwm.yaml and attach
python -m pytermwm run -- htop                 # from another shell: open a window in the running session
python -m pytermwm send -t 1 -l -e "ls -la"    # type into window 1 (-l literal text, -e presses Enter)
python -m pytermwm capture -t 1                # read what window 1 shows
python -m pytermwm ctl "layout grid"           # any WM command
python -m pytermwm web                         # print the web UI URL
python -m pytermwm mcp                         # MCP server on stdio for an agent

Screenshots

modern	nes	dos
matrix	amiga	c64
bbs	mc	hacker
light	command palette (M-p)	effect matrix behind a floating window

A recorded tour (windows, layouts, the palette, themes, an effect): docs/media/demo.cast - play it with asciinema play docs/media/demo.cast or inside pytermwm with replay docs/media/demo.cast.

Making screenshots and recordings

Every picture and recording above is generated, not hand-made: python3 scripts/make_media.py drives a headless session through scripted scenes and writes docs/media/ again (--only themes|palette|effect|cast, --out DIR). The recording runs on a virtual clock, so it is the same on a slow or a fast machine.

From a running session (keys, prompt, pytermwm ctl, HTTP or MCP) the same is one command:

screenshot                       # the whole screen as an SVG in the state directory
screenshot ~/shot.svg            # .svg picture, .ans ANSI art (cat it) or .txt plain text; -f overwrites
record-screen ~/demo.cast        # asciicast v2 of the whole screen: every window, border and the status line
record-screen-stop
record -t 2 ~/win.cast           # just one window's output (record-stop to finish)

What is in the box

Platforms

!shell rule actions quote variables for the platform's shell; on Windows characters that cmd/PowerShell treat specially are replaced by _. PYTERMWM_THREADED_IO=1 and PYTERMWM_TCP=1 switch a Linux box to the Windows I/O model, which is how the Windows code paths are tested without Windows.

Documentation

• User guide - concepts, keys, prompt, sessions, everyday recipes
• Configuration - every YAML key with examples
• Automation - rules and scripts
• Plugins - bundled plugins and how to write one
• Control API - socket ops, HTTP/SSE, MCP, security model
• Command reference and MCP tools (generated)
• Contributing - bug reports, setting up, tests, generated files, pull requests
• Project management: evaluation, implementation plan, milestones, tickets, ideas

Tests

./run_tests                  # or run_tests.cmd / python run_tests.py; no install needed (-k PATTERN, -v, -f, --list)
./run_tests --threaded-io --tcp   # the whole suite in the Windows I/O model
python scripts/smoke.py      # end-to-end check of the real CLI/daemon/HTTP/MCP (any OS)
./ptw doctor                 # environment check

On Windows run_tests runs the portable subset by default (--all for everything); a few tests need a POSIX shell. GitHub Actions (.github/workflows/ci.yml) runs Linux, macOS and Windows.

The browser test in tests/test_web_ui.py runs only when playwright and a Chromium are installed (set PTW_CHROMIUM to the binary); it is skipped otherwise.

Releasing

1. Set __version__ in pytermwm/__init__.py, move the Unreleased entries in CHANGELOG.md under a ## [X.Y.Z] - date heading, and merge that to main.
2. Push the tag: git tag -a vX.Y.Z -m "pytermwm X.Y.Z" && git push origin vX.Y.Z. .github/workflows/release.yml checks the tag against the code and the changelog, builds the sdist and wheel, uploads them to PyPI with Trusted Publishing, then creates the GitHub release (the changelog section as its notes, marked "Latest") and announces it in Discussions → Announcements. Publishing a release in the GitHub web UI creates the tag and does the same.

One-time setup on pypi.org: Account → Publishing → add a (pending) publisher for owner pez2001, repository pytermwm, workflow release.yml, environment pypi. To try a build locally: pip install build twine, python -m build, twine check dist/*.

Security notes

The web server binds to 127.0.0.1 and requires a random token (Bearer header, or ?token= once which becomes an HttpOnly SameSite=Strict cookie). Host and Origin are checked, so DNS-rebinding and cross-site requests are refused. eval and the python console are off unless allow_eval: true. Rule variables are shell-quoted. Read docs/api.md before binding to another interface.