wutch watches for changes in the directories and runs a shell command for every change. It can also open a browser a display whatever is in the build directory, just like Live Server.

Common use case for Wutch involves writing docs with Sphinx. Wutch will watch for the changes in all *.rst files and automatically rebuild documentation. It will also open a browser window pointing to the build directory and inject every built webpage with a code that will auto-refresh that page after each rebuild.

PyPI Documentation Status



pip install wutch


Just run wutch in the directory where you want to watch for the changes. By default, wutch will:

  • Watch for every change in the current directory.

  • Ignore changes in the _build/ and build directories.

  • Run sphinx-build shell command for every change in the files.

  • Open a browser pointing to index.html in the _build directory.

  • Automatically refresh that page every time you change the files and shell command runs.

$ wutch -vvv

2021-04-10 12:33:16.367 | DEBUG    | wutch.watcher:start:25 - Starting observer thread
2021-04-10 12:33:16.368 | DEBUG    | wutch.watcher:on_any_event:58 - Processing event <FileModifiedEvent: event_type=modified, src_path='docs', is_directory=False>.
rm -rf "_build"
#@poetry run sphinx-build -M build "." "_build"
Running Sphinx v3.5.3
loading translations [en]... done
making output directory... done
building [mo]: targets for 0 po files that are out of date
building [html]: targets for 1 source files that are out of date
updating environment: [new config] 1 added, 0 changed, 0 removed
reading sources... [100%] index
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... done
writing output... [100%] index
generating indices... genindex done
writing additional pages... search done
copying static files... done
copying extra files... done
dumping search index in English (code: en)... done
dumping object inventory... done
build succeeded.

The HTML pages are in _build/html.
2021-04-10 12:33:17.627 | DEBUG    | wutch.watcher:on_any_event:71 - Shell command executed with result: None.
2021-04-10 12:33:17.627 | DEBUG    | wutch.events:report:15 - New Event.ShellCommandFinished event has been reported.
2021-04-10 12:33:17.627 | DEBUG    | wutch.watcher:start:28 - Observer thred started
2021-04-10 12:33:17.628 | DEBUG    | wutch.server:start:44 - Server thread started
2021-04-10 12:33:17.628 | DEBUG    | wutch.server:open_browser:137 - Opening browser at: http://localhost:5010/index.html

Stop wutch by pressing Ctrl+C key sequence.

^C2021-04-10 12:33:28.396 | DEBUG    | wutch.threaded:run:28 - Stopping all threads on KeyboardInterrupt
2021-04-10 12:33:28.397 | DEBUG    | wutch.watcher:stop:32 - Stopping observer thread
2021-04-10 12:33:28.560 | DEBUG    | wutch.watcher:stop:35 - Observer thread stopped
2021-04-10 12:33:28.560 | DEBUG    | wutch.server:stop:58 - Server thread stopped



-h, --help            show this help message and exit
-c COMMAND, --command COMMAND
                  Shell command executed in response to file changes. Defaults to: sphinx-build.
-C CONFIG, --config CONFIG
                  Path to the wutch config file. Defaults to: wutch.cfg.
-d [DIRS ...], --dirs [DIRS ...]
                  Directories to watch (separated by ' '). Defaults to: ['.'].
-p [PATTERNS ...], --patterns [PATTERNS ...]
                  Matches paths with these patterns (separated by ' '). Defaults to: ['*'].
-P [IGNORE_PATTERNS ...], --ignore-patterns [IGNORE_PATTERNS ...]
                  Ignores changes in files that match these patterns (separated by ' '). Defaults to: ['_build/', 'build/'].
-w WAIT, --wait WAIT  Wait N seconds after the command is finished before refreshing the web page. Defaults to: 1.
-b BUILD, --build BUILD
                  Build directory containing files to render in the browser. Defaults to: _build/html.
-I [INJECT_PATTERNS ...], --inject-patterns [INJECT_PATTERNS ...]
                  Patterns of files to inject with JS code that refreshes them on rebuild (separated by ' '). Defaults to: ['*.htm*'].
-i INDEX, --index INDEX
                  File that will be opened in the browser with the start of the watcher. Defaults to: index.html.
--host HOST           Host to bind internal HTTP server to. Defaults to: localhost.
--port PORT           TCP port to bind internal HTTP server to. Defaults to: 5010.
-B, --no-browser      Do not open browser at wutch launch. Defaults to: False.
-S, --no-server       Do not start the webserver, just launch the shell command. Defaults to: False.
-v, --verbose         Log verbosity. Has four levels: error, wargning, info, and debug. Can be stacked: -v (for warning) or -vvv (for debug).
-V, --version         Display version of the wutch.

Loading order

Wutch loads configuration settings in the following priority:

  1. Command line arguments

  2. Environment variables starting with WUTCH_

  3. Configuration file wutch.cfg

  4. Default variables

Every variable can be specified in any of the sources above, thanks to ilexconf configuration management library.

For example, dirs variable that lists directories to watch can be specified in several ways:

Command line:

wutch --dirs . ../other_dir

Environment variables starting with WUTCH_:

export WUTCH_DIRS=". ../other_dir"

Configuration file wutch.cfg:

   "dirs": [".", "../other_dir"]

Wutch’s documentation is built using wutch

Take a look at the wutch.cfg file at the root of the repository. This serves as a somewhat common configuration for Sphinx dependent documentation.

Wutch documentation is developed using wutch and this config below.

   "dirs": ["docs"],
   "patterns": ["*.rst", "*.py"],
   "ignore_patterns": ["docs/_build/"],
   "command": "make -C docs rebuild",
   "build": "docs/_build/html",
   "inject_patterns": ["*.html"],
   "index": "index.html",
   "host": "localhost",
   "port": 5010