You can use Optimus from the command line tool optimus-cli. A global help is available with :

optimus-cli -h

Or specific command action help with :

optimus-cli COMMAND -h

There is also a common command argument --settings-name that is useful to define the settings files to use. It appends a Python path to the settings file. For common usage you just have to give the filename without the .py extension, otherwise you will get an error message.

Create a project

At least you will give a name for the new project. Be aware that it must a valid Python module name, so only with alphanumeric characters and _. No spaces, no dots, etc.. :

optimus-cli init my_project

It will create project directory and fill it with basic content. There is a sample project template named basic which create a basic project with everything pre-configured to quickly start with settings modules, page views, i18n enabled and assets management.

All project template includes a Makefile to ease install and usage, CherryPy is installed by default and Assets settings use rcssmin and jsmin (Pure Python asset minifiers).


Configure your settings if needed, then your Pages to build and finally launch Optimus to build them :

optimus-cli build

Managing translations

Optimus can manage your translations for the known languages of your project. This is done in the setting LANGUAGES where you define a list of locale names, each of which will have a translation catalogs after you initialize them. By default, this settings is only filled with the default locale defined in the settings LANGUAGE_CODE. This is your responsability to fill the setting LANGUAGES with valid locale names.

Assuming you want to add French translations, you will have to add this setting :

# A list of locale name for all available languages to manage with PO files

Note the first item that also adds the locale name from the default language from the setting LANGUAGE_CODE.

Then you will need to flag the strings to translate in your templates with the {% trans %} template tag from Jinja2 (see Jinja2 template documentation for more details) like this :

    <h1>{% trans %}Hello world{% endtrans %}</h1>

And finally manage your translation catalogs, see below.


On a new project you have to initialize the catalog template (the source used to create or update translation catalogs, represented by a *.POT file in your locales directory) :

optimus-cli po --init

This will extract translation strings from your templates (and other files in your sources directory if needed) and put them in catalog templates, then after translation catalogs will be created from the template for each knowed languages.

This command is safe for existing translations, if a translation catalogs allready exists, it will not be overwrited. Only non existing translation catalogs will be created.

Now open your catalog files (*.PO) edit them to fill the translations for your languages, then compile them (see Compilation).


If you do some changes on translations in your templates, like add new translation strings, modify or remove some, you have to update your catalogs to adapt to this changes :

optimus-cli po --update

This will extract again your translation strings, update the catalog template then update your translation catalogs. After that you will have to re-compile them (see Compilation).


Catalog files (*.PO) are not usable for page building, you will have to compile them first, this is done with the command line :

optimus-cli po --compile

It will compile the catalog file to *.MO files, this way Optimus can use your translations. Remember that when you do updates on catalog files you will have to re-compile them each time, this is not automatic.

Note that also when you edit your translation catalogs to change some translations, you will have to re-compile them.

Watch mode

Use the watch command action to automatically rebuild files at each change in your sources :

optimus-cli watch

This will launch a process that will watch for changes and rebuild pages if needed. For changes on templates, the watch mode will only rebuild pages that uses the changed templates. Also if it detects that the publish directory (from the setting PUBLISH_DIR) does not exists, it will automatically performs a first build.

To stop the watcher process, just use the common keyboard combo CTRL+C.

This is useful in development, but note that the watcher is limited to watch only for templates and assets changes.

Watch mode will not detect if :

  • You change some things in your Page views, your settings or your RST files;
  • You add new static files;
  • You make some changes in your translation files (*.pot and *.po);

For theses cases you will have to stop the watcher, manually rebuild with build command or Babel tool (for translations only) then relaunch the watcher.

Web server

You can launch a simple web server to publish your builded content, it’s not intended to be used in production, only for debugging your work. This command action is only available if you already have installed cherrypy, see the Install document about this.

The hostname argument is required and it should at least contain the port (like ‘80’), the default address will be “” if you don’t give it.

To launch the webserver binded on your local IP on port 8001 to publish your project from the default settings, do this :

optimus-cli runserver

Or you could bind it on localhost on port 8080 with the production settings :

optimus-cli runserver localhost:8080 --settings-name=production

The settings are used to know the publish directory to expose.

Note that the server does not build anything, it only expose the publish directory to publish the builded page and static files it contains. You should launch the Watch mode in parallel.