In #14 and 33c7c53 I've added working support for setuptools entry_points plugins. These can be installed from PyPI using pip install ....

I imagine some projects will benefit from being able to add plugins without first publishing them to PyPI. Datasette already supports loading custom templates like so:

datasette serve --template-dir=mytemplates/ mydb.db

I propose an additional option, --plugins-dir= which specifies a directory full of blah.py files which will be loaded into Datasette when the application server starts.

datasette serve --plugins-dir=myplugins/ mydb.db

This will also need to be supported by datasette publish as those Python files should be copied up as part of the deployment.