Email Mangler is an aptly named apps script that creates native filters for your Gmail account.

Deploy easily with clasp

Email Mangler can be easily developed and deployed on your own Google account using clasp.

Just follow the instructions to install clasp: https://github.com/google/clasp/blob/master/README.md

Keep a private fork for your config

Email Mangler is developed and deployed locally with clasp.

Of course, it contains an empty config, so deploying it directly wouldn't be very helpful! What I actually deploy is a private fork of the public repository, containing my personal config.

Here's how I set that up:

1. Create a temporary bare clone of this repository:

   git clone --bare git@github.com:shiinee/email_mangler.git

2. Create a new private repository on github for your personal fork. Let's say it's called shiinee/private_email_mangler.

3. Do a mirror push of your bare clone to the new private repository:

   git push --mirror git@github.com:shiinee/private_email_mangler.git

4. The local clone isn't necessary anymore; you can remove it.

5. Clone your private repository:

   git clone git@github.com:shiinee/private_email_mangler.git

6. Add the original repo as a remote to pull future changes from:

   git remote add upstream git@github.com:shiinee/email_mangler.git
   git remote set-url --push upstream DISABLE
   

   Disabling push on the remote repo will help you not accidentally push to the original repo, if you're a contributor.

That's it. You can now work on your private fork, and pull new changes from the original as needed with git pull upstream master.

(based on GitHub's instructions for duplicating a repository without forking)