The playbook can install and configure the Appservice Double Puppet service for you. It is a homeserver appservice through which bridges (and potentially other services) can impersonate any user on the homeserver.
This is useful for performing [double-puppeting](https://docs.mau.fi/bridges/general/double-puppeting.html) via the appservice method. The service is an implementation of this approach.
Previously, bridges supported performing double-puppeting with the help of the [Shared Secret Auth password provider module](./configuring-playbook-shared-secret-auth.md), but this old and hacky solution has been superseded by this Appservice Double Puppet method.
There are some additional things you may wish to configure about the service.
Take a look at:
-`roles/custom/matrix-appservice-double-puppet/defaults/main.yml` for some variables that you can customize via your `vars.yml` file. You can override settings (even those that don't have dedicated playbook variables) using the `matrix_appservice_double_puppet_registration_configuration_extension_yaml` variable
After configuring the playbook, run it with [playbook tags](playbook-tags.md) as below:
<!-- NOTE: let this conservative command run (instead of install-all) to make it clear that failure of the command means something is clearly broken. -->
`just install-all` is useful for maintaining your setup quickly ([2x-5x faster](../CHANGELOG.md#2x-5x-performance-improvements-in-playbook-runtime) than `just setup-all`) when its components remain unchanged. If you adjust your `vars.yml` to remove other components, you'd need to run `just setup-all`, or these components will still remain installed.