Plugin adds specific field for setting fastly surrogate keys. If content has that keys it will be purged by every content save/edit action for every fastly service id(you can add ids on settings page).
This plugin requires Craft CMS 3.0.0-beta.23 or later.
composer require lifechurch/purge-fastly
Configure API token and Fastly services ids on plugin's settings page
You need to add that line to your entry template at the top to create relationships between keys and objects API doc
{% header "Surrogate-Key: " ~ entry.surrogateKeys %}
After entry save/edit it'll send purge request to fastly service (if surrogate keys configured for that entry)