Attach Hidden Data to Topics or Posts via API

Is there a way to attach (hidden) extra data to a topic or post that can be read and written via the API

We’re looking to sync information about posts to another system and want to ‘tag’ topics and posts with a unique id from the other system as they are synced

You could write a plugin that has a post custom field and adds it to the serializer.

I would think it easier to have the other system use the post id or url.


Thanks Jay, I’m looking into the plugin approach