That’s an interesting use case for Discourse! You’d want a custom plugin to add that data per post, as far as I know there’s not anything currently available with this functionality.
I think you’d want to do something similar to our automation plugin, which uses register_topic_custom_field_type, discourse/plugins/automation/plugin.rb at f8666b60b0fe0fd0414b4b786f9abc710187ce75 · discourse/discourse · GitHub