Is WP_Query not efficient? (I’m not a WP expert, so just curious)
This post might help speed things up
I’m leaning toward not adding an external_post_id because I feel like keeping track of the topic_id which the api returns should be the responsibility of the integrator not Discourse. In order to make looking up a topic by external_post_id efficient in Discourse we would also have to index the column in the db table and create/modify an api endpoint to allow for searching by that param.
If there is no advantage to using one or the other right now, I’m going to push you do use the topic_id in the metadata. I guess I’m having a hard time seeing the downside if you are already tracking the topic_id that you couldn’t just hit the /t/{id}.json endpoint and get the title and the posts_count?