Would it be possible to have a API for another database with its own topics, posts, search and integrate that into Discourse so I can use Discourse as a front end and that as an backend?

No. Think about import your data.

Is it possible to import 500gb+? Or is there a size limit

Integrate an existing database to Discourse

Falco (Falco) July 17, 2023, 10:21pm 5

No, there is no size limit.

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