Right, but if your application is just a straight proxy that’s stripping out a bearer jwt or something to validate, you can’t control which documents are being synced. So you have to have 1) some understanding of the underlying protocol so you can parse the request and reject it based on user if that user does not have read/write access to the db, or 2) replicate your authorization code into couchdb with users and db permissions, at which point you have the same db per user issue (or lack thereof) plus you now have 2 user stores and 2 layers. Once this gets sufficient complexity and you try to architect something non trivial (eg. User a owns write access to document b but shares read only access to document b to user C) you end up praying to god you built the protocol parsing just right or you might accidentally let users arbitrarily write to each other’s documents.

I acknowledge that this is the same issue in a traditional dbms, but it doesn’t try to handwave away this complexity from you. It doesn’t show examples on their site about how easy replication is to set up only to be betrayed later After you’ve already integrated and marveled at the couchdb sync performance when you can’t build real permissions and would’ve been better off using Postgres and getting a bigger community and ACID/CP. and let’s be honest, almost every app is gonna need a rdbms at least for transactional data anyway (we know you’re not storing stripe billing records in your couchdb) so then the question becomes, is the sync protocol even good enough anymore to warrant using couchdb?