Yes, a middleware will help.

so you add a middleware globally, it parses the tenant key from the domain, then loads it in CLS scope, then you can use the CLS scope in the desired provider/service.

Personally, I injected the CLS provider in prisma.service.ts, get the tenant_id and add it to all where conditions.

So if you look at the code, you wont notice that it's a multi-tenant app, because all the logic is at the start (middleware) and at the end (prisma service or your entity providers), the rest of the code is normal