SQLite does not have a client-server interface. That’s ok because the creator says it is supposed to be an embedded library that gives a better fopen interface. That is, you don’t need to invent file formats (think JSON, YAML, etc). SQLite is not just a database, it’s a persistence layer that happens to have SQL interface.

It places no restrictions whatsoever on the applications that uses it. That will be pointless. Fossil-SCM uses SQLite and is itself client server.