It depends on what kind of transaction support you want. If your transactions need to span rqlite API requests then no, rqlite doesn't support that (due to the stateless nature of HTTP requests). That sort of thing could be developed, but it's substantial work. I have some design ideas, it may arrive in the future.
If you need to ensure that a given API request (which can contain multiple SQL statements) is atomically processed (all SQL statements succeed or none do) that is supported however [1]. That's why I think of rqlite as closer to the kind of use cases that etcd and Consul support, rather than something like Postgres -- though some people have replaced their use of Postgres with rqlite! [2]
[1] https://rqlite.io/docs/api/api/#transactions
[2] https://www.replicated.com/blog/app-manager-with-rqlite