nats-dart VS nats-account-server

NATS has it's own custom text based protocol, and the client ecosystem is not as mature as others', like MQTT. In fact, I developed the NATS Dart client initially to be used from Flutter apps, but now can be used on Dart servers as well. Ivan from NATS is currently working on native MQTT v3.5 support (releasing sometime soon) and v5 support landing in Q1 2021 (Source: NATS Roadmap). I see here that they're building the Go implementation from scratch, which is interesting. They also seem to be converting every MQTT topic to a NATS topic for backward compatibility (obviously, duh) - I'm not sure if this brings any challenges down the line.

NATS (at least until recently) had a very rigid authentication mechanism (just tokens and basic auth) directly configured on the server. This would be okay for hobbyists, but pales in comparison with the likes of Kafka which support LDAP atop a myriad of IDPs. NATS right now supports a form of JWT using external account providers, but this provider server should also be according to a custom spec - general purpose OAuth servers cannot be used.