It probably could be implemented as pure plpgsql for some of its features (basic send/receive). The long-term plan is to add additional message type support (protobuf, msgpack, etc), embed a metrics exporter (prometheus?), push notifications, and. for those we want to pull in Rust modules from open source. I bet the project could be refactored to expose the parts you're looking for as plpgsql though.
Distribution of Postgres extensions is a challenging problem that we're working on over in https://github.com/tembo-io/trunk // https://pgt.dev/. One of the goals there is to make it easier to install extensions.
Distribution of Postgres extensions is a challenging problem that we're working on over in https://github.com/tembo-io/trunk // https://pgt.dev/. One of the goals there is to make it easier to install extensions.