Envoy's xDS APIs work with snapshots of configuration data that are compiled externally and sent to Envoy.
HAProxy's API looks like more of a transactional RPC API and HAProxy manages the configuration internally.
HAProxy's API looks like more of a transactional RPC API and HAProxy manages the configuration internally.
Getting an entire snapshot of configuration data is quite compatible with this, since then the explicit use of transactions is not necessary and the dataplane can take care of it on its own.