50.3. Streaming Replication Protocol Interface
The commands
CREATE_REPLICATION_SLOTslot_nameLOGICALoutput_pluginDROP_REPLICATION_SLOT[slot_nameWAIT]START_REPLICATION SLOTslot_nameLOGICAL ...
are used to create, drop, and stream changes from a replication slot, respectively. These commands are only available over a replication connection; they cannot be used via SQL. See Section 54.4 for details on these commands.
The command pg_recvlogical can be used to control logical decoding over a streaming replication connection. (It uses these commands internally.)