ESPHome gives makers a network path to serial equipment. One component carries a device’s physical serial port over a TCP network connection; another presents that network stream as a serial port that existing ESPHome components can use. Both copy the data unchanged in each direction.
Bascht74 supplies client and server modes, with each listening bridge accepting one connected peer. An optional list limits connections to specified IPv4 addresses or networks; leaving it out accepts any address. The connection carries raw data without encryption or password authentication. J. Nick Koston reviewed the implementation and its companion guides.