RS485 - each to each communication protocol

I'm looking for RS485 communication protocol where each device can send data to any other (each to each, no master)

Can You advice any library ?

Do you need a library ? Do you actually need RS485 ?

If you define the protocol for the transmission then you will know what to expect and how to parse it on the receiving end. As I understand it RS-485 only specifies electrical characteristics of the transmitter and the receiver. It does not specify a communications protocol, only the physical layer.

I’m using RS485 for communication. I’m looking for protocol to use - similar to ModBus for example - but I can’t use Modbus becasue it works as master slave.

I need to have each to each connection.