syntax = "proto3";

enum Action {
    ACTION_SEND = 0;
    ACTION_GET = 1;
    ACTION_INBOX = 2;
}

message Mex {
    string from = 1;
    string content = 2;
    int64 at = 3;
}

message RespData {
    string error = 1;
    repeated Mex messages = 2;
}

message ReqData {
    Action action = 1;
    string content = 2;
    string from = 3;
    string to = 4;
}