syntax = "proto3";

package ens;

enum Error {
    Unknown = 0;
    ConnectionLimitReached = 1;
    ServerMaintenance = 2;        // Only this error type can cause automatic recconection to a different server
    Unauthenticated = 3;
    Superseded = 4;
}

message ConnectionErrorRequest {}

message ConnectionError {
    Error code = 1;
    optional string additional_info = 2;
}

message ChallengeRequest {}

message ChallengeResponse {
    string challenge = 1;
}

service Login {
    rpc GetChallenge(ChallengeRequest) returns (ChallengeResponse);
}

service ENS {
    rpc ConnectionErrors(ConnectionErrorRequest) returns (stream ConnectionError);
}