message Handshake1 {
    // protocolVersion determines compatibility between peers
    optional string protocolVersion = 1; // semver

    // agentVersion is like a UserAgent string in browsers, or client version in bittorrent
    // includes the client name and client. e.g.   "go-ipfs/0.1.0"
    optional string agentVersion = 2; // semver 

    // we'll have more fields here later.
}