var payload []byte // could be anything, including stringified json, etc
var salt []byte // random salt bytes. should be stored.

token := hwt.Sign(payload, salt)

var salt []byte // the same salt that's used for signing before
var token string

payload, ok := hwt.Check(token, salt)

if !ok {
  // not valid. not signed by us. don't do anything.
  return
}

// check passed. deal with <payload>