       when generating the encryption and signing keys. Defaults to `:sha256`
     * `:signed_at` - set the timestamp of the token in seconds.
       Defaults to `System.system_time(:second)`
-    * `:max_age` - the default maximum age of the token. Defaults to
-      86400 seconds (1 day) and it may be overridden on verify/4.
-
-  """
+
+  """
+  @spec sign(context, binary, term, [shared_opt | signed_at_opt]) :: binary
   def sign(context, salt, data, opts \\ []) when is_binary(salt) do
     context
     |> get_key_base()


  require Logger

  @doc """
  Encodes  and signs data into a token you can send to clients.

  ## Options


      Defaults to `System.system_time(:second)`

  """
  @spec encrypt(context, binary, term, [shared_opt | signed_at_opt]) :: binary
  def encrypt(context, secret, data, opts \\ []) when is_binary(secret) do
    context
    |> get_key_base()
