Extends an Ash type with Lua-facing metadata and encoding.

Add use AshLua.Type to a custom type module (typically alongside use Ash.Type or use Ash.Type.NewType) and implement any of the optional callbacks.

type_name/0

Controls the name surfaced in generated documentation (AshLua.Docs) for that type.

defmodule MyApp.Slug do
  use Ash.Type.NewType, subtype_of: :string
  use AshLua.Type

  @impl AshLua.Type
  def type_name, do: "slug"
end

When a module does not implement type_name/0, the default name is derived from the module itself: the last module segment, with Ash.Type. prefixed modules underscored (Ash.Type.UUID → "uuid", Ash.Type.Boolean → "boolean").

to_lua/2

Controls how a value of this type is encoded for the Lua side. Return any Lua-friendly value (maps/lists/strings/numbers/booleans/nil) — it is run through the standard normalization afterwards, so nested Decimal/Date/ etc. are still handled for you.

defmodule MyApp.Money do
  use Ash.Type.NewType, subtype_of: :integer
  use AshLua.Type

  @impl AshLua.Type
  def to_lua(cents, _constraints) do
    %{"cents" => cents}
  end
end

When a type does not implement to_lua/2, AshLua falls back to its built-in defaults: special handling for the Ash builtin types that need it (CiString, Decimal, dates/times, durations), and a plain JSON-style encoding for everything else.