Structured output: extract a validated Ecto struct from an LLM.

The Elixir analogue of "Zod schema → validated object" is "Ecto schema → validated changeset". You define an embedded schema with a changeset/2, and extract/3 prompts a provider for JSON, casts it through the changeset, and — on a parse or validation error — feeds the problem back to the model and retries (up to :max_retries).

Works over any AgentSea.Provider (so requests can run through the gateway) and needs no network in tests.

Example

defmodule Person do
  use Ecto.Schema
  import Ecto.Changeset

  @primary_key false
  embedded_schema do
    field :name, :string
    field :age, :integer
  end

  def changeset(struct, params) do
    struct
    |> cast(params, [:name, :age])
    |> validate_required([:name, :age])
    |> validate_number(:age, greater_than: 0)
  end
end

{:ok, %Person{}} =
  AgentSea.Structured.extract(Person, "Ada Lovelace, 36",
    provider: {AgentSea.Providers.Anthropic, []},
    model: "claude-opus-4-8"
  )