The adapter specification.

Adapter is a module that denormalize request data stored in Tesla.Env in order to make request with lower level http client (e.g. :httpc or :hackney) and normalize response data in order to store it back to Tesla.Env. It has to implement Tesla.Adapter.call/2.

Writing custom adapter

Create a module implementing Tesla.Adapter.call/2.

See Tesla.Adapter.call/2 for details.

Examples

defmodule MyProject.CustomAdapter do
  alias Tesla.Multipart

  @behaviour Tesla.Adapter

  @override_defaults [follow_redirect: false]

  @impl Tesla.Adapter
  def call(env, opts) do
    opts = Tesla.Adapter.opts(@override_defaults, env, opts)

    with {:ok, {status, headers, body}} <- request(env.method, env.body, env.headers, opts) do
      {:ok, normalize_response(env, status, headers, body)}
    end
  end

  defp request(_method, %Stream{}, _headers, _opts) do
    {:error, "stream not supported by adapter"}
  end

  defp request(_method, %Multipart{}, _headers, _opts) do
    {:error, "multipart not supported by adapter"}
  end

  defp request(method, body, headers, opts) do
    :lower_level_http.request(method, body, denormalize_headers(headers), opts)
  end

  defp denormalize_headers(headers), do: ...
  defp normalize_response(env, status, headers, body), do: %Tesla.Env{env | ...}
end