Anthropic adapter added

lib/instructor/adapters/anthropic.ex

@@ -0,0 +1,109 @@
+defmodule Instructor.Adapters.Anthropic do
+  @moduledoc """
+  Documentation for `Instructor.Adapters.Anthropic`.
+  """
+@headers
+
+  @behaviour Instructor.Adapter
+
+  @impl true
+  def chat_completion(params, config) do
+    config = if config, do: config, else: config()
+
+    # Peel off instructor only parameters
+    {_, params} = Keyword.pop(params, :response_model)
+    {_, params} = Keyword.pop(params, :validation_context)
+    {_, params} = Keyword.pop(params, :max_retries)
+    {_, params} = Keyword.pop(params, :mode)
+    stream = Keyword.get(params, :stream, false)
+    params = Enum.into(params, %{})
+
+    if stream do
+      do_streaming_chat_completion(params, config)
+    else
+      do_chat_completion(params, config)
+    end
+  end
+
+  defp do_streaming_chat_completion(params, config) do
+    pid = self()
+    options = http_options(config)
+
+    Stream.resource(
+      fn ->
+        Task.async(fn ->
+          options =
+            Keyword.merge(options,
+              json: params,
+              auth: {:bearer, api_key(config)},
+              into: fn {:data, data}, {req, resp} ->
+                chunks =
+                  data
+                  |> String.split("\n")
+                  |> Enum.filter(fn line ->
+                    String.starts_with?(line, "data: {")
+                  end)
+                  |> Enum.map(fn line ->
+                    line
+                    |> String.replace_prefix("data: ", "")
+                    |> Jason.decode!()
+                  end)
+
+                for chunk <- chunks do
+                  send(pid, chunk)
+                end
+
+                {:cont, {req, resp}}
+              end
+            )
+
+          Req.post!(url(config), options)
+          send(pid, :done)
+        end)
+      end,
+      fn task ->
+        receive do
+          :done ->
+            {:halt, task}
+
+          data ->
+            {[data], task}
+        after
+          15_000 ->
+            {:halt, task}
+        end
+      end,
+      fn task -> Task.await(task) end
+    )
+  end
+
+  defp do_chat_completion(params, config) do
+    options = Keyword.merge(http_options(config), json: params, headers: [
+    {"x-api-key", System.get_env("ANTHROPIC_API_KEY")},
+    {"anthropic-version", "2023-06-01"},
+    {"content-type", "application/json"},
+  ])
+    response = Req.post!(url(config), options)
+
+    case response.status do
+      200 -> {:ok, response.body}
+      _ -> {:error, response.body}
+    end
+  end
+
+  defp url(config), do: api_url(config) <> "/v1/messages"
+  defp api_url(config), do: Keyword.fetch!(config, :api_url)
+  defp api_key(config), do: Keyword.fetch!(config, :api_key)
+  defp http_options(config), do: Keyword.fetch!(config, :http_options)
+
+  defp config() do
+    base_config = Application.get_env(:instructor, :anthropic, [])
+
+    default_config = [
+      api_url: "https://api.anthropic.com",
+      http_options: [receive_timeout: 60_000]
+    ]
+
+    Keyword.merge(default_config, base_config)
+  end
+end