Anthropix (Anthropix v0.6.2)

Anthropix

License

Anthropix is an open-source Elixir client for the Anthropic API, providing a simple and convenient way to integrate Claude, Anthropic's powerful language model, into your applications.

✅ API client fully implementing the Anthropic API
🧰 Tool use (function calling)
🧠 Extended thinking
⚡ Prompt caching
📦 Message batching (Anthropix.Batch)
🛜 Streaming API requests
- Stream to an Enumerable
- Or stream messages to any Elixir process

Installation

The package can be installed by adding anthropix to your list of dependencies in mix.exs.

def deps do
  [
    {:anthropix, "~> 0.6.2"}
  ]
end

Quickstart

Beta features

Anthropic frequently ship new features under a beta flag, requiring headers to be added to your requests to take advantage of the feature.

If required, beta headers can be added with init/2.

client = Anthropix.init(beta: ["output-128k-2025-02-19"])

Initiate a client.

See Anthropix.init/2.

iex> client = Anthropix.init(api_key)

Chat with Claude

See Anthropix.chat/2.

iex> messages = [
...>   %{role: "user", content: "Why is the sky blue?"},
...>   %{role: "assistant", content: "Due to rayleigh scattering."},
...>   %{role: "user", content: "How is that different than mie scattering?"},
...> ]

iex> Anthropix.chat(client, [
...>   model: "claude-3-opus-20240229",
...>   messages: messages,
...> ])
{:ok, %{"content" => [%{
  "type" => "text",
  "text" => "Mie scattering affects all wavelengths similarly, while Rayleigh favors shorter ones."
}], ...}}

Streaming

A streaming request can be initiated by setting the :stream option.

When :stream is true a lazy Enumerable.t/0 is returned which can be used with any Stream functions.

iex> {:ok, stream} = Anthropix.chat(client, [
...>   model: "claude-3-opus-20240229",
...>   messages: messages,
...>   stream: true,
...> ])
{:ok, #Function<52.53678557/2 in Stream.resource/3>}

iex> stream
...> |> Stream.each(&update_ui_with_chunk/1)
...> |> Stream.run()
:ok

Because the above approach builds the Enumerable.t/0 by calling receive, using this approach inside GenServer callbacks may cause the GenServer to misbehave. Setting the :stream option to a pid/0 returns a Task.t/0 which will send messages to the specified process.

Summary

Types

client()

Client struct

content_block()

Message content block.

content_media()

content_text()

content_tool_result()

content_tool_use()

input_schema()

JSON schema for the tool input shape.

message()

Chat message

response()

Client response

tool()

Tool.

Functions

chat(client, params \\ [])

Chat with Claude. Send a list of structured input messages with text and/or image content, and Claude will generate the next message in the conversation.

init()

Calling init/1 without passing an API key, creates a new Anthropix API client using the API key set in your application's config.

init(opts)

init(api_key, opts \\ [])

Calling init/2 with an API key creates a new Anthropix API client, using the given API key. Optionally, a keyword list of options can be passed through to Req.new/1.

Types

client()

@type client() :: %Anthropix{req: Req.Request.t()}

Client struct

content_block()

@type content_block() ::
  content_text() | content_media() | content_tool_use() | content_tool_result()

Message content block.

content_media()

@type content_media() :: %{
  type: String.t(),
  source: %{type: String.t(), media_type: String.t(), data: String.t()}
}

content_text()

@type content_text() :: %{type: String.t(), text: String.t()}

content_tool_result()

@type content_tool_result() :: %{
  type: String.t(),
  tool_use_id: String.t(),
  content: %{optional(String.t()) => String.t()}
}

content_tool_use()

@type content_tool_use() :: %{
  type: String.t(),
  id: String.t(),
  name: String.t(),
  input: %{optional(String.t()) => String.t()}
}

input_schema()

@type input_schema() :: %{
  :type => String.t(),
  :properties => %{
    optional(String.t()) => %{
      optional(:enum) => [String.t()],
      type: String.t(),
      description: String.t()
    }
  },
  optional(:required) => [String.t()]
}

JSON schema for the tool input shape.

message()

@type message() :: %{role: String.t(), content: String.t() | [content_block()]}

Chat message

A chat message is a map/0 with the following fields:

:role (String.t/0) - Required. The role of the message, either user or assistant.
:content - Required. Message content, either a single string or an array of content blocks.

response()

@type response() :: {:ok, map() | Enumerable.t() | Task.t()} | {:error, term()}

Client response

tool()

@type tool() :: %{
  name: String.t(),
  description: String.t(),
  input_schema: input_schema()
}

Tool.

A chat tool is a map/0 with the following fields:

:name (String.t/0) - Required. Name of the tool.
:description (String.t/0) - Required. Description of the tool
:input_schema - Required. JSON schema for the tool input shape that the model will produce in tool_use output content blocks.
:cache_control - Cache-control parameter.

Functions

chat(client, params \\ [])

@spec chat(
  client(),
  keyword()
) :: response()

Chat with Claude. Send a list of structured input messages with text and/or image content, and Claude will generate the next message in the conversation.

Options

:model (String.t/0) - Required. The model that will complete your prompt.
:messages (list of map/0) - Required. Input messages.
:system - System prompt.
:thinking (map/0) - Enable thinking mode and the budget of tokens to use.
- :type
- :budget_tokens (non_neg_integer/0)
:max_tokens (integer/0) - The maximum number of tokens to generate before stopping. The default value is 4096.
:metadata - A map describing metadata about the request.
:stop_sequences (list of String.t/0) - Custom text sequences that will cause the model to stop generating.
:stream - Whether to incrementally stream the response using server-sent events. The default value is false.
:temperature (float/0) - Amount of randomness injected into the response.
:tools (list of map/0) - A list of tools the model may call.
:tool_choice (map/0) - How to use the provided tools.
- :type (String.t/0) - Required. One of auto, any or tool.
- :name (String.t/0) - The name of the tool to use.
- :disable_parallel_tool_use (boolean/0)
:top_k (integer/0) - Only sample from the top K options for each subsequent token.
:top_p (float/0) - Amount of randomness injected into the response.

Message structure

Each message is a map with the following fields:

:role (String.t/0) - Required. The role of the message, either user or assistant.
:content - Required. Message content, either a single string or an array of content blocks.

Tool structure

Each tool is a map with the following fields:

:name (String.t/0) - Required. Name of the tool.
:description (String.t/0) - Required. Description of the tool
:input_schema - Required. JSON schema for the tool input shape that the model will produce in tool_use output content blocks.
:cache_control - Cache-control parameter.

Examples

iex> messages = [
...>   %{role: "user", content: "Why is the sky blue?"},
...>   %{role: "assistant", content: "Due to rayleigh scattering."},
...>   %{role: "user", content: "How is that different than mie scattering?"},
...> ]

iex> Anthropix.chat(client, [
...>   model: "claude-3-opus-20240229",
...>   messages: messages,
...> ])
{:ok, %{"content" => [%{
  "type" => "text",
  "text" => "Mie scattering affects all wavelengths similarly, while Rayleigh favors shorter ones."
}], ...}}

# Passing true to the :stream option initiates an async streaming request.
iex> Anthropix.chat(client, [
...>   model: "claude-3-opus-20240229",
...>   messages: messages,
...>   stream: true,
...> ])
{:ok, #Function<52.53678557/2 in Stream.resource/3>}

init()

@spec init() :: client()

Calling init/1 without passing an API key, creates a new Anthropix API client using the API key set in your application's config.

config :anthropix, :api_key, "sk-ant-your-key"

If given, a keyword list of options will be passed to Req.new/1.

Examples

iex> client = Anthropix.init()
%Anthropix{}

init(opts)

@spec init(keyword()) :: client()

init(api_key, opts \\ [])

@spec init(
  String.t(),
  keyword()
) :: client()

Calling init/2 with an API key creates a new Anthropix API client, using the given API key. Optionally, a keyword list of options can be passed through to Req.new/1.

Examples

iex> client = Anthropix.init("sk-ant-your-key", receive_timeout: :infinity)
%Anthropix{}