# `Nous.Messages.Anthropic`
[🔗](https://github.com/nyo16/nous/blob/v0.17.1/lib/nous/messages/anthropic.ex#L1)

Anthropic format message conversion.

Handles conversion between internal Message structs and Anthropic API format.

# `from_messages`

```elixir
@spec from_messages([map()]) :: [Nous.Message.t()]
```

Convert Anthropic format messages to internal Message structs.

# `from_response`

```elixir
@spec from_response(map()) :: Nous.Message.t()
```

Parse Anthropic response into a Message.

## Examples

    iex> response = %{"content" => [%{"type" => "text", "text" => "Hello"}], "model" => "claude-3"}
    iex> message = Messages.Anthropic.from_response(response)
    iex> {message.role, message.content}
    {:assistant, "Hello"}

# `parse_usage`

```elixir
@spec parse_usage(map() | nil) :: Nous.Usage.t()
```

Parse an Anthropic-format usage map into a `%Nous.Usage{}` struct.

Used by both the non-streaming response parser and the streaming normalizer
(`message_delta` carries incremental output tokens).

# `to_format`

```elixir
@spec to_format([Nous.Message.t()]) :: {String.t() | nil, [map()]}
```

Convert messages to Anthropic format.

Returns `{system_prompt, messages}` where system prompt is extracted
and combined, and messages are converted to Anthropic format.

## Examples

    iex> messages = [Message.system("Be helpful"), Message.user("Hello")]
    iex> Messages.Anthropic.to_format(messages)
    {"Be helpful", [%{"role" => "user", "content" => "Hello"}]}

---

*Consult [api-reference.md](api-reference.md) for complete listing*