Class: Durable::Llm::Providers::Anthropic

Inherits:
Base
  • Object
show all
Defined in:
lib/durable/llm/providers/anthropic.rb

Overview

Anthropic provider for accessing Claude language models through their API.

This provider implements the Durable::Llm::Providers::Base interface to provide completion and streaming capabilities for Anthropic’s Claude models including Claude 3.5 Sonnet, Claude 3 Opus, and Claude 3 Haiku. It handles authentication via API keys, supports system messages, and provides comprehensive error handling for various Anthropic API error conditions.

Key features:

  • Message-based chat completions with multi-turn conversations

  • Real-time streaming responses for interactive applications

  • System message support for setting context

  • Automatic model listing from predefined supported models

  • Comprehensive error handling with specific exception types

Examples:

Basic completion

provider = Durable::Llm::Providers::Anthropic.new(api_key: 'your-api-key')
response = provider.completion(
  model: 'claude-3-5-sonnet-20240620',
  messages: [{ role: 'user', content: 'Hello, world!' }]
)
puts response.choices.first.to_s

Completion with system message

response = provider.completion(
  model: 'claude-3-5-sonnet-20240620',
  messages: [
    { role: 'system', content: 'You are a helpful assistant.' },
    { role: 'user', content: 'Hello!' }
  ]
)

Streaming response

provider.stream(model: 'claude-3-5-sonnet-20240620', messages: messages) do |chunk|
  print chunk.to_s
end

See Also:

Defined Under Namespace

Classes: AnthropicChoice, AnthropicMessage, AnthropicResponse, AnthropicStreamChoice, AnthropicStreamDelta, AnthropicStreamResponse

Constant Summary collapse

BASE_URL = 
'https://api.anthropic.com'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

options, #stream?

Constructor Details

#initialize(api_key: nil) ⇒ Anthropic

Initializes a new Anthropic provider instance.

Parameters:

  • api_key (String, nil) (defaults to: nil) —

    The Anthropic API key. If nil, uses default_api_key



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# File 'lib/durable/llm/providers/anthropic.rb', line 68

def initialize(api_key: nil)
  super()
  @api_key = api_key || default_api_key

  @conn = Faraday.new(url: BASE_URL) do |faraday|
    faraday.request :json
    faraday.response :json
    faraday.adapter Faraday.default_adapter
  end
end

Instance Attribute Details

#api_key ⇒ String?

Returns The API key used for authentication with Anthropic.

Returns:

  • (String, nil) —

    The API key used for authentication with Anthropic



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# File 'lib/durable/llm/providers/anthropic.rb', line 62

def api_key
  @api_key
end

Class Method Details

.models ⇒ Array<String>

Retrieves the list of supported Claude models.

Returns:

  • (Array<String>) —

    Array of supported Claude model identifiers



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# File 'lib/durable/llm/providers/anthropic.rb', line 129

def self.models
  ['claude-3-5-sonnet-20240620', 'claude-3-opus-20240229', 'claude-3-haiku-20240307']
end

.stream? ⇒ Boolean

Returns True, indicating this provider supports streaming.

Returns:

  • (Boolean) —

    True, indicating this provider supports streaming



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# File 'lib/durable/llm/providers/anthropic.rb', line 134

def self.stream?
  true
end

Instance Method Details

#completion(options) ⇒ AnthropicResponse

Performs a completion request to Anthropic’s messages API.

Parameters:

  • options (Hash) —

    The completion options

Options Hash (options):

  • :model (String) —

    The Claude model to use

  • :messages (Array<Hash>) —

    Array of message objects with role and content

  • :max_tokens (Integer) —

    Maximum number of tokens to generate (default: 1024)

  • :temperature (Float) —

    Sampling temperature between 0 and 1

  • :system (String) —

    System message to set context

Returns:

Raises:



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# File 'lib/durable/llm/providers/anthropic.rb', line 92

def completion(options)
  # Convert symbol keys to strings for consistency
  options = options.transform_keys(&:to_s)

  # Ensure max_tokens is set
  options['max_tokens'] ||= 1024

  # Handle system message separately as Anthropic expects it as a top-level parameter
  system_message = nil
  messages = options['messages']&.dup || []
  if messages.first && (messages.first['role'] || messages.first[:role]) == 'system'
    system_message = messages.first['content'] || messages.first[:content]
    messages = messages[1..] || []
  end

  request_body = options.merge('messages' => messages)
  request_body['system'] = system_message if system_message

  response = @conn.post('/v1/messages') do |req|
    req.headers['x-api-key'] = @api_key
    req.headers['anthropic-version'] = '2023-06-01'
    req.body = request_body
  end

  handle_response(response)
end

#default_api_key ⇒ String?

Returns The default API key for Anthropic, or nil if not configured.

Returns:

  • (String, nil) —

    The default API key for Anthropic, or nil if not configured



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# File 'lib/durable/llm/providers/anthropic.rb', line 56

def default_api_key
  Durable::Llm.configuration.anthropic&.api_key || ENV['ANTHROPIC_API_KEY']
end

#embedding(model:, input:, **options) ⇒ Object

Performs an embedding request (not supported by Anthropic).

Parameters:

  • model (String) —

    The model to use for generating embeddings

  • input (String, Array<String>) —

    The input text(s) to embed

  • options (Hash) —

    Additional options for the embedding request

Raises:

  • (NotImplementedError) —

    Anthropic does not provide embedding APIs



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# File 'lib/durable/llm/providers/anthropic.rb', line 144

def embedding(model:, input:, **options)
  raise NotImplementedError, 'Anthropic does not provide embedding APIs'
end

#models ⇒ Array<String>

Retrieves the list of available models for this provider instance.

Returns:

  • (Array<String>) —

    The list of available Claude model names



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# File 'lib/durable/llm/providers/anthropic.rb', line 122

def models
  self.class.models
end

#stream(options) {|AnthropicStreamResponse| ... } ⇒ Object

Performs a streaming completion request to Anthropic’s messages API.

Parameters:

  • options (Hash) —

    The stream options (same as completion plus stream: true)

Yields:

Returns:

  • (Object) —

    The final response object

Raises:



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# File 'lib/durable/llm/providers/anthropic.rb', line 157

def stream(options)
  options = options.transform_keys(&:to_s)
  options['stream'] = true

  # Handle system message separately
  system_message = nil
  messages = options['messages']&.dup || []
  if messages.first && (messages.first['role'] || messages.first[:role]) == 'system'
    system_message = messages.first['content'] || messages.first[:content]
    messages = messages[1..] || []
  end

  request_body = options.merge('messages' => messages)
  request_body['system'] = system_message if system_message

  response = @conn.post('/v1/messages') do |req|
    req.headers['x-api-key'] = @api_key
    req.headers['anthropic-version'] = '2023-06-01'
    req.headers['Accept'] = 'text/event-stream'

    req.body = request_body

    user_proc = proc do |chunk, _size, _total|
      yield AnthropicStreamResponse.new(chunk)
    end

    req.options.on_data = to_json_stream(user_proc: user_proc)
  end

  handle_response(response)
end