class LittleGhost::Providers::Anthropic

Connects a Model to Anthropic’s Messages API.

Requests send messages, Tool definitions, attachments, and model settings to the configured Anthropic endpoint. The adapter reads its credential from trusted configuration, honors cancellation and deadlines, and emits LittleGhost StreamEvents. HTTP and response-shape failures become ProviderError subclasses. It uses the built-in HTTP client and does not require Anthropic’s SDK.

Attributes

model [R]

Provider-owned model identifier.

Public Class Methods

new (api_key:, model:, base_url: DEFAULT_BASE_URL, api_version: "2023-06-01", open_timeout: 10, read_timeout: 120, max_response_bytes: Support::HTTPClient::DEFAULT_MAX_RESPONSE_BYTES, transport: nil, **)

Source

# File lib/little_ghost/providers/anthropic.rb, line 29
def initialize(api_key:, model:, base_url: DEFAULT_BASE_URL, api_version: "2023-06-01",
  open_timeout: 10, read_timeout: 120, max_response_bytes: Support::HTTPClient::DEFAULT_MAX_RESPONSE_BYTES,
  transport: nil, **)
  raise CredentialError, "Anthropic api_key is required" if api_key.to_s.empty?

  @api_key = api_key
  @api_version = api_version
  @model = model
  @transport = transport || Support::HTTPClient.new(base_url:, open_timeout:, read_timeout:, max_response_bytes:)
end

Creates an Anthropic Messages client for model.

request_options ()

Source

# File lib/little_ghost/providers/anthropic.rb, line 21
def self.request_options = %i[max_response_bytes open_timeout read_timeout].freeze

Request policy supported by the Anthropic HTTP client.

Public Instance Methods

capabilities (metadata: {})

Source

# File lib/little_ghost/providers/anthropic.rb, line 67
def capabilities(metadata: {})
  parameters = metadata[:supported_parameters]
  ModelCapabilities.new(
    native_structured_output: parameters&.include?("structured_outputs"),
    tools: true,
    tool_choice: true,
    supported_parameters: parameters
  )
end

Reports tool and structured-output support from model metadata.

stream (request) { |event| ... }

Source

# File lib/little_ghost/providers/anthropic.rb, line 41
def stream(request)
  return enum_for(__method__, request) unless block_given?

  parser = Support::SSEParser.new
  normalizer = Normalizer.new(model:)
  @transport.stream(
    path: "messages",
    headers: {
      "x-api-key" => @api_key,
      "anthropic-version" => @api_version,
      "content-type" => "application/json",
      "accept" => "text/event-stream"
    },
    body: JSON.generate(request_body(request)),
    cancellation_token: request.cancellation_token,
    deadline: request.deadline
  ) do |chunk|
    parser.<<(chunk).each { |data| normalizer.consume(JSON.parse(data)).each { |event| yield event } }
  end
  parser.finish.each { |data| normalizer.consume(JSON.parse(data)).each { |event| yield event } }
  normalizer.finish.each { |event| yield event }
rescue JSON::ParserError => error
  raise ProtocolError, "Anthropic returned invalid JSON: #{error.message}"
end

Streams normalized events for request.