Class: Legion::Extensions::Llm::Anthropic::Translator

Inherits:
Object
  • Object
show all
Includes:
Logging::Helper
Defined in:
lib/legion/extensions/llm/anthropic/translator.rb

Overview

Canonical provider translator for Anthropic Messages API. Implements the provider-boundary contract: canonical to Anthropic wire format. Extracted from Provider render_format/parse methods - behaviour preserved, not rewritten.

Constant Summary collapse

CAPABILITIES =

Anthropic-specific capabilities per the Phase 3 design.

{
  provider:              'anthropic',
  # Thinking lifecycle: open thinking -> delta -> signature_delta -> close.
  # Signature required alongside thinking content on Anthropic.
  thinking:              :signature_lifecycle,
  # Anthropic supports assistant prefill (sending partial assistant message
  # to bias completion direction) - used in mid-stream failover (G6).
  assistant_prefill:     true,
  # Streaming support.
  streaming:             true,
  # Tool calls are first-class (tool_use content blocks).
  tool_calls:            :native,
  # System prompt as array of content blocks.
  system_content_blocks: true,
  # Supported params (G18). Unsupported params dropped with debug log.
  supported_params:      %i[
    max_tokens temperature stop_sequences seed response_format
  ].freeze
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(config = {}) ⇒ Translator

Returns a new instance of Translator.



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# File 'lib/legion/extensions/llm/anthropic/translator.rb', line 39

def initialize(config = {}) = @config = config

Instance Method Details

#capabilities ⇒ Object 



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# File 'lib/legion/extensions/llm/anthropic/translator.rb', line 37

def capabilities = CAPABILITIES

#config ⇒ Object 



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# File 'lib/legion/extensions/llm/anthropic/translator.rb', line 38

def config = @config || {}

#parse_chunk(raw) ⇒ Object

Parse chunk: raw Anthropic SSE event to Canonical::Chunk. Real Anthropic events use top-level types like content_block_delta, message_delta, content_block_start; the delta kind is nested inside delta.type.



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# File 'lib/legion/extensions/llm/anthropic/translator.rb', line 112

def parse_chunk(raw)
  return nil unless raw.is_a?(Hash) && (raw.key?(:type) || raw.key?('type'))

  type = (raw[:type] || raw['type']).to_s
  delta = raw[:delta] || raw['delta'] || {}
  delta = {} unless delta.is_a?(Hash)
  delta_type = (delta[:type] || delta['type']).to_s

  case type
  when 'content_block_delta'
    parse_content_block_delta(raw, delta, delta_type)
  when 'content_block_start'
    parse_content_block_start(raw)
  when 'message_start'
    parse_message_start(raw)
  when 'message_delta'
    parse_message_delta(raw, delta)
  when 'message_stop'
    Canonical::Chunk.done(
      request_id:  raw[:request_id] || '',
      stop_reason: map_stop_reason(delta[:stop_reason] || delta['stop_reason'])
    )
  when 'text_delta'
    Canonical::Chunk.text_delta(
      delta:       extract_delta(raw, 'text_delta'),
      request_id:  raw[:request_id],
      block_index: raw[:block_index] || raw['index']
    )
  when 'thinking_delta'
    sig_from_delta = (delta[:signature] || delta['signature'] if delta.any?)
    Canonical::Chunk.thinking_delta(
      delta:       extract_delta(raw, 'thinking_delta'),
      request_id:  raw[:request_id],
      block_index: raw[:block_index] || raw['index'],
      signature:   raw[:signature] || raw['signature'] || sig_from_delta
    )
  when 'tool_call_delta'
    tc = extract_tool_call_from_chunk(raw)
    return nil unless tc

    Canonical::Chunk.tool_call_delta(
      tool_call:   tc,
      request_id:  raw[:request_id],
      block_index: raw[:block_index] || raw['index']
    )
  when 'error'
    Canonical::Chunk.error_chunk(
      error:      raw[:error] || raw['error'] || 'unknown',
      request_id: raw[:request_id] || '',
      metadata:   raw[:metadata] || raw['metadata'] || {}
    )
  when 'done'
    usage = (Canonical::Usage.from_hash(raw[:usage] || raw['usage'] || {}) if raw[:usage] || raw['usage'])
    Canonical::Chunk.done(
      request_id:  raw[:request_id] || '',
      usage:       usage,
      stop_reason: map_stop_reason(raw[:stop_reason] || raw['stop_reason'])
    )
  else
    log.debug("[anthropic translator] ignoring unknown chunk type: #{type.inspect}")
    nil
  end
rescue StandardError => e
  handle_exception(e, level: :debug, handled: true, operation: 'anthropic.translator.parse_chunk')
  Canonical::Chunk.error_chunk(
    error:      "#{e.class}: #{e.message}",
    request_id: raw[:request_id] || ''
  )
end

#parse_response(wire) ⇒ Object

Parse: Anthropic wire Hash to Canonical::Response. Accepts both Anthropic wire format (content: array of blocks) and canonical form (text: string) for conformance kit compatibility.



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# File 'lib/legion/extensions/llm/anthropic/translator.rb', line 83

def parse_response(wire)
  # If the wire has canonical 'text' key, pass through using Canonical::Response factory.
  return Canonical::Response.from_hash(wire) if wire.key?(:text) || wire.key('text')

  content = Array(wire[:content] || wire['content'] || [])
  usage = wire[:usage] || wire['usage'] || {}
  raw_usage = parse_usage(usage)

  text = extract_text(content)
  thinking = extract_thinking(content)
  tool_calls = extract_tool_calls(content)
  stop_reason = map_stop_reason(wire[:stop_reason] || wire['stop_reason'])
  model = wire[:model] || wire['model']

  Canonical::Response.build(
    text:        text,
    thinking:    thinking,
    tool_calls:  tool_calls,
    usage:       raw_usage,
    stop_reason: stop_reason,
    model:       model,
    routing:     {},
    metadata:    wire.except(:content, :usage, :stop_reason, :model).compact
  )
end

#render_request(canonical_request) ⇒ Object

Render: Canonical::Request to Anthropic wire Hash.



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# File 'lib/legion/extensions/llm/anthropic/translator.rb', line 42

def render_request(canonical_request)
  msgs = canonical_request.messages || []
  system_messages, chat_messages = msgs.partition { |msg| msg.role == :system }

  system_parts = if canonical_request.system
                   render_system_string(canonical_request.system)
                 else
                   render_system_content(system_messages)
                 end
  message_parts = render_messages(chat_messages, thinking: thinking_enabled?(canonical_request))
  tools = render_tools(canonical_request.tools)
  tool_choice = render_tool_choice(canonical_request.tool_choice)
  model_id = canonical_request.metadata&.dig(:model) || 'claude-sonnet-4'

  base = {
    model:       model_id,
    messages:    message_parts,
    stream:      canonical_request.stream,
    system:      system_parts,
    temperature: canonical_request.params&.temperature
  }.compact

  params = canonical_request.params
  if params
    base[:max_tokens] = params.max_tokens
    base[:stop_sequences] = params.stop_sequences
    base[:seed] = params.seed
    drop_unsupported_params(params)
    base[:response_format] = render_response_format(params.response_format)
  end

  base[:thinking] = render_thinking_config(canonical_request) if thinking_enabled?(canonical_request)
  base[:tools] = tools if tools && !tools.empty?
  base[:tool_choice] = tool_choice if tool_choice
  base[:max_tokens] ||= canonical_request.metadata&.dig(:default_max_tokens) || settings_default_max_tokens

  base.compact
end