Class: Ask::Providers::Anthropic

Inherits:
Ask::Provider
  • Object
show all
Includes:
LLM::ProviderConfig, LLM::SSEBuffer
Defined in:
lib/ask/provider/anthropic.rb

Overview

Anthropic Claude API provider.

Class Method Summary collapse

Instance Method Summary collapse

Methods included from LLM::SSEBuffer

#each_sse_event, #init_sse_buffer

Constructor Details

#initialize(config = {}) ⇒ Anthropic

Returns a new instance of Anthropic.



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# File 'lib/ask/provider/anthropic.rb', line 10

def initialize(config = {})
  config = normalize_config(config)
  super(config)
  @http = build_http
end

Class Method Details

.capabilities ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 57

def capabilities
  {
    chat: true, streaming: true, tool_calls: true, vision: true,
    thinking: true, prompt_caching: true, structured_output: true
  }
end

.configuration_options ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 64

def configuration_options; %i[api_key api_base]; end

.configuration_requirements ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 65

def configuration_requirements; %i[api_key]; end

.slug ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 55

def slug; "anthropic"; end

Instance Method Details

#api_base ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 16

def api_base
  @config.api_base || "https://api.anthropic.com"
end

#build_request(messages, model:, tools: nil, temperature: nil, stream: nil, schema: nil, **params) ⇒ Object

--- Config transformation contract ---



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# File 'lib/ask/provider/anthropic.rb', line 70

def build_request(messages, model:, tools: nil, temperature: nil, stream: nil, schema: nil, **params)
  system_msgs, chat_msgs = messages.partition { |m| (m[:role] || m["role"]).to_s == "system" }
  prompt_caching = params.delete(:prompt_caching) || false

  payload = {
    model:,
    messages: chat_msgs.map { |m| format_message(m) },
    max_tokens: params.delete(:max_tokens) || 4096,
    stream: stream || false
  }

  if prompt_caching
    payload[:system] = format_system_with_caching(system_msgs, chat_msgs)
    # Mark the last user message for caching (required by Anthropic for conversation caching)
    if payload[:messages].any?
      last_user_idx = payload[:messages].rindex { |m| m[:role] == "user" }
      if last_user_idx
        content = payload[:messages][last_user_idx][:content]
        payload[:messages][last_user_idx][:content] = wrap_content_for_caching(content)
      end
    end
  else
    system_content = format_system_content(system_msgs)
    payload[:system] = system_content if system_content
  end

  tool_defs = format_tools(tools) if tools&.any?
  payload[:tools] = tool_defs if tool_defs
  payload[:temperature] = temperature if temperature
  payload.merge(params)
end

#chat(messages, model:, tools: nil, temperature: nil, stream: nil, schema: nil, **params, &block) ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 28

def chat(messages, model:, tools: nil, temperature: nil, stream: nil, schema: nil, **params, &block)
  msgs = messages.is_a?(Ask::Conversation) ? messages.to_a : messages
  payload = build_request(msgs, model:, tools:, temperature:, stream:, schema:, **params)
  if stream
    chat_stream(payload, model, &block)
  else
    chat_nonstream(payload, model)
  end
end

#embed(_texts, model: nil) ⇒ Object

Raises:

  • (Ask::CapabilityNotSupported) 


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# File 'lib/ask/provider/anthropic.rb', line 38

def embed(_texts, model: nil)
  raise Ask::CapabilityNotSupported, "Anthropic does not support embeddings"
end

#format_message(msg) ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 164

def format_message(msg)
  role = (msg[:role] || msg["role"]).to_s
  content = msg[:content] || msg["content"]

  if msg[:tool_calls] || msg["tool_calls"]
    tc = msg[:tool_calls] || msg["tool_calls"]
    return {
      role:,
      content:,
      tool_calls: tc.map { |t|
        {
          type: "tool_use",
          id: t[:id] || t["id"],
          name: t.dig(:function, :name) || t.dig("function", "name") || t[:name],
          input: parse_json(t.dig(:function, :arguments) || t.dig("function", "arguments") || t[:arguments] || "{}")
        }
      }.compact
    }.compact
  end

  if msg[:tool_call_id] || msg["tool_call_id"]
    return {
      role: "user",
      content: [{
        type: "tool_result",
        tool_use_id: msg[:tool_call_id] || msg["tool_call_id"],
        content: content || ""
      }]
    }
  end

  { role:, content: }.compact
end

#format_tools(tools) ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 154

def format_tools(tools)
  tools.map do |t|
    {
      name: t.respond_to?(:name) ? t.name : t[:name],
      description: t.respond_to?(:description) ? t.description : t[:description],
      input_schema: t.respond_to?(:parameters) ? t.parameters : (t[:parameters] || { type: "object", properties: {} })
    }
  end
end

#headers ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 20

def headers
  {
    "x-api-key" => @config.api_key,
    "anthropic-version" => "2023-06-01",
    "Content-Type" => "application/json"
  }
end

#list_models ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 42

def list_models
  response = @http.get("v1/models")
  return [] unless response.success?

  response.body["data"].map { |m| Ask::ModelInfo.new(id: m["id"], provider: slug) }
end

#parse_error(response) ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 49

def parse_error(response)
  body = response.body rescue nil
  body&.dig("error", "message") || body&.dig("error", "type")
end

#parse_response(body, model) ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 102

def parse_response(body, model)
  content_blocks = body["content"] || []
  text_content = content_blocks.select { |c| c["type"] == "text" }.map { |c| c["text"] }.join
  tool_blocks = content_blocks.select { |c| c["type"] == "tool_use" }
  thinking_blocks = content_blocks.select { |c| %w[thinking redacted_thinking].include?(c["type"]) }
  usage = body["usage"] || {}

  tool_calls = tool_blocks.map do |tb|
    { id: tb["id"], type: "function", name: tb["name"], arguments: JSON.generate(tb["input"]) }
  end

  metadata = {
    model: body["model"] || model,
    stop_reason: body["stop_reason"],
    stop_sequence: body["stop_sequence"],
    input_tokens: usage["input_tokens"],
    output_tokens: usage["output_tokens"],
    cache_creation_input_tokens: usage["cache_creation_input_tokens"],
    cache_read_input_tokens: usage["cache_read_input_tokens"],
    thinking: thinking_blocks.map { |b| b["thinking"] || b["text"] }.compact.join("\n"),
    raw: body
  }.compact

  text = text_content.empty? ? nil : text_content
  Ask::Message.new(role: :assistant, content: text, tool_calls: tool_calls.empty? ? nil : tool_calls, metadata:)
end

#parse_stream(raw, stream, model, &block) ⇒ Object 



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# File 'lib/ask/provider/anthropic.rb', line 129

def parse_stream(raw, stream, model, &block)
  each_sse_event(raw) do |data|
    parsed = JSON.parse(data) rescue next

    case parsed["type"]
    when "content_block_delta"
      delta = parsed.dig("delta")
      next unless delta

      chunk = Ask::Chunk.new(content: delta["text"])
      stream.add(chunk)
      yield chunk if block_given?
    when "message_stop"
      usage = parsed["usage"] || parsed["message"]&.dig("usage")
      if usage
        chunk = Ask::Chunk.new(finish_reason: "stop", usage:)
        stream.add(chunk)
        yield chunk if block_given?
      end
    when "message_start"
      # Handled by content_block_start instead
    end
  end
end