Class: Boxcars::ToolTrain

Inherits:
Train show all
Defined in:
lib/boxcars/train/tool_train.rb

Overview

A Train runtime that uses native LLM tool-calling instead of text ReAct parsing.

Direct Known Subclasses

StationAgent

Defined Under Namespace

Classes: MessagePrompt

Constant Summary collapse

DEFAULT_NAME = 
"Tool Calling Train"
DEFAULT_DESCRIPTION = 
"Train that uses native tool-calling when supported by the engine."
CTEMPLATE = 
[
  syst(
    "Answer the user's question using the provided tools when helpful.\n",
    "If a tool is needed, call it with valid arguments.\n",
    "If no tool is needed, answer directly.\n",
    "Available tools:\n",
    "%<boxcar_descriptions>s\n",
    "%<next_actions>s"
  ),
  hist,
  user("%<input>s")
].freeze

Constants inherited from Boxcar

Boxcar::SCHEMA_KEY_ALIASES, Boxcar::TYPE_ALIASES

Instance Attribute Summary collapse

Attributes inherited from Train

#boxcars, #early_stopping_method, #engine_prefix, #final_answer_prefix, #max_iterations, #name_to_boxcar_map, #observation_prefix, #question_prefix, #return_intermediate_steps, #return_values, #thought_prefix, #using_xml

Attributes inherited from EngineBoxcar

#engine, #prompt, #stop, #top_k

Attributes inherited from Boxcar

#description, #name, #parameters, #return_direct

Instance Method Summary collapse

Methods inherited from Train

#boxcar_descriptions, #boxcar_names, #construct_scratchpad, #extract_boxcar_and_input, #finish_boxcar_name, #get_boxcar_result, #get_next_action, #init_prefixes, #input_keys, #key_and_value_text, #next_actions, #observation_text, #output_keys, #plan, #pre_return, #prepare_for_new_call, #return_stopped_response, #should_continue?

Methods inherited from EngineBoxcar

#apply, #extract_code, #generate, #input_keys, #output_key, #output_keys, #predict, #prediction_variables

Methods inherited from Boxcar

#apply, assi, #conduct, #conduct_result, hist, #input_keys, #output_keys, #parameters_json_schema, #run, #run_result, #schema, syst, #tool_call_name, #tool_definition, #tool_spec, user, #validate_inputs, #validate_outputs

Constructor Details

#initialize(boxcars:, engine: nil, name: DEFAULT_NAME, description: DEFAULT_DESCRIPTION, prompt: nil, **kwargs) ⇒ ToolTrain

Returns a new instance of ToolTrain.



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# File 'lib/boxcars/train/tool_train.rb', line 53

def initialize(boxcars:, engine: nil, name: DEFAULT_NAME, description: DEFAULT_DESCRIPTION, prompt: nil, **kwargs)
  @wants_next_actions = kwargs.fetch(:wants_next_actions, false)
  prompt ||= my_prompt
  super(boxcars:, engine:, prompt:, name:, description:, **kwargs)
end

Instance Attribute Details

#wants_next_actions ⇒ Object

Returns the value of attribute wants_next_actions.



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# File 'lib/boxcars/train/tool_train.rb', line 8

def wants_next_actions
  @wants_next_actions
end

Instance Method Details

#call(inputs:) ⇒ Object

Tool-calling runtime loop; does not use text parsing.



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# File 'lib/boxcars/train/tool_train.rb', line 64

def call(inputs:)
  prepare_for_new_call
  ensure_tool_calling_engine!

  conversation_messages = initial_messages(inputs)
  tool_specs = boxcars.map(&:tool_spec)
  intermediate_steps = []
  iterations = 0
  responses_state = responses_runtime? ? { previous_response_id: nil, response_input: nil } : nil

  while should_continue?(iterations)
    response = normalize_response_payload(tool_call_response(conversation_messages, tool_specs, responses_state:))
    assistant_message = extract_assistant_message(response)
    conversation_messages << assistant_message

    tool_calls = assistant_message[:tool_calls]
    if tool_calls.is_a?(Array) && !tool_calls.empty?
      response_tool_outputs = []
      tool_calls.each do |tool_call|
        action, observation, tool_message, return_direct = execute_tool_call(tool_call)
        intermediate_steps << [action, observation]
        Boxcars.debug "Observation: #{observation}", :green

        return pre_return(TrainFinish.new({ return_values[0] => observation }, log: ""), intermediate_steps) if return_direct

        conversation_messages << tool_message
        response_tool_outputs << responses_tool_output_item(tool_call, observation) if responses_state
      end

      if responses_state
        responses_state[:previous_response_id] = response[:id]
        responses_state[:response_input] = response_tool_outputs
      end

      iterations += 1
      next
    end

    responses_state[:response_input] = nil if responses_state

    final_text = extract_assistant_text(assistant_message)
    output = TrainFinish.new({ output: final_text }, log: final_text)
    return pre_return(output, intermediate_steps)
  end

  pre_return(TrainFinish.new({ output: "Agent stopped due to max iterations." }, log: ""), intermediate_steps)
end

#prediction_additional(_inputs) ⇒ Object 



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# File 'lib/boxcars/train/tool_train.rb', line 59

def prediction_additional(_inputs)
  { boxcar_descriptions:, next_actions: }.merge(super)
end