Class: Google::ADK::LoopAgent

Inherits:
BaseAgent show all
Defined in:
lib/google/adk/agents/workflow_agents/loop_agent.rb

Overview

Agent that executes another agent in a loop

Constant Summary

Constants inherited from BaseAgent

BaseAgent::AGENT_NAME_REGEX

Instance Attribute Summary collapse

Attributes inherited from BaseAgent

#after_agent_callback, #before_agent_callback, #description, #name, #parent_agent, #sub_agents

Instance Method Summary collapse

Methods inherited from BaseAgent

#clone, #find_agent, #find_sub_agent, from_config, #run_live

Constructor Details

#initialize(name:, agent:, description: nil, loop_condition: nil, max_iterations: 10, before_agent_callback: nil, after_agent_callback: nil) ⇒ LoopAgent

Initialize a loop agent

Parameters:

  • name (String) —

    Agent name

  • description (String) (defaults to: nil) —

    Agent description (optional)

  • agent (BaseAgent) —

    Agent to execute in loop

  • loop_condition (Proc) (defaults to: nil) —

    Condition to continue loop (optional)

  • max_iterations (Integer) (defaults to: 10) —

    Maximum iterations (default: 10)

  • before_agent_callback (Proc) (defaults to: nil) —

    Callback before agent execution

  • after_agent_callback (Proc) (defaults to: nil) —

    Callback after agent execution



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# File 'lib/google/adk/agents/workflow_agents/loop_agent.rb', line 18

def initialize(name:, agent:, description: nil, loop_condition: nil,
               max_iterations: 10, before_agent_callback: nil,
               after_agent_callback: nil)
  super(
    name: name,
    description: description || "Executes #{agent.name} in a loop",
    sub_agents: [agent],
    before_agent_callback: before_agent_callback,
    after_agent_callback: after_agent_callback
  )

  @agent = agent
  @loop_condition = loop_condition
  @max_iterations = max_iterations
end

Instance Attribute Details

#agent ⇒ Object (readonly)

Returns the value of attribute agent.



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# File 'lib/google/adk/agents/workflow_agents/loop_agent.rb', line 7

def agent
  @agent
end

#loop_condition ⇒ Object (readonly)

Returns the value of attribute loop_condition.



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# File 'lib/google/adk/agents/workflow_agents/loop_agent.rb', line 7

def loop_condition
  @loop_condition
end

#max_iterations ⇒ Object (readonly)

Returns the value of attribute max_iterations.



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# File 'lib/google/adk/agents/workflow_agents/loop_agent.rb', line 7

def max_iterations
  @max_iterations
end

Instance Method Details

#run_async(message, context: nil) {|Event| ... } ⇒ Object

Run agent in a loop

Parameters:

  • message (String) —

    Initial message

  • context (InvocationContext) (defaults to: nil) —

    Invocation context

Yields:

  • (Event) —

    Events during execution



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# File 'lib/google/adk/agents/workflow_agents/loop_agent.rb', line 39

def run_async(message, context: nil)
  Enumerator.new do |yielder|
    invocation_id = context&.invocation_id || "loop-#{SecureRandom.uuid}"

    # Yield start event
    start_event = Event.new(
      invocation_id: invocation_id,
      author: @name,
      content: "Starting loop execution with agent #{@agent.name}"
    )
    yielder << start_event

    current_input = message
    iteration = 0
    last_result = nil

    # Loop while condition is met or until max iterations
    while iteration < @max_iterations
      # Check loop condition if provided
      if @loop_condition && !@loop_condition.call(last_result, iteration)
        break
      end

      # Yield iteration event
      iteration_event = Event.new(
        invocation_id: invocation_id,
        author: @name,
        content: "Iteration #{iteration + 1}/#{@max_iterations}"
      )
      yielder << iteration_event

      begin
        # Run the agent
        agent_output = nil
        if @agent.respond_to?(:run_async)
          @agent.run_async(current_input, context: context).each do |event|
            yielder << event
            # Capture last content as result
            agent_output = event.content if event.content
          end
        else
          error_event = Event.new(
            invocation_id: invocation_id,
            author: @name,
            content: "Agent #{@agent.name} does not implement run_async"
          )
          yielder << error_event
        end

        # Update for next iteration
        last_result = agent_output || current_input
        current_input = last_result
        iteration += 1

      rescue StandardError => e
        # Handle errors
        error_event = Event.new(
          invocation_id: invocation_id,
          author: @name,
          content: "Error in iteration #{iteration + 1}: #{e.message}"
        )
        yielder << error_event
        iteration += 1
      end
    end

    # Yield completion event
    end_event = Event.new(
      invocation_id: invocation_id,
      author: @name,
      content: "Completed loop execution after #{iteration} iterations. Final result: #{last_result}"
    )
    yielder << end_event
  end
end