Class: Kward::Agent

Inherits:
Object
  • Object
show all
Defined in:
lib/kward/agent.rb

Overview

Runs model turns, handles context compaction, dispatches tool calls, and streams high-level events back to CLI and RPC callers.

Agent is the main turn orchestrator. It should know what a turn means: append the user's input, call the model, persist assistant/tool messages, retry once after recoverable context overflow, apply in-flight steering, and emit frontend-neutral Events::* objects. It should not know terminal or RPC rendering details; callers translate events into their own UI protocol.

Tool implementations own local side effects. Client owns provider HTTP details. Conversation owns transcript state. Keep future changes in the lowest layer that owns the behavior, and use Agent only for cross-step turn coordination.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(client:, tool_registry: ToolRegistry.new, conversation: Conversation.new, telemetry_logger: TelemetryLogger.new) ⇒ Agent

Returns a new instance of Agent.



27
28
29
30
31
32
 
# File 'lib/kward/agent.rb', line 27

def initialize(client:, tool_registry: ToolRegistry.new, conversation: Conversation.new, telemetry_logger: TelemetryLogger.new)
  @client = client
  @tool_registry = tool_registry
  @conversation = conversation
  @telemetry_logger = telemetry_logger
end

Instance Attribute Details

#conversation ⇒ Object (readonly)

Returns the value of attribute conversation.



34
35
36
 
# File 'lib/kward/agent.rb', line 34

def conversation
  @conversation
end

Instance Method Details

#ask(input, display_input: nil, on_reasoning_delta: nil, on_retry: nil, cancellation: nil, steering: nil) {|event| ... } ⇒ String

Adds a user message, compacts context when needed, and runs the turn.

Parameters:

  • input (String) —

    text sent to the model

  • display_input (String, nil) (defaults to: nil) —

    alternate text kept for transcripts

Yield Parameters:

  • event (Object) —

    streamed turn event for frontends

Returns:

  • (String) —

    final assistant answer



42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
 
# File 'lib/kward/agent.rb', line 42

def ask(input, display_input: nil, on_reasoning_delta: nil, on_retry: nil, cancellation: nil, steering: nil, &block)
  started_at = @telemetry_logger.monotonic_now
  status = "completed"
  error = nil
  cancellation&.raise_if_cancelled!
  @conversation.refresh_system_message_if_workspace_agents_changed!
  @conversation.append_user(input, display_content: display_input)
  auto_compact_if_needed
  run_turn(on_reasoning_delta: on_reasoning_delta, on_retry: on_retry, cancellation: cancellation, steering: steering, &block)
rescue StandardError => e
  status = "failed"
  error = e
  raise e
ensure
  log_turn(duration_ms: @telemetry_logger.duration_ms(started_at), status: status, error: error)
end

#run_turn(on_reasoning_delta: nil, on_retry: nil, cancellation: nil, steering: nil) {|event| ... } ⇒ String

Runs model calls until the assistant returns an answer without pending tool calls, including tool dispatch and one context-overflow retry.

Yield Parameters:

  • event (Object) —

    streamed turn event for frontends

Returns:

  • (String) —

    final assistant answer



64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
 
# File 'lib/kward/agent.rb', line 64

def run_turn(on_reasoning_delta: nil, on_retry: nil, cancellation: nil, steering: nil)
  overflow_retried = false
  steering_state = build_steering_state(steering) do |event|
    yield event if block_given?
  end
  loop do
    cancellation&.raise_if_cancelled!
    begin
      message = chat(on_reasoning_delta: on_reasoning_delta, on_retry: on_retry, cancellation: cancellation, steering: steering) do |event|
        yield event if block_given?
      end
    rescue StandardError => e
      raise if cancellation&.cancelled?
      raise unless !overflow_retried && ContextOverflow.error?(e) && compact_after_context_overflow(e)

      overflow_retried = true
      next
    end
    update_conversation_runtime(message)
    yield Events::AssistantMessage.new(message: message) if block_given?
    @conversation.append_assistant(message)
    steered_after_message = append_steering_events(steering_state)
    yield Events::SteeringApplied.new(count: steered_after_message) if block_given? && steered_after_message.positive?

    tool_calls = message["tool_calls"] || message[:tool_calls] || []
    if tool_calls.empty?
      next if steered_after_message.positive?

      answer = safe_answer(message.fetch("content", message[:content] || ""))
      yield Events::Answer.new(content: answer) if block_given?
      return answer
    end

    tool_calls.each do |tool_call|
      cancellation&.raise_if_cancelled!
      yield Events::ToolCall.new(tool_call: tool_call) if block_given?
      tool_started_at = @telemetry_logger.monotonic_now
      content = nil
      status = "completed"
      error = nil
      begin
        content = @tool_registry.dispatch(tool_call, @conversation, cancellation: cancellation)
      rescue StandardError => e
        status = "failed"
        error = e
        raise e
      ensure
        log_tool(tool_call, content: content, duration_ms: @telemetry_logger.duration_ms(tool_started_at), status: status, error: error)
      end
      cancellation&.raise_if_cancelled!
      yield Events::ToolResult.new(tool_call: tool_call, content: content) if block_given?
    end
    steered_after_tools = append_steering_events(steering_state)
    yield Events::SteeringApplied.new(count: steered_after_tools) if block_given? && steered_after_tools.positive?
  end
ensure
  steering_state&.fetch(:unsubscribe)&.call
end