Class: Clacky::MessageHistory

Inherits:
Object
  • Object
show all
Defined in:
lib/clacky/message_history.rb

Overview

MessageHistory wraps the conversation message list and exposes business-meaningful operations instead of raw array manipulation.

Internal fields (task_id, created_at, system_injected, etc.) are kept in the internal store but stripped when calling #to_api.

Constant Summary collapse

INTERNAL_FIELDS =

Fields that are internal to the agent and must not be sent to the API.

%i[
  task_id created_at system_injected session_context memory_update
  subagent_instructions subagent_result subagent_transcript token_usage
  compressed_summary chunk_path truncated transient
  chunk_index chunk_count ext_events
].freeze
MAX_EXT_EVENTS_PER_MESSAGE =

Cap on persisted ext_events per message. These are milestone events (progress chatter is transient), so a handful per message is the norm — the cap only exists to stop a runaway extension. Oldest are dropped first.

50
MAX_EXT_EVENT_BYTES =

Oversized payloads belong in a file, not in session.json (which is rewritten in full on every save).

8 * 1024

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(messages = []) ⇒ MessageHistory

Returns a new instance of MessageHistory.



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# File 'lib/clacky/message_history.rb', line 29

def initialize(messages = [])
  @messages = messages.dup
end

Class Method Details

.pad_reasoning_content_if_needed(msgs, force: false) ⇒ Object

Public helper: pad assistant messages that lack a reasoning_content field with an empty string, either when forced or when the payload already shows evidence of thinking-mode (at least one assistant message with reasoning_content).

Exposed as a class method so Time Machine's active_messages path can reuse the exact same logic without routing through #to_api.



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# File 'lib/clacky/message_history.rb', line 436

def self.pad_reasoning_content_if_needed(msgs, force: false)
  should_pad = force || msgs.any? { |m| m[:role] == "assistant" && m[:reasoning_content] }
  return msgs unless should_pad

  msgs.map do |m|
    next m unless m[:role] == "assistant"
    next m if m.key?(:reasoning_content)

    m.merge(reasoning_content: "")
  end
end

Instance Method Details

#append(message) ⇒ Object

Append a single message hash to the history.

When appending a user message, automatically drop any trailing assistant message that has unanswered tool_calls (no tool_result follows it). This prevents API error 2013 ("tool call result does not follow tool call") when a previous task ended before observe() could append tool results (e.g. subagent crash, interrupt, or error).



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# File 'lib/clacky/message_history.rb', line 44

def append(message)
  if message[:role] == "user"
    drop_dangling_tool_calls!
  end
  @messages << deep_sanitize_utf8(message)
  self
end

#append_ext_event(event) ⇒ Object

Append a custom extension event onto the most recent message so it is persisted with the session and can be replayed after a reload. Events are anchored to the last message: on replay they are re-emitted right after that message, preserving chronological order. No-op when the history is still empty (nothing to anchor to).



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# File 'lib/clacky/message_history.rb', line 104

def append_ext_event(event)
  msg = @messages.last
  return self unless msg

  if JSON.generate(event).bytesize > MAX_EXT_EVENT_BYTES
    Clacky::Logger.warn("ext event #{event[:type].inspect} dropped: payload exceeds #{MAX_EXT_EVENT_BYTES} bytes")
    return self
  end

  list = (msg[:ext_events] ||= [])
  list.shift while list.size >= MAX_EXT_EVENTS_PER_MESSAGE
  list << deep_sanitize_utf8(event)
  self
end

#attach_to_tool_result(tool_call_id, key, value) ⇒ Object

Attach a key/value onto the most recent tool result message matching the given tool_call_id. Handles both OpenAI-style (role:"tool", tool_call_id) and Anthropic-style (role:"user" with tool_result blocks) messages. No-op if no matching message is found.



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# File 'lib/clacky/message_history.rb', line 89

def attach_to_tool_result(tool_call_id, key, value)
  msg = @messages.reverse.find do |m|
    (m[:role] == "tool" && m[:tool_call_id] == tool_call_id) ||
      (m[:role] == "user" && m[:content].is_a?(Array) &&
        m[:content].any? { |b| b.is_a?(Hash) && b[:type] == "tool_result" && b[:tool_use_id] == tool_call_id })
  end
  msg[key] = value if msg
  self
end

#delete_where(&block) ⇒ Object

Remove all messages matching the block in-place. Generic history pruning utility — used by callers that need to strip transient/system-injected messages out of the persisted history (e.g. compaction, rollback on 400 errors).



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# File 'lib/clacky/message_history.rb', line 80

def delete_where(&block)
  @messages.reject!(&block)
  self
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/clacky/message_history.rb', line 215

def empty?
  @messages.empty?
end

#estimate_tokens ⇒ Object

Estimate total token count for all messages. Uses the ~4 chars/token heuristic (works well for English/code). Handles string content, array content blocks, and tool_calls.



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# File 'lib/clacky/message_history.rb', line 222

def estimate_tokens
  @messages.sum { |m| estimate_message_tokens(m) }
end

#has_system_prompt? ⇒ Boolean

True when a system prompt message is present in the history. Used by inject_session_context to avoid injecting context messages before the system prompt has been built (which would cause the guard in run() to skip building it altogether).

Returns:

  • (Boolean) 


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# File 'lib/clacky/message_history.rb', line 161

def has_system_prompt?
  @messages.any? { |m| m[:role] == "system" }
end

#last_injected_chunk_count ⇒ Object

Return the chunk_count from the most recently injected chunk index message. Used by inject_chunk_index_if_needed to avoid re-injecting when nothing changed.



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# File 'lib/clacky/message_history.rb', line 186

def last_injected_chunk_count
  msg = @messages.reverse.find { |m| m[:chunk_index] }
  msg&.dig(:chunk_count) || 0
end

#last_real_user_index ⇒ Object

Return the index of the last real (non-system-injected) user message. Used by restore_session to trim back to a clean state on error.



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# File 'lib/clacky/message_history.rb', line 198

def last_real_user_index
  @messages.rindex { |m| m[:role] == "user" && !m[:system_injected] }
end

#last_session_context_date ⇒ Object

Return the session_date value from the most recent session_context message. Used by inject_session_context_if_needed to avoid re-injecting on the same date.



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# File 'lib/clacky/message_history.rb', line 179

def last_session_context_date
  msg = @messages.reverse.find { |m| m[:session_context] }
  msg&.dig(:session_date)
end

#mutate_last_matching(predicate, &block) ⇒ Object

Mutate the last message matching the predicate lambda in-place. Used by execute_skill_with_subagent to update instruction messages.



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# File 'lib/clacky/message_history.rb', line 121

def mutate_last_matching(predicate, &block)
  msg = @messages.reverse.find { |m| predicate.call(m) }
  block.call(msg) if msg
  self
end

#pending_tool_calls? ⇒ Boolean

True when the last assistant message has tool_calls but no tool_result has been appended yet (would cause a 400 from the API).

Returns:

  • (Boolean) 


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# File 'lib/clacky/message_history.rb', line 167

def pending_tool_calls?
  return false if @messages.empty?

  last = @messages.last
  return false unless last[:role] == "assistant" && last[:tool_calls]&.any?

  last_assistant_idx = @messages.rindex { |m| m == last }
  @messages[(last_assistant_idx + 1)..].none? { |m| m[:role] == "tool" || m[:tool_results] }
end

#pop_last ⇒ Object

Remove and return the last message.



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# File 'lib/clacky/message_history.rb', line 72

def pop_last
  @messages.pop
end

#real_user_messages ⇒ Object

Return only real (non-system-injected) user messages.



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# File 'lib/clacky/message_history.rb', line 192

def real_user_messages
  @messages.select { |m| m[:role] == "user" && !m[:system_injected] }
end

#replace_all(new_messages) ⇒ Object

Replace the entire message list (used by compression rebuild).



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# File 'lib/clacky/message_history.rb', line 66

def replace_all(new_messages)
  @messages = new_messages.map { |m| deep_sanitize_utf8(m) }
  self
end

#replace_system_prompt(content, **extra) ⇒ Object

Replace (or insert at head) the system prompt message. Used by session_serializer#refresh_system_prompt.



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# File 'lib/clacky/message_history.rb', line 54

def replace_system_prompt(content, **extra)
  msg = { role: "system", content: content }.merge(extra)
  idx = @messages.index { |m| m[:role] == "system" }
  if idx
    @messages[idx] = msg
  else
    @messages.unshift(msg)
  end
  self
end

#rollback_before(message) ⇒ Object

Roll back the history to just before the given message object. Removes the message and anything appended after it. Used to undo a failed speculative append (e.g. compression message that errored).



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# File 'lib/clacky/message_history.rb', line 145

def rollback_before(message)
  idx = @messages.index { |m| m.equal?(message) }
  return self unless idx

  @messages = @messages[0...idx]
  self
end

#size ⇒ Object

───────────────────────────────────────────── Size helpers ─────────────────────────────────────────────



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# File 'lib/clacky/message_history.rb', line 211

def size
  @messages.size
end

#subagent_instruction_message ⇒ Object

Return the message with :subagent_instructions set.



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# File 'lib/clacky/message_history.rb', line 203

def subagent_instruction_message
  @messages.find { |m| m[:subagent_instructions] }
end

#to_a ⇒ Object

Return a shallow copy of the message list, excluding transient messages. Transient messages (e.g. brand skill instructions) are valid during the current session but must not be persisted to session.json. For serialization, compression, and cloning.



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# File 'lib/clacky/message_history.rb', line 263

def to_a
  @messages.reject { |m| m[:transient] }.dup
end

#to_api(force_reasoning_content_pad: false, task_chain: nil) ⇒ Object

Return a clean copy of messages suitable for sending to the LLM API:

  • strips internal-only fields
  • pads reasoning_content on synthetic assistant messages when the conversation is running against a thinking-mode provider

Convert to API-ready messages. When task_chain is given (a Set of task IDs forming the active task's ancestor chain), messages tagged with a task_id outside that chain are dropped first — this is the Time Machine path, ensuring undone/sibling-branch turns never reach the LLM. Messages without a task_id (system / injected context) are always kept.

Parameters:

  • force_reasoning_content_pad (Boolean) (defaults to: false) —

    When true, unconditionally pad every assistant message that lacks a reasoning_content field with an empty string. This is set by the LLM caller AFTER a 400 "reasoning_content must be passed back" error as a one-shot retry signal — the history-evidence heuristic below can't fire when the previous turns came from a provider that keeps thinking inline (e.g. MiniMax: ... in content), so this bypass lets us recover on the retry without a server restart.



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# File 'lib/clacky/message_history.rb', line 248

def to_api(force_reasoning_content_pad: false, task_chain: nil)
  source = if task_chain
    @messages.select { |m| !m[:task_id] || task_chain.include?(m[:task_id]) }
  else
    @messages
  end
  msgs = source.map { |m| strip_for_api(m) }
  msgs = repair_tool_call_pairing(msgs)
  ensure_reasoning_content_consistency(msgs, force: force_reasoning_content_pad)
end

#truncate_from(index) ⇒ Object

Remove all messages from index onward (used by restore_session on error).



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# File 'lib/clacky/message_history.rb', line 128

def truncate_from(index)
  @messages = @messages[0...index]
  self
end

#truncate_from_created_at(created_at) ⇒ Object

Truncate history starting from the user message with the given created_at timestamp. Removes that message and everything after it. Returns self.



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# File 'lib/clacky/message_history.rb', line 135

def truncate_from_created_at(created_at)
  idx = @messages.index { |m| m[:role] == "user" && m[:created_at].to_s == created_at.to_s }
  return self unless idx

  truncate_from(idx)
end