# Implementation Plan: Pipeline Pause/Resume (pipeline_pause_resume_20260306)

> **Reference:** [Spec](./spec.md) | [Architecture Guide](../../../docs/guide_architecture.md)

## Phase 1: Pause Mechanism
Focus: Add pause event to ConductorEngine

- [x] Task 1.1: Initialize MMA Environment
- [x] Task 1.2: Add pause event to ConductorEngine (0c3a206)
    - WHERE: `src/multi_agent_conductor.py` `ConductorEngine.__init__`
    - WHAT: Threading event for pause control
    - HOW:
      ```python
      self._pause_event: threading.Event = threading.Event()
      ```

- [x] Task 1.3: Check pause in run loop (0c3a206)
    - WHERE: `src/multi_agent_conductor.py` `run()`
    - WHAT: Wait while paused
    - HOW:
      ```python
      while True:
       if self._pause_event.is_set():
        time.sleep(0.5)
        continue
       # Normal processing...
      ```

## Phase 2: Pause/Resume Methods
Focus: Add control methods

- [x] Task 2.1: Add pause method (0c3a206)
    - WHERE: `src/multi_agent_conductor.py`
    - HOW: `self._pause_event.set()`

- [x] Task 2.2: Add resume method (0c3a206)
    - WHERE: `src/multi_agent_conductor.py`
    - HOW: `self._pause_event.clear()`

## Phase 3: UI Controls
Focus: Add pause/resume buttons

- [x] Task 3.1: Add pause/resume button (3cb7d4f)
    - WHERE: `src/gui_2.py` MMA dashboard
    - WHAT: Toggle button for pause state
    - HOW:
      ```python
      is_paused = engine._pause_event.is_set()
      label = "Resume" if is_paused else "Pause"
      if imgui.button(label):
       if is_paused:
        engine.resume()
       else:
        engine.pause()
      ```

- [x] Task 3.2: Add visual indicator (3cb7d4f)
    - WHERE: `src/gui_2.py`
    - WHAT: Banner or color when paused
    - HOW:
      ```python
      if engine._pause_event.is_set():
       imgui.text_colored(vec4(255, 200, 100, 255), "PIPELINE PAUSED")
      ```

## Phase 4: Testing
- [x] Task 4.1: Write unit tests
- [x] Task 4.2: Conductor - Phase Verification
