# Execution Monitors -- Technical Specification

**Version**: v1.0.0 | **Status**: Active | **Last Updated**: March 2026

## Overview

Placeholder submodule reserved for execution progress monitoring within the orchestrator. Currently contains no implementation beyond the package marker.

## Architecture

Designed as a future extension point for real-time workflow execution monitoring. When implemented, monitors would observe task state transitions, track progress percentages, estimate remaining time, and emit progress events for UI consumption.

## Current State

- `__init__.py` exports an empty `__all__` list.
- No concrete monitor classes or functions are implemented.

## Planned Interface

When monitors are added, they should follow this contract:

| Class / Function | Description |
|-----------------|-------------|
| `ProgressMonitor` | Tracks task completion counts against total and estimates time remaining |
| `ResourceMonitor` | Monitors CPU, memory, and thread pool utilization during workflow execution |
| `HealthMonitor` | Detects stalled or hung tasks based on configurable heartbeat timeouts |

## Dependencies

- **Internal**: `orchestrator.engines` (WorkflowResult, TaskState), `orchestrator.observability` (event emission)
- **External**: None currently

## Constraints

- Monitors must be non-blocking; observation must not slow task execution.
- Progress updates should be debounced to avoid flooding event buses.
- Zero-mock: real metrics collection only, `NotImplementedError` for unimplemented paths.

## Error Handling

- Unimplemented monitor methods must raise `NotImplementedError`.
- All errors logged before propagation.

## Navigation

- **Self**: `SPEC.md`
- **Parent**: [../README.md](../README.md)
- **Readme**: [README.md](README.md)
- **Agents**: [AGENTS.md](AGENTS.md)
- **Repository Root**: [README.md](../../../../README.md)
