Implement Phase 1 - Core Multi-Agent System (MAS) Infrastructure

Feature: Implement Phase 1 - Core Multi-Agent System (MAS) Infrastructure

This pull request introduces the foundational components of the Multi-Agent System (MAS) framework, establishing a robust and modular core for future development.

Key Components Implemented/Updated:

• BaseAgent (src/core/base_agent.py):

  • Defines the abstract base for all agents, including unique identification, registration with central services, standardized message handling, and core lifecycle management (initialization, running, idle, busy, shutdown).
  • Integrates helpers for TaskTracker interaction.

• MessageRouter (src/core/message_router.py):

  • Serves as the central communication hub, now fully refactored to delegate message publishing and retrieval to a concrete ICommunicationBackend implementation. This ensures clear separation of concerns and extensibility for various communication transports.

• AgentRegistry (src/core/agent_registry.py):

  • Provides centralized agent registration, unregistration, and discovery services, along with basic role tracking.

• Protocols (src/core/protocols.py):

  • Introduces core enums (MessageType, AgentState, AgentCapability, AgentRole, TaskStatus) for standardization across the framework.
  • Defines the ICommunicationBackend interface, enforcing a contract for communication backend implementations.

• Exceptions (src/core/exceptions.py):

  • Introduces a hierarchy of custom exceptions (MASFrameworkException, AgentRegistrationError, MessageHandlingError, TaskManagementError) to provide more granular and specific error handling within the framework.

• TaskTracker (src/core/task_tracker.py):

  • A new centralized service for managing the lifecycle of tasks within the MAS, supporting creation, status updates (PENDING, IN_PROGRESS, COMPLETED, FAILED), assignment, and retrieval.
  • Designed with thread-safety using threading.Lock to handle concurrent agent access.

• InMemoryBackend (src/communication/inmemory_backend.py):

  • A concrete implementation of ICommunicationBackend utilizing Python's in-memory queues, serving as the default communication transport for development and single-process deployments.

How Components Integrate:

• Agents & Core Services: BaseAgent instances are initialized with references to the MessageRouter, AgentRegistry, and TaskTracker, allowing them to interact with these central services.
• Communication Abstraction: MessageRouter's dependency on ICommunicationBackend ensures it can seamlessly switch between InMemoryBackend (current) and future external backends (e.g., Redis, RabbitMQ) without changes to the core routing logic.
• Task Lifecycle: SenderAgent creates tasks via TaskTracker and includes task IDs in messages. ReceiverAgent extracts these IDs and updates task statuses (e.g., IN_PROGRESS to COMPLETED) in the TaskTracker, demonstrating a basic cooperative workflow.
• Standardization & Error Handling: Protocols are utilized across components for consistent type definitions, and Exceptions are integrated for robust error propagation and handling.

Documentation & Examples:

• docs/architecture.md: This file has been updated to include a comprehensive overview of the MAS framework's layered architecture, detailing each core component and their interactions. It also includes a visual system architecture diagram.
• examples/simple_mas.py: The example script has been updated to demonstrate the full integration of these Phase 1 components. It showcases agents registering, sending/receiving messages, creating/updating tasks, and gracefully shutting down.

This phase lays a solid, extensible, and well-structured foundation for the development of more complex multi-agent behaviors and capabilities.