RXON (Reverse Axon) Protocol

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RXON (Reverse Axon) is a lightweight reverse-connection inter-service communication protocol designed for the HLN (Hierarchical Logic Network) architecture.

It serves as the "nervous system" for distributed multi-agent systems, connecting autonomous nodes (Holons) into a single hierarchical network.

🧬 The Biological Metaphor

The name RXON is derived from the biological term Axon (the nerve fiber). In classic networks, commands typically flow "top-down" (Push model). In RXON, the connection initiative always comes from the subordinate node (Worker/Shell) to the superior node (Orchestrator/Ghost). This is a "Reverse Axon" that grows from the bottom up, creating a channel through which commands subsequently descend.

✨ Key Features

• Pluggable Transports: Full abstraction from the network layer. The same code can run over HTTP, WebSocket, gRPC, or Tor.
• Generic Event System: Unified signaling mechanism for progress updates, custom alerts, and real-time metrics.
• Zero Trust Identity Chain: Built-in support for hierarchical event bubbling with origin_worker_id and bubbling_chain to prevent spoofing in multi-layer holarchies.
• Universal Resource Telemetry: Heartbeats include granular usage metrics for CPU, RAM, and any hardware devices (GPU, TPU, Sensors, Robots) via extensible properties and metrics.
• Task Prioritization & Deadlines: Built-in support for task priority and execution deadline (timestamp) to enable smart local scheduling and auto-cancellation of stale tasks.
• Zero Dependency Core: The protocol core has no external dependencies (standard transports use aiohttp and orjson).
• Strictly Typed Contracts: All messages (tasks, results, heartbeats) define their data structures via JSON Schemas, enabling automated validation and smart dispatching.
• Blob Storage Native: Built-in support for offloading heavy data via S3-compatible storage (rxon.blob).

🏗 Architecture

The protocol is divided into two main interfaces:

1. Transport (Worker side): Interface for initiating connections, retrieving tasks, emitting events, and sending results.
2. Listener (Orchestrator side): Interface for accepting incoming connections and routing messages to the orchestration engine.

High-Signal Telemetry (Heartbeats)

RXON Heartbeats provide the Orchestrator with a detailed view of the Holon's health:

• ResourcesUsage: Real-time CPU and RAM consumption.
• DeviceUsage: Per-device load and custom metrics (e.g., temperature, memory, battery level) for any hardware.
• hot_cache: List of artifacts/models currently loaded in memory.
• hot_skills: Detailed info about skills currently ready for immediate execution.

Skill Contracts

Every skill declared in RXON can now include:

• input_schema: JSON Schema for parameters.
• output_schema: JSON Schema for results.
• events_schema: Mapping of event names to their JSON Schemas.
• output_statuses: List of valid logic outcomes (e.g., success, retry_later).

🛡️ Error Handling

RXON uses a dedicated exception hierarchy grounded in RxonError. It also defines standardized error codes for task results:

• CONTRACT_VIOLATION_ERROR: The worker's output does not match its declared schema.
• DEPENDENCY_MISSING_ERROR: A required dependency (artifact, file, service) is missing.
• RESOURCE_EXHAUSTED_ERROR: Physical resources (RAM, VRAM, CPU) are exhausted.
• LIMIT_EXCEEDED_ERROR: Logical limits (Quotas, Rate limits, Context windows) exceeded.
• TIMEOUT_ERROR: The worker could not finish in time (or the deadline has passed).
• LATE_RESULT: (Response) The orchestrator refused the result because the deadline has passed.

🧪 Testing

The library includes a MockTransport to simplify testing Workers in isolation without running a real Orchestrator.

from rxon.testing import MockTransport

# Use standard factory with mock:// scheme
transport = create_transport("mock://", "test-worker", "token")
await transport.connect()

# Inject tasks directly
transport.push_task(my_task_payload)

📜 License

The project is distributed under the Mozilla Public License 2.0 (MPL 2.0).

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Mantra: "The RXON is the medium for the Ghost."