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Effero Technical Architecture Deep-Dive

Effero is an open-source, production-grade agent runtime designed for physical and digital agency. It provides unified orchestration across local computers, robotics hardware, and IoT devices.


1. Six-Layer Subsystem Architecture

The Effero runtime is structured into six strictly separated, modular layers:

┌────────────────────────────────────────────────────────┐
│                   Layer 6: Interfaces                  │
│       CLI (REPL / Chat) · FastAPI REST · WebSockets    │
└───────────────────────────┬────────────────────────────┘
                            │
┌───────────────────────────▼────────────────────────────┐
│                    Layer 5: Protocols                  │
│         MCP (Stdio) · Wyoming Voice · A2A Mesh         │
└───────────────────────────┬────────────────────────────┘
                            │
┌───────────────────────────▼────────────────────────────┐
│                 Layer 4: Agent Core Engine             │
│   Planner Loop · Memory (Working/Episodic/Semantic)    │
│            Model Router · Fleet Coordinator            │
└─────────────┬───────────────────────────┬──────────────┘
              │                           │
┌─────────────▼───────────────┐ ┌─────────▼──────────────┐
│  Layer 3: Safety & Defense  │ │   Layer 2: Perception  │
│ Rust Policy Kernel (TCP RPC)│ │ Audio (ASR/TTS/VAD)    │
│  Human-in-the-Loop Approval │ │ Vision (YOLO/ONNX VLA) │
│       Bounds Clamping       │ │ Sensors (Hardware/Sys) │
└─────────────┬───────────────┘ └─────────┬──────────────┘
              │                           │
┌─────────────▼───────────────────────────▼──────────────┐
│             Layer 1: Skills & Hardware Adapters        │
│  Computer Use (OS / Playwright) · Robotics Kinematics  │
│  Serial / Dynamixel / Modbus · ROS 2 CDR · MQTT/Matter │
└────────────────────────────────────────────────────────┘

2. Core Execution Engine: The Planner Loop

The central reasoning engine is implemented in effero.core.planner.Planner: - System Grounding: Injects a unified prompt anchoring the agent's digital and physical actions. - Dynamic Schema Synthesis: Generates OpenAI-compliant tool schemas at runtime directly from registered skills in SkillRegistry. - Iterative Reasoning Loop: Evaluates user input against the prioritized fallback chain in ModelRouter (supporting local Ollama, cloud OpenAI, Anthropic Claude, and Google Gemini). - Safety Interception: Before dispatching any tool call, the action is verified with the Rust Safety Kernel (effero-safety-kernel) and routed through ApprovalHandler if classified as ACT_WITH_APPROVAL. - Context Preservation: Execution observations are appended to WorkingMemory while session histories are persisted to append-only JSONL files via EpisodicMemory.


3. Tiered Memory Hierarchy

  1. Working Memory (effero.core.memory.working):
  2. In-memory sliding window message buffer.
  3. Retains system instructions while truncating older dialogue turns to preserve LLM token context limits.
  4. Episodic Memory (effero.core.memory.episodic):
  5. Disk-persisted append-only interaction log (sessions/session_<timestamp>.jsonl).
  6. Stores timestamps, roles, raw model responses, and tool call traces for replay and post-hoc auditing.
  7. Semantic Memory (effero.core.memory.semantic):
  8. Zero-dependency local TF-IDF vector recall engine with subword trigram hashing and cosine similarity.
  9. Provides instant semantic retrieval of long-term preferences, user habits, and device states without external vector databases.

4. Hardware Safety & Policy Guardrails

Effero incorporates defense-in-depth for physical safety: - Rust Safety Kernel (crates/effero-safety-kernel): A deterministic engine evaluating mathematical and boolean conditions (time.hour >= 23, distance < 1.0m, speed > limit) over high-throughput TCP RPC (127.0.0.1:9400). - Safety Classifications (effero.sdk.SafetyClass): - READ_ONLY: Passive telemetry and sensing. Autonomous execution allowed. - ACT_AUTONOMOUS: Idempotent, low-risk local actions (e.g. homing joints, stopping motors). - ACT_WITH_APPROVAL: High-risk or physical actions requiring operator authorization. - ACT_RESTRICTED: High-consequence actions strictly gated by safety policies. - OS Destructive Filter: Native Windows automation (desktop.py) intercepts dangerous hotkey combinations (e.g. Alt+F4, Ctrl+Alt+Del) and enforces cursor bounding limits.


5. Protocols & Distributed Fleet Coordination

  • MCP Protocol (effero.protocols.mcp_server): Standard Model Context Protocol implementation over stdio, exposing Effero skills as tools to external agents (Claude Desktop, IDE agents).
  • Wyoming Voice (effero.protocols.wyoming): Wire-compatible with Home Assistant voice satellites for local wake-word, binary PCM audio streaming, speech-to-text, and text-to-speech synthesis.
  • A2A Mesh Protocol (effero.protocols.a2a): Agent-to-Agent REST API for multi-agent capability discovery (AgentCard) and remote task delegation (TaskMessage).
  • Fleet Consensus (effero.core.fleet): Decentralized multi-node task bidding via sealed-bid commit-reveal auctions (SealedBidAuction) and lease renewals (TaskLease).