Introduction

Spatial Context Protocol — real-time AI execution runtime for one embodied system.

What is SCP

SCP gives one body to one LLM. The body runs at 60Hz, holds its own decision cache, and only calls the brain when the cache cannot answer. After a few sessions on the same task, the brain stops being called at all.

npm install scp-protocol

If you have several bodies to coordinate, install Plexa on top.

How it differs from MCP

	MCP	SCP
Who initiates	Brain asks, tool answers	Body acts, brain advises
Body	Passive (waits)	Active (60Hz tick loop)
Memory	None	Pattern store + adaptive memory
Cost over time	Constant	Drops as novelty decreases

What SCP adds to MCP

1. Body class with a tick loop. SCPBody runs at 60Hz, owns its sensors, owns its actuators. The brain is a slow advisor, not the driver.
2. Pattern store. Every brain decision is cached against a feature vector. Next time the same situation appears, the body answers locally in 0.1 ms.
3. Adaptive memory. When the cache misses but a similar situation has been seen, a similarity-scored layer answers without a brain call.

Quick start

const { SCPBody, PatternStore, AdaptiveMemory } = require("scp-protocol")
const { OllamaBridge } = require("scp-protocol/bridges/ollama")

class Patrol extends SCPBody {
  static bodyName = "patrol"
  static tools = {
    halt: { description: "stop", parameters: {} },
    advance: {
      description: "move forward",
      parameters: { speed: { type: "number", min: 0, max: 1, required: true } },
    },
  }
  async halt() { /* drive hardware */ }
  async advance({ speed }) { /* drive hardware */ }
}

const body = new Patrol({
  patternStore: new PatternStore({ featureExtractor: (e) => ({ kind: e.kind }) }),
  adaptiveMemory: new AdaptiveMemory({ threshold: 0.8 }),
  brain: new OllamaBridge({ model: "llama3.2" }),
})

That is the whole contract a body owner has to write. Sensor reading, brain calling, and outcome reporting happen inside the base class.

Examples

See /examples/cart-pole for a complete walkthrough that goes from npm install to a balanced inverted pendulum in under ten minutes.