Engine at a glance

Engine is an experimental, local-first runtime for durable goals across software and physical worlds. It combines a durable Heart, exactly one active and replaceable general executive brain, zero or more specialist brains, and installable world plugins.

A request can be immediate—“turn this light off”—or become a durable intent: ACHIEVE an outcome once, or MAINTAIN it as the world changes. Engine persists that intent independently of the conversation, model, or process that first expressed it.

interaction  ->  intelligence  ->  Engine  ->  target / world
chat or API      model/planner     durable     software, home,
                                  runtime      business, energy,
                                               or machine

The intelligence layer is replaceable cognition, not operational authority. The design starts with a current world and a desired world that continue to exist without a model context:

durable current world + durable desired goal
                |
                v
     event or poll wakes the Heart
                |
                v
         observe again and assess
                |
                v
      brain/specialist proposes
                |
                v
 schema -> policy -> authorization
                |
                v
       execute -> observe again
                |
                v
      oracle -> receipt -> experience

A brain may choose and propose. The Heart maintains the cycle, state, and causal history. Policy grants or denies authority. A target-specific executor acts. An event is only a wake-up hint, and an API acknowledgement is only an execution fact. Only a fresh observation and an effect oracle may establish what actually happened within their current coverage.

The essence in four statements

Heart means continuity. Goals, snapshots, receipts, and experience remain durable outside the model session.
Brain means replaceable cognition, not authority. A deterministic planner or model-backed executive chooses the next cognitive step; specialists provide bounded advice.
Plugins represent worlds with their own semantics. Providers observe; controllers translate; executors act; oracles measure effects.
Success requires independent evidence. Model output or an API acknowledgement is never enough.

What to expect today

Status	Meaning in this documentation
Implemented	Present in the current action lifecycle and v3 plugin contracts
Fake/simulation-tested	Proved automatically, but not evidence of physical safety
Live read-only	Observed against a real target without mutation
Roadmap	A direction or hypothesis, not a feature available today

The current repository contains:

engine-heart, with the Heart, durable world store, policy, learning, and routines;
engine-sdk, with engine.plugin/v3, v2 compatibility, scaffolding, and conformance tooling;
engine-runtime, with the composition root, discovery, lease, and the engine CLI;
a warehouse reference plugin, context plugin, Homey plugin, and opt-in bounded ntfy lifecycle observer;
tests for reconstruction, stale/denied/malformed cases, immediate and task lifecycles, and bounded learning.

The current evidence boundary is deliberately narrower than the vision: Homey observation is Live read-only, while its v2 mutation path is Fake/simulation-tested. STREAM, multiple general executive brains, trained mini-brains, and physical-safety certification have not been demonstrated. The end goal works through five possible applications and labels each one at this boundary.

Choose a reading path

I want to understand Engine

I want to understand every capability and boundary

I want to build

I want to position Engine

The fixed checksum

LLM proposal != authority
prediction != observation
policy != physical safety
deliberation != realtime control
simulation evidence != real-world certification
generic lifecycle != generic device semantics
state != weights
imagine != execute

These statements are not slogans added after the fact. They define which code, tests, and claims belong in Engine.

The essence in four statements​

What to expect today​

Choose a reading path​

I want to understand Engine​

I want to understand every capability and boundary​

I want to build​

I want to position Engine​

The fixed checksum​