Glossary

Terms used across the Manifold course. Runtime vocabulary aligns with the Phase 7 constructive-realization contract. For Pico-side vocabulary (Rule, Parser, Composer, Pico), see the Pico course glossary. For composition vocabulary (XRD, Composition, XR, Managed Resource), see the Crossplane course glossary.

Channel

A named runtime pathway that carries typed values between Elements inside an InteractionTopology. In this course, one Wrangler-declared Channel wires exactly one event into the hosted Pico. The Channel is the wire; it is not the payload.

Control Surface

An operator- or learner-facing interface that expresses OperatorIntent against declared runtime state. In this course the Control Surface is a small Python CLI-style shell command (kubectl exec / curl) that sends one event onto the Channel. Graphical Control Surfaces (for example, Home Assistant) are out of scope.

Event

A single value delivered onto a Channel. Under the Phase 7 contract an event conforms to an EventType — described here in prose and a small inline shape rather than a formal schema.

EventType

The typed contract for values carried by a Channel. In this course the only EventType is hello.request, a small JSON-shaped payload carrying a value field that the hosted Pico echoes back on its log.

InteractionTopology

A declarative description of which Elements interact through which Channels within a RuntimeEnvironment. In this course the topology is minimal: one Pico and one Channel, authored as a small Wrangler-style YAML fragment shipped with the lab.

Manifold

The RuntimeEnvironment taught in this course. Manifold hosts Pico Elements on a Kubernetes RuntimeSubstrate and owns their lifecycle and notification path. Manifold does not replace Kubernetes, Crossplane, or Sandcastle — it sits on top of them.

Observation

A runtime-captured fact about an Element’s behaviour inside a RuntimeEnvironment. In this course the single Observation is the one log line the hosted Pico prints in response to the one event sent onto its Channel. Observations feed Phase 2 feedback[].

OperatorIntent

A declaration of desired runtime state expressed through a Control Surface. In this course the OperatorIntent is: “send one hello.request event to the hosted Pico via channel hello, and capture the response.”

Pico engine

The in-process host, inside Manifold, that actually runs a Pico Element. The Pico engine consumes events from a Channel and produces Observations. It is the runtime counterpart of the hello-world-pico artifact produced by the Hello Pico lab.

RuntimeEnvironment

A concrete environment hosted on the RuntimeSubstrate in which Pico Elements execute and interact. In this course the RuntimeEnvironment is Manifold, deployed onto a local minikube cluster. A RuntimeEnvironment runs on the RuntimeSubstrate; it does not replace it.

RuntimeSubstrate

The underlying execution layer that hosts every runtime Element in the academy. In this course, and across the Hello Pico roadmap, the RuntimeSubstrate is always Kubernetes (concretely, minikube).

Wrangler

The InteractionTopology authoring surface. Wrangler outputs a declarative topology (Channels, subscriptions, children) that Manifold applies over the runtime. Wrangler is not the runtime; it is an additional declarative input to the same Realization chain.