Glossary

The Samoza OS vocabulary — every term that means something specific.

If you encounter a word in the Samoza docs that’s italicised, code-styled, or just looks meaningful, this is where it’s pinned down.

ABI

The Guest ABI — the binary interface between WASM guest programs and the runtime. See the ABI overview.

AIR

Anglish Intermediate Representation. A typed, deterministic serialisation produced by the Anglish compiler before MEX assembly.

Capability

A named permission a space declares in its space.yaml. The runtime enforces capability declarations at the ABI boundary — a guest cannot call a function it didn’t declare it would use.

Cluster

A set of zhosts that share a control plane and route messages to each other. Identified by ZMESH_CLUSTER.

Control plane

zmesh-controlplane. The central registry for zhost membership and super-node election. One per cluster.

Degraded

A topology state. Some spaces have failed; recovery is in progress. Can transition back to running (recovered) or to failed (recovery couldn’t place all spaces).

DF (Deterministic Function)

An agent kind. Routes work via deterministic logic, not LLMs. See :FUNC in Anglish and the AGENTIC vs FUNC distinction.

AF (Agentic Function)

An agent kind. Routes work via an LLM-backed selector. See :AGENTIC in Anglish.

Edge node

A zhost that runs workloads but does not coordinate the cluster. Reports to a super node.

MEX

Mixed Experience archive. The portable, signed, self-contained file format that packages a Samoza application. See the MEX format.

Mesh

The peer-to-peer network connecting zhosts. Routes messages between spaces wherever they’re running. Implemented by zmesh.

Path

A declared connection between two spaces. Messages flow along paths; spaces without a path between them cannot send to each other.

Recognizer

A small program that watches a sensor stream and emits computed events when patterns match. See events.register_recognizer in the ABI.

Space

A typed, sandboxed unit of computation. Every space declares a type — :UI, :IO, :DATA, :CHAT, :CALL — that constrains what it can do. Non-UI spaces are WebAssembly programs.

Space type

The semantic category of a space. Determines which ABI modules it can use, where it runs (browser vs. WASM), and what the runtime validates.

SPG

Space–Path Graph. The directed graph of spaces and paths declared by a topology. The unit of scheduling, instantiation, and recovery.

Super node

A zhost that coordinates the cluster — collects heartbeats, makes placement decisions, runs failure recovery. There is at least one per cluster; large clusters may have several for resilience.

Topology

A named collection of spaces and paths. The unit of deployment. Submitted to zrms, scheduled across zhosts.

WASM (WebAssembly)

The execution format for non-UI spaces. Guest programs compile to WASM via TinyGo and run inside zrun.

zbase

The service registry. Tracks every running service across the cluster. Backed by PostgreSQL on the cloud node, in-memory on edges.

zdesk

The browser-side runtime that renders UI spaces. A zdesk terminal can host one or more UI surfaces and connects back to the cluster’s mesh.

zedge

The runtime that serves static UI assets (HTML/CSS/JS) packaged in a MEX. Lives next to zrun on each edge node.

zevents

The runtime for event recognizers. Watches sensor streams and emits computed events into the mesh.

zhost

A single physical or virtual host running the Samoza stack. Identified by ZMESH_ZHOST_ID.

zmesh

The peer-to-peer networking agent on each zhost. Handles connections, message routing, and space registration. There’s also zmesh-controlplane, the central registry.

zrms

The resource manager. Plans topology placement, collects heartbeats, runs failure recovery.

zrun

The WebAssembly execution engine. Loads guest WASM, provides the ABI, manages space lifecycle (on_init / on_process / on_close).

zshell

The operator’s command-line interface. Talks to all the services through one surface. See the zshell tour.