zu-core 0.5.0

Zu core: contracts, ports, registry, loop, event bus

zu-core

The small, stable core of Zu: the typed contracts, the six ports, the plugin registry, the interpreter loop, and the event bus. It depends only on the standard library and Pydantic — it physically cannot import a model SDK, a browser, or any concrete adapter. It should be readable in an afternoon.

What's inside

Module	Responsibility
contracts.py	TaskSpec, Result, and the frozen Event envelope (types namespaced harness.* / data.*).
ports.py	The six Protocol ports + the capability envelope (CAP_*, EGRESS_OPEN, declared_envelope).
registry.py	The one registry the loop reads (entry points, decorators, config).
loop.py	The interpreter loop: provider → tool → detectors → finalise → validators, with the escalation ladder and budgets.
bus.py	The event bus: append-before-notify, with isolated destinations.
events.py	The event taxonomy (the stable set of harness.* / data.* type constants).
sinks.py	The in-memory default EventSink.
eventstore.py / codec.py / projections.py	Shared filter contract, the encryption-at-rest seam, and rebuildable read-side views.

The six ports

ModelProvider, Tool, Detector, Validator, SandboxBackend, EventSink — each a runtime-checkable structural Protocol. A plugin implements the shape; it never subclasses a framework.

This package registers no plugins — it defines the contracts every other package plugs into.

Tests

uv run pytest packages/zu-core — deterministic, offline.