Glossary

The normative definitions are in spec/v0.1/index.md, and defined terms are capitalized wherever they appear.

Term	Definition
Hub	The one process that owns every Device, its Driver, the Safety Kernel, the confirmation queue and the audit log
Client	A program that connects to a Hub and sends requests
Device	One piece of hardware, or one set of entities in a bridged system, described by one Device File
Device File	A YAML document ending in .hal.yaml that describes one Device, its channels, actions, limits, safe state and provenance
Driver	Code that communicates with Devices over one protocol and changes hardware only when it consumes a Grant
Safety Kernel	The deterministic part of a Hub that evaluates every command and issues Grants for the ones that pass
Grant	A single-use permission for exactly one operation, bound to one Device, one target and one value, with an expiry
Principal	The identity behind a request, of kind human, agent, routine or system, with a scope
Conformance Level	core, control or full, naming what a Hub implements or a Driver supports
Confirmation Request	A command the Hub holds in its queue until a human Principal approves or rejects the command
Risk Level	low, medium or high, set for each channel and action from what it is. It decides whether a human confirms the limits first