Target
A named operation (build, test, ...) you invoke with magus run <target>; it may compose a spell's tool-native operations and depend on other targets. Target in full.
Op
A single tool-native command a target composes (long form: operation); the middle of the work hierarchy (Spell to Op to Target). Op in full.
Cache
The content-addressed store magus consults before running a target, so unchanged work is skipped. Cache in full.
Output reference
A short, shareable id such as out1a2b3c for one target execution's captured output; magus query output prints those exact bytes. In OpenTelemetry terms it names a span. Output reference in full.
Trace
OpenTelemetry's name for one whole magus invocation; every target it runs is a span beneath it. Trace in full.
Span
OpenTelemetry's name for one unit of work under a trace: a target execution, whose sub-operations are child spans. An output reference points at a span's captured output. Span in full.
Knowledge graph
The queryable graph of a workspace's spells, targets, docs, and code relationships; query it with magus query/explain/path. Knowledge graph in full.
Invocation
One magus process's recorded facts (the targets it finished, their outcomes, the lease it acted as, and the session it ran in when a host delivered one), kept in a repo-scoped store every worktree shares. magus session lists them; the store prunes itself by last-fact age. Invocation in full.
Run
One target executing under one magus invocation, such as magus run test web or magus affected ci. A run keeps its captured output behind an output reference. Every magus run is a run whether or not any job asked for it; see Job for how the two relate. Run in full.