Concepts at a glance
One sentence on each of the eight nouns the rest of the docs assume you’ve met.
Spine
The small typed core at the centre of everything: entities, database, event log.
Entity
A named noun from your domain vocabulary — Project, Timeline, Asset. Five to fifteen of them is the working range.
Operation
Any typed function that touches the spine. Operations come in two flavours, below.
Query
An operation that reads. Pure, side-effect-free, replayable, cacheable, safe for any surface.
Command
An operation that writes. Mutates state and appends a typed row to the event log in the same transaction. Knows its inverse, or is explicitly marked irreversible.
Event log
Append-only, typed history of every command ever attempted. Joins together what the system does with what the system is.
Workflow
A named composition of operations — a script, a skill, a notebook — that runs the same way from any surface and produces the same log entries.
Surface
Anything that calls operations. Codex desktop, Claude Code, Cowork, your own web UI, a CLI, an overnight pipeline, a test harness. Interchangeable, because they all speak the same operations.