Glossary

The whole system is a handful of nouns. (These terms also get hover-definitions wherever they appear in the docs.)

Backend

Pluggable storage behind the LedgerBackend protocol — in-memory, SQLite, JSON files, Snowflake, or a remote HTTP service. Swapping it never changes your code.

Composite

A governed group whose members are themselves models — a business-level entity (e.g. a "Credit Decision System") that rolls up its scorecard, rules, and ETL. See Composites.

Connector

A source that emits DataNodes from a platform (SQL, REST, GitHub, …) via the SourceConnector protocol. See Connectors & discovery.

DataNode

The core graph primitive: anything with typed input/output ports — an ML model, a heuristic rule, an ETL job, an alert queue. See DataNode & the graph.

DataPort

A named connection point on a DataNode, optionally carrying schema so identically named outputs from different models don't falsely link.

Dependency graph

The links between nodes, built automatically when an output port name matches an input port name (connect()).

Event log

The inventory itself — an append-only sequence of immutable Snapshots. Nothing is overwritten, so history is always reconstructable.

ModelRef

A model's stable identity: name, owner, type, risk tier, purpose, status. The minimum a regulator needs. See Snapshots & the event log.

Point-in-time

Reconstruction of the inventory as it stood on any past date, via inventory_at().

Profile

A pluggable compliance check (sr_11_7, eu_ai_act, nist_ai_rmf) that validates a model's completeness against a framework. See Governance.

Snapshot

An immutable, content-addressed record of one thing that happened to a model — a registration, a retrain, a validation. The unit of the event log.

Tag

A mutable named pointer to a specific Snapshot (e.g. production, latest-validated).