Scenario

A first-class axis on every posting naming which version of the future or past a record belongs to. The engine knows four kinds — actual, planned, simulated and custom — and Plan, Budget and Forecast are presets of planned, never kinds of their own. A scenario is stored either as a full independent set of postings or as adjustment-only deltas over a base.

Canonical definition from the Ledgerbook glossary. Definitions are the product vocabulary — the same terms the API and MCP tools use.