Planner

Planner = Stage<PlanningInput, PlannerCandidate>

Defined in: packages/engine/src/lib/planner/stage.ts:127

A complete plan for one chart_request: a stage from the Engine’s input to a candidate it can validate. Only these two ends are fixed; the types between stages belong to whoever composes them with pipeline.

One planner serves every session and concurrent request of an Engine, so any state it keeps across calls must be keyed by the request (or session) and safe under concurrent calls. State from one request must never affect another; a per-request cache belongs in a WeakMap keyed by input.request, for example.