Module types 

Schema-as-artifact type format.

Serde-based, YAML-authorable type definitions.

Structs

DueAxis

A type’s declared due axis (first-author-path plan 08): which of its fields carry deadline semantics, so the engine’s due-brief (memstead due) can render “what is due next” without knowing any domain vocabulary. Validated at schema load: date_field must be a date-typed metadata field of the type, status_field an enum-typed one, every open_values entry a member of that enum, and lead_section (optional — rendered as “what must happen first”) a declared section key. The axis is rendering-only: it never enforces anything (constraints own enforcement) and the engine never advances a date (the agent loop is the runtime).

Exemplar

One canonical exemplar entity for a type — a complete entity in the mem markdown shape: title, metadata overrides, section bodies, and relationship entries with placeholder targets. Engine-validated at schema install/seal through the real create path, so it can never teach a shape the validator would refuse.

ExemplarRelation

One relationship entry on an Exemplar.

MetadataFieldDef

A metadata (frontmatter) field.

MustReach

One reachability obligation on a type definition. The obligated entity must reach at least one non-stub entity whose type is in terminal_types, walking edges whose rel-type is in relationships (an inline relation set), in direction, within max_depth hops when bounded. Evaluated on the health sweep only (constraints axis), never on the write path — no single write completes a transitive absence. The incoming direction with max_depth: 1 covers the required-incoming-edge case.

RequiredOutgoing

One outgoing-edge requirement block on a type definition. Lists one or more relationship names and a cardinality constraint they must jointly satisfy. The schema author groups multiple alternative relationships into a single block when “any of these” satisfies the rule (e.g. [CHOSEN, REJECTED] together with at_least_one would require at least one outgoing edge across both names — but the planning schema lists each as its own block instead, so each block gets its own warning entry).

SectionDef

A section within an entity (e.g. “Claim”, “Evidence”).

SignalDef

One declared aggregate signal on a type definition. This wave ships one kind, edge_load: count the edges of a named rel-type set, in a named direction, on entities of this type, optionally restricted to edges whose counterpart entity holds a named enum value. Thresholds map counts to levels; below the first threshold the served level is none. Values are computed at read time in O(degree), never stored, never part of _hash; a signal may not reference another signal, and nothing multiplies, averages, or decays — a count and a threshold are the whole vocabulary.

SignalThreshold

One threshold step of a signal declaration.

TableFormat

The table contract of a format-declared section: columns pins header names and order; column_patterns maps column name → regex per cell (implicitly anchored). Column-count enforcement is ours by decision — GFM silently pads/truncates short or long rows, so a row with the wrong cell count is our refusal, not the parser’s.

TypeDefinition

Enums

ConstraintDef

One declared keep-health constraint on a type — the constraint vocabulary (agent-toolbox plan 07). Declarations travel sealed with the schema package and are rendered on the memstead_schema response at BOTH verbosity levels (a hidden legality condition is a defect class of its own). The kind tag is closed: an unknown kind fails deserialization, so no declaration can load and be silently ignored. Forms land vertically — a form is only declarable once the engine evaluates it.

ConstraintSeverity

Uniform severity for the constraint vocabulary — one model across every constraint form, never five ad-hoc ones. warn produces a health finding only; block additionally refuses at write time (and still surfaces pre-existing violations in health). Severity applies to every write surface uniformly — operator-mode bypasses allowlists, never validation.

FieldType

Filterable

PropagationDirection

Traversal direction for ConstraintDef::StatusPropagation.

ReachDirection

Walk direction for MustReach — wire literals out / in, matching the store’s relationship rendering and memstead_search’s direction parameter.

RequiredCardinality

Required-cardinality variants. AtLeastOne is the only variant shipped initially; ExactlyOne is the obvious next variant but is not yet wired.

Serialization

SignalKind

Closed signal-kind vocabulary. Adding a member is a format-generation event.

SignalLevel

Signal levels — deliberately NOT ConstraintSeverity: a signal level is the output of a threshold, not the severity of a violation. warn participates in health --strict like a warn-tier constraint finding; notice never does — that is the whole difference between the two.

Functions

derive_section_key

Derive the storage key a ## Heading line resolves to.