Data model

The data model blocks: what each one is for, how to choose between neighbours, and a live starter example you can edit — converted at build time from the authoring skill your agent reads. Every example body is YAML; in a real doc the fence language is the block type (for example sequence … ). Schemas are strict — unknown fields are rejected. The full field contract for any block — every field, enum, and terse one-line form, generated from the schema — is npx chiltepin block <type>. See the block catalog for every block rendered on one page.

Shape: Network — entities joined by cardinality edges, no nesting (erd). Answers: What shape is the data at rest, and how do the entities relate? Not this family: data in motion → dfd (flows.md) or sankey (charts-overviews.md); classes with behavior → uml (architecture.md); example rows the reader should scan → table (tables-data.md).

Data model

erd — entities and relations

Entity cards with columns and key markers, joined by crow's-foot edges. The renderer centres the aggregate root (the "one" side of most relations), fans neighbours out by relation depth, and never truncates a card. Answers: what shape is the data at rest, and how do the entities relate? Write columns and relations in the terse forms. Use fromCol / toCol only when the FK cannot be inferred from ref or the column name. schema on an entity, or groups, draws a panel around the entities that share it. Budget: 20 entities or 60 columns per block; chiltepin check warns past that. Split the model by domain. erd, not uml, for data at rest; uml for classes with behaviour; dfd for data in motion.

Other ways to write it

A ```dbml or ```prisma fence, or a ```mermaid fence with erDiagram, parses into an erd. chiltepin sync sql schema.sql --out docs/data-model.md (or sync dbml / sync prisma) converts a schema file. The dialect subsets are in reference/mermaid.md (Input dialects).