Helpers and types

Builder creation and extension

Export	Purpose
`defineSchema(type, schema, defaults?)`	Creates a strict callable builder from a Zod schema.
`withAdditionalProperties(entity, properties)`	Adds explicitly chosen properties after validation. Cannot replace `@type` or `@id`.
`withAdditionalTypes(entity, types)`	Adds one or more secondary Schema.org types while retaining the primary type.
`SchemaBuilder`	Callable builder interface with `.schema`, `.entityType`, and `.safeParse()`.
`SchemaInput`, `SchemaOutput`	Infers builder input and output from a Zod schema.

Graph composition

Export	Purpose
`buildJsonLdGraph(items, options?)`	Flattens, resolves, deduplicates, and wraps entities.
`resolveId(id, baseUrl?)`	Resolves a relative identifier against a canonical URL.
`resolveEntityIds(value, baseUrl?)`	Recursively resolves `@id`, `item`, and `url` values in a copied structure.
`GraphOptions`	`graph`, `context`, and `baseUrl` options.

Validation

Export	Purpose
`validateSchema(schema, data, options?)`	Parses with `throw`, `warn`, or `silent` failure handling.
`safeValidateSchema(schema, data, options?)`	Returns a discriminated success/error result.
`formatZodError(error, entityType?, data?)`	Produces the terminal-friendly diagnostic string.
`normalizeZodIssues(error, entityType?, data?)`	Produces stable structured issue details.
`SchemaValidationError`	Error with `code`, `entityType`, raw `issues`, normalized `details`, and formatted message.

Dates and durations

Export	Purpose
`formatIsoDuration(input)`	Converts duration shorthand to ISO 8601.
`parseDurationToMs(input)`	Converts a supported duration to milliseconds.
`parseDate(input, referenceDate?)`	Returns a `Date` or `null`, including relative expressions.
`formatIsoDate(input)`	Returns normalized ISO date/time output or throws.
`addDuration(date, duration)`	Adds a duration and returns an ISO string.
`diffDuration(start, end)`	Returns the difference as an ISO duration.
`IsoDateSchema`, `IsoDurationSchema`	Reusable transforming Zod schemas.
`DurationInput`, `DurationObject`	Public duration input types.

Serialization

Export	Purpose
`serializeJsonLd(data, options?)`	JSON-serializes and escapes unsafe HTML characters.
`escapeJsonLd(json)`	Escapes `<`, `>`, and `&` in an existing JSON string.
`SerializeOptions`	`pretty` and `indent` settings.

References and shorthands

Export	Purpose
`isIdReference(value)`	Detects fragment, path, HTTP(S), and URN reference strings.
`createEntityRef(schema, fallbackType?)`	Creates a Zod union for embedded entities and string/object references.
`createSearchAction(options)`	Creates a SearchAction and EntryPoint for a URL template.
`SpeakableSchema`	Validates and transforms CSS selectors or XPath into SpeakableSpecification.

Content helpers

Import these from either the package root or @unschema-graph/astro/content:

Export	Purpose
`toArticle`, `toBlogPosting`, `toNewsArticle`	Map an Astro content entry to a validated article entity.
`extractImage`	Converts strings or Astro image metadata into an image value.
`extractKeywords`	Converts arrays or comma-separated strings into keyword arrays.
`extractWordCount`	Computes a simple word count from source content.
`ContentEntryLike`, `ArticleMappingOptions`	Public mapping types.

Programmatic audit

Import getHtmlFiles, auditHtmlContent, auditHtmlDirectory, AuditError, and AuditResult from @unschema-graph/core/audit. This entry point uses Node.js filesystem modules and should only run in build tooling or server code.