Known limitations

• The 51 builders intentionally model a strict subset of Schema.org, not the complete vocabulary.
• withAdditionalProperties() permits controlled extensions after validation; it cannot prove an extension is meaningful or eligible for a search feature.
• The audit checks JSON syntax and graph structure in built HTML. It does not crawl URLs, validate every Schema.org semantic rule, or guarantee rich results.
• Relative identities require a correct baseUrl; Core and Svelte do not infer an origin from framework configuration.
• Content helpers recognize documented conventional field names. Custom CMS models require explicit overrides or mappings.
• Relative date expressions depend on the current clock unless a reference date is supplied.
• The Node audit entry point is not browser-safe.
• The project is pre-1.0; documented interfaces can still evolve with release notes.

These constraints are product boundaries, not hidden failures. See troubleshooting for diagnosis and migrations before upgrading.