Functions describe themselves through metadata — stability, examples, parameter info, ordering and
null semantics — which DuckDB reads for introspection and the query optimizer. The protocol and
invocation types model the request/response lifecycle on the wire. See the
Metadata guide for authoring metadata via nested Meta classes.
::: vgi.metadata
::: vgi.invocation
::: vgi.protocol.CatalogAttachRequest.client_capabilities options: heading_level: 3
::: vgi.protocol