ShEx 2.1 defines shapes and node constraints for describing RDF graph structure

The ShEx 2.1 final Community Group Report defines how Shape Expressions describe RDF nodes and graphs. Node constraints cover IRI, blank node, or literal forms; shapes describe triples with predicates, cardinalities, and datatypes. The abstract states shapes can communicate data structures, generate or validate data, or drive UIs. It is not a W3C Standard on the Standards Track.

For knowledge-graph and data-contract teams, ShEx is an alternative or complement to SHACL when the job is to publish an expected graph pattern as a reusable artifact. IMPORTS and language-tag value sets in 2.1 address modular schemas and multilingual literals.

Governed shared meaning needs an explicit shape of instance data, not only class hierarchies. ShEx’s framing—structures tied to processes and interfaces—aligns with treating semantic models as contracts agents and content systems can validate against.

Editors listed are Eric Prud'hommeaux, Iovka Boneva, Jose Emilio Labra Gayo, and Gregg Kellogg; a primer and test suite are referenced for non-normative learning and conformance.