WorldSeed is an axiomatic specification and executable infrastructure for physically learnable worlds. It defines world identity, state ontology, actions, observers, sensing boundaries, numerical semantics, and irreversible degradation as explicit, verifiable research entities. A minimal set of normative axioms (S1–S19) prevents implicit semantic assumptions. This record includes the WorldSeed paper, reference specifications, and a compliance checker (WorldSeed-Lint) that mechanically verifies whether declared world representations satisfy the axioms. WorldSeed is intended as foundational research infrastructure and does not evaluate learning algorithms or benchmarks.