# Embedding Space Identity

## Consumer enforcement

ExampleRAG stores `embedding_space_id` on the ModelForge profile, collection identity and every new
shadow payload. The adapter rejects a vector response whose space differs even when dimensions are
equal. The current production index is recorded as `legacy-observed` until complete upstream
revision provenance exists.

An EmbeddingSpace identifies the vector geometry produced by an exact ArtifactSet,
RuntimeProfile fingerprint and CapabilityContract. Dimension and normalization are facts, not the
identity: two 1024-dimensional deployments can still be incompatible spaces.

The identity digest is immutable and the M5 production space is
`326075d3-c75f-402e-b1b4-4d243c6a9ca2`. Every change is classified `requires_reindex`; existing
vectors must never be silently reused under another identity.

M13 freezes the target `EmbeddingSpace` and source space reference in its immutable plan. A reindex
plan must name a separate shadow target; changing deployment, runtime, preprocessing, dimension,
normalization, query/document semantics or distance identity requires a new plan and validation.