# `AshNeo4j.Verifiers.VerifyIdentities`
[🔗](https://github.com/diffo-dev/ash_neo4j/blob/v0.10.1/lib/verifiers/verify_identities.ex#L5)

Refuses, at compile time, any `identity` that can't be enforced as a Neo4j
uniqueness constraint (#20) — so an unenforceable identity is caught loudly here
rather than silently leaving a gap that permits duplicate/split records.

Neo4j's `REQUIRE … IS UNIQUE` can't express two identity options:

  * `nils_distinct?: false` — Neo4j treats `nil`s as distinct and can't be made
    to treat them as equal.
  * a **filtered** identity (`where:`) — there is no partial/filtered constraint.

The runtime counterpart is `AshNeo4j.Error.UnsupportedIdentity`, returned by
`AshNeo4j.Constraint` for the same cases.

---

*Consult [api-reference.md](api-reference.md) for complete listing*