# `Diffo.Provider.Extension.Verifiers.VerifyParties`
[🔗](https://github.com/diffo-dev/diffo/blob/v0.9.0/lib/diffo/provider/extension/verifiers/verify_parties.ex#L5)

Verifies party declarations and roles — no duplicates, party_type modules must exist and extend BaseParty

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