Cross-Chain Identity Contracts

The Cross-Chain Identity contracts manage identity registries and credential lifecycles for ACE. They depend on the Policy Management contracts — registries are owned and governed by a PolicyEngine. The source code and full documentation are available in the cross-chain-identity package of the chainlink-ace repository (Business Source License 1.1).

Core interfaces

Interface
Description
IIdentityRegistryMaps wallet addresses to Cross-Chain Identifiers (CCIDs). Supports registering and removing address-to-CCID mappings, and looking up the CCID for a given address or all addresses for a given CCID.
ICredentialRegistryManages the lifecycle of credentials linked to a CCID — registration, renewal, removal, and expiration checks. Each credential is identified by a credentialTypeId (a keccak256 hash of the credential type string).
ICredentialRequirementsDefines which credentials a policy requires, which registries to check, and how many validations must pass. Supports complex rules via credential sources, minimum validation thresholds, and inverted checks.
IIdentityValidatorValidates whether an account meets all configured credential requirements. Used by the CredentialRegistryIdentityValidatorPolicy to check identities during policy evaluation.
ICredentialValidatorValidates whether specific credentials exist and are valid for a given CCID. Provides both single-credential and batch validation functions.
ICredentialDataValidatorOptional interface for inspecting the contents of a credential's credentialData field. Enables granular, data-level checks beyond simple attestation (e.g., verifying a specific claim within the credential payload).
ITrustedIssuerRegistryManages the list of trusted credential issuers — addresses authorized to register and manage credentials in a credential registry.

Repository documentation

The cross-chain-identity docs folder contains detailed guides:

  • Concepts — CCID model, credential type IDs, privacy, and design rationale
  • API Guide — Deploy registries, configure validator policies, and authorize issuers
  • API Reference — Complete interface specifications with function signatures, events, and errors
  • Credential Flow — End-to-end lifecycle from issuance to validation
  • Security Considerations — Issuer trust, PII handling, CCID correlation, and non-reverting requirements

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