# Requirements

- [Legal & Regulatory Layer](/interop/requirements/legal-and-regulatory-layer.md)
- [Governance and Policies Layer](/interop/requirements/governance-and-policies-layer.md)
- [Audit and Compliance sub-layer](/interop/requirements/governance-and-policies-layer/audit-and-compliance-sub-layer.md)
- [Operations sub-layer](/interop/requirements/governance-and-policies-layer/operations-sub-layer.md)
- [Application Layer](/interop/requirements/application-layer.md)
- [Integration and Middleware Layer](/interop/requirements/integration-and-middleware-layer.md)
- [Oracle sub-layer](/interop/requirements/integration-and-middleware-layer/oracle-sub-layer.md)
- [Semantic Layer](/interop/requirements/semantic-layer.md)
- [Syntactic Layer](/interop/requirements/syntactic-layer.md)
- [Foundational Layer](/interop/requirements/foundational-layer.md)
- [Discovery sub-layer](/interop/requirements/foundational-layer/discovery-sub-layer.md)
- [Smart contract sub-layer](/interop/requirements/foundational-layer/smart-contract-sub-layer.md)
- [Function call sub-layer](/interop/requirements/foundational-layer/function-call-sub-layer.md)
- [Messaging sub-layer](/interop/requirements/foundational-layer/messaging-sub-layer.md)
- [Transaction sub-layer](/interop/requirements/foundational-layer/transaction-sub-layer.md)
- [Consensus sub-layer](/interop/requirements/foundational-layer/consensus-sub-layer.md)
- [Data transfer sub-layer](/interop/requirements/foundational-layer/data-transfer-sub-layer.md)
- [Security sub-layer](/interop/requirements/foundational-layer/security-sub-layer.md)
- [Identity and Authentication](/interop/requirements/foundational-layer/security-sub-layer/identity-and-authentication.md)
- [Data Privacy](/interop/requirements/foundational-layer/security-sub-layer/data-privacy.md)
- [-](/interop/requirements/undefined.md)