# KYA-OS Protocol Schemas

> The canonical registry of JSON Schemas for the KYA-OS protocol. Every schema is versioned and served at a stable $id URL with open CORS.

The canonical registry for the KYA-OS protocol's JSON Schemas. Every schema is versioned and immutable, served at a stable $id URL with open CORS. Reference one to validate KYA-OS messages, or to resolve $ref pointers from any JSON Schema validator.

## Schemas

- [KYA-OS Audit Record](https://schema.kya-os.org/v1/protocol/audit/record/v1.0.0): Versioned, portable audit log record summarizing a single verified KYA-OS tool call. Provides a standard, cross-implementation format for compliance and non-repudiation trails (audit.v1).
- [KYA-OS Needs-Authorization Error](https://schema.kya-os.org/v1/protocol/authorization/needs-authorization/v1.0.0): Error returned when a tool call requires user authorization. The response is itself signed (detached JWS in _meta) so the client can verify the authorizationUrl before trusting it; the client resumes the flow with resumeToken after the user grants authority (SPEC §9.2).
- [KYA-OS Delegation Credential](https://schema.kya-os.org/v1/protocol/delegation/credential/v1.0.0): W3C Verifiable Credential containing a KYA-OS delegation with CRISP constraints.
- [KYA-OS StatusList2021 Credential](https://schema.kya-os.org/v1/protocol/delegation/status-list/v1.0.0): W3C StatusList2021 Verifiable Credential used to publish delegation revocation or suspension state. The interoperable wire format for revocation when delegator and verifier are operationally decoupled (KYA-OS L3).
- [KYA-OS Handshake Request](https://schema.kya-os.org/v1/protocol/handshake/request/v1.0.0): Client-initiated handshake request to establish a KYA-OS session with nonce-based replay protection.
- [KYA-OS Handshake Response](https://schema.kya-os.org/v1/protocol/handshake/response/v1.0.0): Server response to a successful handshake request, establishing session context.
- [KYA-OS Detached Proof](https://schema.kya-os.org/v1/protocol/proof/detached/v1.0.0): Cryptographic proof binding an MCP tool request/response pair to an agent's identity and session context.
- [KYA-OS Discovery Document](https://schema.kya-os.org/v1/protocol/well-known/v1.0.0): Well-known discovery document served at /.well-known/mcp for KYA-OS service discovery.

## Reference

- [KYA-OS specification](https://kya-os.org/mcp)
- [schema-index.json](https://schema.kya-os.org/schema-index.json)
- [Donated core repository](https://github.com/decentralized-identity/kya-os-mcp)

Last updated: 2026-06-10