{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://openwop.dev/spec/v1/workload-identity.schema.json",
  "title": "OpenWOP workload identity and delegated actor chain (RFC 0154)",
  "description": "RFC 0154 §A/§B. An authenticated workload identity, and the delegation context a request may carry.\n\nThe governing rule is negative and it is why every object here is closed: raw certificates, tokens, proofs, and credentials MUST NOT enter these objects. `subject` is an OPAQUE identifier and `proofRef` is a REFERENCE. A verified identity is a fact about a completed verification, not a container for the material that proved it — and these objects are projected into events, spans, and audit records, which is exactly where credential material must never reach (`SECURITY/threat-model-secret-leakage.md`).\n\nThe second rule is that identity is not authorization (RFC 0147 R12). Knowing which workload called says nothing about what it may do; tenant, audience, and policy are re-evaluated at every boundary.",
  "type": "object",
  "additionalProperties": false,
  "required": ["scheme", "subject"],
  "properties": {
    "scheme": {
      "enum": ["spiffe", "mtls-san", "cloud-subject", "oauth-client"],
      "description": "How the identity was presented and verified. Closed: an unrecognized scheme is a verification path nobody implemented."
    },
    "subject": {
      "type": "string",
      "minLength": 1,
      "description": "Opaque verified identifier, e.g. a SPIFFE ID. MUST NOT be a credential, token, or certificate."
    },
    "issuer": { "type": "string", "minLength": 1 },
    "audience": {
      "type": "string",
      "minLength": 1,
      "description": "RFC 0154 §A — the audience the presented identity was minted for. A host MUST reject an identity whose audience is not its own: accepting one is how a credential valid elsewhere becomes a credential valid here."
    },
    "keyBinding": {
      "type": "object",
      "additionalProperties": false,
      "description": "Proof-of-possession binding. Carries the METHOD and a thumbprint reference, never the key.",
      "required": ["method"],
      "properties": {
        "method": { "enum": ["mtls", "dpop"] },
        "thumbprintRef": {
          "type": "string",
          "pattern": "^sha256:[0-9a-f]{64}$",
          "description": "Digest reference to the bound key. Pattern-constrained so a raw key cannot be pasted here and still validate."
        }
      }
    },
    "delegation": {
      "type": "object",
      "additionalProperties": false,
      "description": "RFC 0154 §B — the verified delegation chain, if any.",
      "required": ["chain", "audience"],
      "properties": {
        "chain": {
          "type": "array",
          "minItems": 1,
          "description": "Ordered delegation hops. Non-empty: a delegation context with no chain claims a delegation nobody can inspect.",
          "items": {
            "type": "object",
            "additionalProperties": false,
            "required": ["subject"],
            "properties": {
              "subject": { "type": "string", "minLength": 1 },
              "issuer": { "type": "string", "minLength": 1 },
              "scopes": {
                "type": "array",
                "uniqueItems": true,
                "items": { "type": "string", "minLength": 1 },
                "description": "RFC 0154 §B — the effective scopes VERIFIED for this hop from its proof (RFC 0049 scope grammar). OPTIONAL and provenance, not authorization: the host still evaluates the resolved principal's own scopes. When present on consecutive hops, a later hop's scopes MUST NOT exceed the previous hop's (`auth.md` §\"Bounds\" — scope amplification is refused: `delegation_scope_amplified`)."
              }
            }
          }
        },
        "audience": { "type": "string", "minLength": 1 },
        "expiresAt": {
          "type": "string",
          "format": "date-time",
          "description": "RFC 0154 §B — a delegation without an expiry is a standing grant, which is not what delegation means."
        },
        "proofRef": {
          "type": "string",
          "pattern": "^sha256:[0-9a-f]{64}$",
          "description": "Digest REFERENCE to the verified proof. Never the proof itself."
        }
      }
    }
  }
}