{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://timelordraps.github.io/verifier/schemas/vstd-typed-formation-0.1.schema.json",
  "title": "Verifier Standard experimental typed-formation subject and certificate",
  "$comment": "An integer identifier (ID) selects a node; the ID tag constructs an identity path.",
  "description": "Structural schema only for Verifier Standard (VSTD). Canonical bytes, backward references, exact context and proof bindings, formation types, endpoints, resource budgets and observation preservation require the mechanism. This schema establishes no source-ground derivation, self-status, completeness or authority axiom agency.",
  "oneOf": [
    {
      "$ref": "#/$defs/subject"
    },
    {
      "$ref": "#/$defs/certificate"
    }
  ],
  "$defs": {
    "digest": {
      "type": "string",
      "pattern": "^sha256:[0-9a-f]{64}$",
      "minLength": 71,
      "maxLength": 71
    },
    "index": {
      "type": "integer",
      "minimum": 0,
      "maximum": 1023
    },
    "node": {
      "oneOf": [
        {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "tag",
            "payload_digest"
          ],
          "properties": {
            "tag": {
              "const": "ATOM"
            },
            "payload_digest": {
              "$ref": "#/$defs/digest"
            }
          }
        },
        {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "tag",
            "argument"
          ],
          "properties": {
            "tag": {
              "const": "APPLY"
            },
            "argument": {
              "$ref": "#/$defs/index"
            }
          }
        },
        {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "tag",
            "at"
          ],
          "properties": {
            "tag": {
              "const": "ID"
            },
            "at": {
              "$ref": "#/$defs/index"
            }
          }
        },
        {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "tag",
            "source",
            "target"
          ],
          "properties": {
            "tag": {
              "const": "APPLY_STEP"
            },
            "source": {
              "$ref": "#/$defs/index"
            },
            "target": {
              "$ref": "#/$defs/index"
            }
          }
        },
        {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "tag",
            "left",
            "right"
          ],
          "properties": {
            "tag": {
              "const": "COMPOSE"
            },
            "left": {
              "$ref": "#/$defs/index"
            },
            "right": {
              "$ref": "#/$defs/index"
            }
          }
        },
        {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "tag",
            "value"
          ],
          "properties": {
            "tag": {
              "const": "QUOTE"
            },
            "value": {
              "$ref": "#/$defs/index"
            }
          }
        },
        {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "tag",
            "code"
          ],
          "properties": {
            "tag": {
              "const": "READ"
            },
            "code": {
              "$ref": "#/$defs/index"
            }
          }
        }
      ]
    },
    "subject": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "schema_version",
        "profile_digest",
        "context",
        "nodes",
        "root"
      ],
      "properties": {
        "schema_version": {
          "const": "VSTD-TYPED-FORMATION-0.1"
        },
        "profile_digest": {
          "$ref": "#/$defs/digest"
        },
        "context": {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "ground_artifact_digest",
            "authority_axiom_agency_digest"
          ],
          "properties": {
            "ground_artifact_digest": {
              "$ref": "#/$defs/digest"
            },
            "authority_axiom_agency_digest": {
              "$ref": "#/$defs/digest"
            }
          }
        },
        "nodes": {
          "type": "array",
          "minItems": 1,
          "maxItems": 1024,
          "items": {
            "$ref": "#/$defs/node"
          }
        },
        "root": {
          "$ref": "#/$defs/index"
        }
      }
    },
    "certificate": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "schema_version",
        "subject_digest",
        "profile_digest",
        "steps",
        "root"
      ],
      "properties": {
        "schema_version": {
          "const": "VSTD-TYPED-FORMATION-CERTIFICATE-0.1"
        },
        "subject_digest": {
          "$ref": "#/$defs/digest"
        },
        "profile_digest": {
          "$ref": "#/$defs/digest"
        },
        "steps": {
          "type": "array",
          "minItems": 1,
          "maxItems": 1024,
          "items": {
            "type": "object",
            "additionalProperties": false,
            "required": [
              "node",
              "rule",
              "premises"
            ],
            "properties": {
              "node": {
                "$ref": "#/$defs/index"
              },
              "rule": {
                "enum": [
                  "ATOM",
                  "APPLY",
                  "ID",
                  "APPLY_STEP",
                  "COMPOSE",
                  "QUOTE",
                  "READ"
                ]
              },
              "premises": {
                "type": "array",
                "maxItems": 2,
                "items": {
                  "$ref": "#/$defs/index"
                }
              }
            }
          }
        },
        "root": {
          "$ref": "#/$defs/index"
        }
      }
    }
  }
}