{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "$id": "https://x402.nsgoods.org/preflight/schema/preflight_v3.schema.json",
 "title": "x402 preflight composite envelope (preflight_v3)",
 "description": "FROZEN after publication; supersedes preflight_v2 at an announced version boundary (2026-09-01). Identical to preflight_v2 except the two refusal branches (400 invalid subject, 503 signing unavailable) now explicitly declare every permitted field and set additionalProperties false, closing the gap where injected keys were accepted in a refusal body. No other change.",
 "$defs": {
  "subject": {
   "type": "object",
   "additionalProperties": false,
   "required": [
    "address",
    "chain",
    "role"
   ],
   "properties": {
    "address": {
     "type": "string"
    },
    "chain": {
     "type": "string"
    },
    "role": {
     "enum": [
      "payer",
      "payee",
      "escrow_destination"
     ]
    }
   }
  },
  "manifest": {
   "type": "object",
   "additionalProperties": false,
   "required": [
    "url",
    "entry"
   ],
   "properties": {
    "url": {
     "const": "https://x402.nsgoods.org/proof/index.json"
    },
    "entry": {
     "const": "preflight"
    },
    "source_service": {
     "type": "string"
    }
   }
  },
  "component_common": {
   "type": "object",
   "additionalProperties": false,
   "required": [
    "component",
    "verdict",
    "reason_codes",
    "observed_at",
    "freshness_bound_seconds",
    "limitations",
    "subject_echo",
    "signer",
    "manifest",
    "component_digest",
    "component_signature"
   ],
   "properties": {
    "component": {
     "type": "string"
    },
    "verdict": {
     "type": "string"
    },
    "reason_codes": {
     "type": "array",
     "items": {
      "type": "string"
     },
     "minItems": 1
    },
    "observed_at": {
     "type": "string",
     "format": "date-time"
    },
    "freshness_bound_seconds": {
     "type": "integer"
    },
    "limitations": {
     "type": "array",
     "items": {
      "type": "string"
     },
     "minItems": 1
    },
    "subject_echo": {
     "$ref": "#/$defs/subject"
    },
    "signer": {
     "const": "0x57fF0F084Cba33e6761503f90eEF0Da9F159350c"
    },
    "manifest": {
     "$ref": "#/$defs/manifest"
    },
    "synthetic_condition": {
     "type": "boolean"
    },
    "synthetic_note": {
     "type": "string"
    },
    "component_digest": {
     "type": "string",
     "pattern": "^[0-9a-f]{64}$"
    },
    "component_signature": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]+$"
    }
   }
  }
 },
 "oneOf": [
  {
   "type": "object",
   "additionalProperties": false,
   "required": [
    "schema_version",
    "request",
    "components",
    "observation",
    "components_evaluated",
    "envelope"
   ],
   "properties": {
    "schema_version": {
     "const": "preflight_v3"
    },
    "request": {
     "type": "object",
     "additionalProperties": false,
     "required": [
      "request_id",
      "request_time",
      "subject"
     ],
     "properties": {
      "request_id": {
       "type": "string"
      },
      "request_time": {
       "type": "string",
       "format": "date-time"
      },
      "subject": {
       "$ref": "#/$defs/subject"
      }
     }
    },
    "components": {
     "type": "array",
     "minItems": 3,
     "maxItems": 3,
     "prefixItems": [
      {
       "allOf": [
        {
         "$ref": "#/$defs/component_common"
        }
       ],
       "properties": {
        "component": {
         "const": "payability"
        },
        "verdict": {
         "enum": [
          "PAYABLE",
          "NOT_PAYABLE",
          "not_evaluated"
         ]
        },
        "freshness_bound_seconds": {
         "const": 300
        }
       }
      },
      {
       "allOf": [
        {
         "$ref": "#/$defs/component_common"
        }
       ],
       "properties": {
        "component": {
         "const": "sanctions"
        },
        "verdict": {
         "enum": [
          "CLEAR",
          "MATCH",
          "not_evaluated"
         ]
        },
        "freshness_bound_seconds": {
         "const": 86400
        }
       }
      },
      {
       "allOf": [
        {
         "$ref": "#/$defs/component_common"
        }
       ],
       "properties": {
        "component": {
         "const": "trust"
        },
        "verdict": {
         "enum": [
          "DATA",
          "NO_DATA",
          "not_evaluated"
         ]
        },
        "freshness_bound_seconds": {
         "const": 3600
        }
       }
      }
     ],
     "items": false
    },
    "observation": {
     "type": "object",
     "additionalProperties": false,
     "required": [
      "mode",
      "spread_ms"
     ],
     "properties": {
      "mode": {
       "const": "sequential-within-one-request"
      },
      "spread_ms": {
       "type": "integer",
       "minimum": 0
      }
     }
    },
    "components_evaluated": {
     "type": "integer",
     "minimum": 0,
     "maximum": 3
    },
    "envelope": {
     "type": "object",
     "additionalProperties": false,
     "required": [
      "signer",
      "signature"
     ],
     "properties": {
      "signer": {
       "const": "0x57fF0F084Cba33e6761503f90eEF0Da9F159350c"
      },
      "signature": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]+$"
      }
     }
    }
   }
  },
  {
   "type": "object",
   "required": [
    "error",
    "http_status",
    "charged",
    "schema_version",
    "reason_codes"
   ],
   "properties": {
    "error": {
     "type": "string"
    },
    "detail": {
     "type": "string"
    },
    "http_status": {
     "const": 400
    },
    "charged": {
     "const": false
    },
    "schema_version": {
     "const": "preflight_v3"
    },
    "note": {
     "type": "string"
    },
    "reason_codes": {
     "type": "array",
     "items": {
      "type": "string"
     },
     "minItems": 1
    }
   },
   "additionalProperties": false
  },
  {
   "type": "object",
   "required": [
    "error",
    "http_status",
    "charged",
    "schema_version",
    "reason_codes"
   ],
   "properties": {
    "error": {
     "type": "string"
    },
    "detail": {
     "type": "string"
    },
    "http_status": {
     "const": 503
    },
    "charged": {
     "const": false
    },
    "schema_version": {
     "const": "preflight_v3"
    },
    "note": {
     "type": "string"
    },
    "reason_codes": {
     "type": "array",
     "items": {
      "type": "string"
     },
     "minItems": 1,
     "contains": {
      "const": "signing_unavailable"
     }
    }
   },
   "additionalProperties": false
  }
 ]
}