{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Receipt Schema",
  "description": "Execution receipt with cryptographic sealing",
  "type": "object",
  "required": [
    "schema_version",
    "sequence_number",
    "receipt_id",
    "previous_receipt_hash",
    "agent_id",
    "capability_id",
    "instruction_hash",
    "action",
    "input_hash",
    "output_hash",
    "runtime_identity",
    "runtime_version",
    "source_commit",
    "environment_hash",
    "timestamp",
    "monotonic_counter",
    "status",
    "signature"
  ],
  "properties": {
    "schema_version": {
      "type": "string",
      "enum": ["1.0"],
      "description": "Receipt schema version"
    },
    "sequence_number": {
      "type": "integer",
      "description": "Monotonic sequence in receipt chain",
      "minimum": 0
    },
    "receipt_id": {
      "type": "string",
      "description": "Unique receipt identifier",
      "minLength": 32,
      "maxLength": 64
    },
    "receipt_hash": {
      "type": "string",
      "description": "SHA-256 hash of this receipt",
      "pattern": "^[a-f0-9]{64}$"
    },
    "previous_receipt_hash": {
      "type": "string",
      "description": "Hash of previous receipt in chain (or zeros for first)",
      "pattern": "^[a-f0-9]{64}$"
    },
    "agent_id": {
      "type": "string",
      "description": "Agent that executed this action",
      "minLength": 1,
      "maxLength": 50
    },
    "capability_id": {
      "type": "string",
      "description": "Capability under which this action was performed",
      "minLength": 32
    },
    "instruction_hash": {
      "type": "string",
      "description": "SHA-256 hash of the instruction executed",
      "pattern": "^[a-f0-9]{64}$"
    },
    "action": {
      "type": "string",
      "description": "Action performed (dispatch, verify, execute, etc.)",
      "minLength": 1,
      "maxLength": 50
    },
    "input_hash": {
      "type": "string",
      "description": "SHA-256 hash of input to this action",
      "pattern": "^[a-f0-9]{64}$"
    },
    "output_hash": {
      "type": "string",
      "description": "SHA-256 hash of output from this action",
      "pattern": "^[a-f0-9]{64}$"
    },
    "runtime_identity": {
      "type": "string",
      "description": "Identity of the runtime that executed this",
      "minLength": 1,
      "maxLength": 50
    },
    "runtime_version": {
      "type": "string",
      "description": "Version string of runtime",
      "pattern": "^\\d+\\.\\d+\\.\\d+.*$"
    },
    "source_commit": {
      "type": "string",
      "description": "Git commit hash of source code",
      "pattern": "^[a-f0-9]{40}$"
    },
    "environment_hash": {
      "type": "string",
      "description": "Hash of environment variables and config at execution time",
      "pattern": "^[a-f0-9]{64}$"
    },
    "timestamp": {
      "type": "integer",
      "description": "Unix timestamp of execution",
      "minimum": 0
    },
    "monotonic_counter": {
      "type": "integer",
      "description": "System monotonic counter (for causality)",
      "minimum": 0
    },
    "status": {
      "type": "string",
      "enum": ["success", "failure", "pending", "cancelled"],
      "description": "Execution status"
    },
    "error_message": {
      "type": ["string", "null"],
      "description": "Error message if status is failure"
    },
    "performance_metrics": {
      "type": "object",
      "description": "Optional performance data",
      "properties": {
        "wall_time_ms": { "type": "number" },
        "cpu_time_ms": { "type": "number" },
        "memory_peak_bytes": { "type": "integer" }
      }
    },
    "signature": {
      "type": "string",
      "description": "Ed25519 signature of receipt",
      "minLength": 128,
      "maxLength": 128,
      "pattern": "^[a-f0-9]{128}$"
    },
    "sealed": {
      "type": "boolean",
      "description": "Whether this receipt is WORM-sealed"
    }
  },
  "additionalProperties": false
}