{
  "status": "error",
  "code": 422,
  "error": {
    "type": "ValidationError",
    "message": "The request body contains invalid or missing fields.",
    "request_id": "req_x9y8z7w6v5u4",
    "timestamp": "2025-04-10T14:32:18Z",
    "documentation_url": "https://api.example.com/docs/errors#validation-error",
    "details": [
      {
        "field": "email",
        "value": "not-an-email",
        "code": "INVALID_FORMAT",
        "message": "Must be a valid email address.",
        "expected": "string matching RFC 5322 email format",
        "received": "not-an-email"
      },
      {
        "field": "username",
        "value": "",
        "code": "REQUIRED_FIELD",
        "message": "This field is required and cannot be empty.",
        "expected": "non-empty string (3–30 characters)",
        "received": ""
      },
      {
        "field": "age",
        "value": -5,
        "code": "OUT_OF_RANGE",
        "message": "Value must be between 0 and 150.",
        "expected": "integer >= 0 and <= 150",
        "received": -5
      },
      {
        "field": "role",
        "value": "superuser",
        "code": "INVALID_ENUM",
        "message": "Must be one of the allowed values.",
        "expected": ["admin", "editor", "viewer"],
        "received": "superuser"
      },
      {
        "field": "profile.bio",
        "value": null,
        "code": "INVALID_TYPE",
        "message": "Expected a string but received null.",
        "expected": "string",
        "received": "null"
      },
      {
        "field": "tags",
        "value": "developer",
        "code": "INVALID_TYPE",
        "message": "Expected an array but received a string.",
        "expected": "array of strings",
        "received": "string"
      }
    ]
  },
  "meta": {
    "api_version": "v1",
    "response_time_ms": 8,
    "rate_limit": {
      "limit": 1000,
      "remaining": 846,
      "reset_at": "2025-04-10T19:00:00Z"
    }
  }
}