| RequestExceptionInterface | Interface for Request exceptions. |
| BadRequestException | Raised when a user sends a malformed request. |
| ConflictingHeadersException | The HTTP request contains headers with conflicting information. |
| JsonException | Thrown by Request::toArray() when the content cannot be JSON-decoded. |
| SuspiciousOperationException | Raised when a user has performed an operation that should be considered suspicious from a security perspective. |