By default, a 400 (bad request) is returned if a query, header or body input can't be decoded (for any reason), or if decoding a path capture ends with an error.
By default, a 400 (bad request) is returned if a query, header or body input can't be decoded (for any reason), or if decoding a path capture ends with an error.
Otherwise (e.g. if the method, a path segment, or path capture is missing or there's a mismatch), a "no match" is returned, which is a signal to try the next endpoint.