# Calling initialize() with no Authorization header at all

client.initialize() with no bearer token threw:
  java.lang.RuntimeException: Client failed to initialize by explicit API call

  caused by [0]: io.modelcontextprotocol.client.transport.McpHttpClientTransportAuthorizationException: Authorization error when sending message

Spring Security's filter chain rejects the request with HTTP 401 before the
DispatcherServlet ever hands it to the MCP server -- there is no 'anonymous tools/list'
response to intercept, because the initialize handshake itself never completes.