alibaba/nacos · error · IllegalStateException

Invalid URL: ${url}

Error message

Invalid URL: ${url}

What it means

Thrown by McpExternalDataAdaptor.generateRemoteServiceConfig when a remote's URL cannot be parsed into components (scheme/host/port/path). Any exception during parsing is wrapped as IllegalStateException with the offending URL. This happens while adapting registry remotes into Nacos front-endpoint configs.

Source

Thrown at ai/src/main/java/com/alibaba/nacos/ai/service/McpExternalDataAdaptor.java:345

                    (components.getPort() > 0) ? components.getPort() : (isHttps ? 443 : 80);
                String endpointData = components.getHost() + ":" + effectivePort;
                FrontEndpointConfig cfg = new FrontEndpointConfig();
                cfg.setEndpointData(endpointData);
                cfg.setPath(
                    StringUtils.isNotBlank(components.getPath()) ? components.getPath() : "/");
                cfg.setType(remote.getType());
                cfg.setProtocol(components.getScheme());
                cfg.setEndpointType(AiConstants.Mcp.MCP_FRONT_ENDPOINT_TYPE_TO_BACK);
                cfg.setHeaders(remote.getHeaders());
                endpoints.add(cfg);
                
                // Use first remote's path as export path
                if (remoteConfig.getExportPath() == null) {
                    remoteConfig
                        .setExportPath(components.getPath() != null ? components.getPath() : "/");
                }
            } catch (Exception e) {
                throw new IllegalStateException("Invalid URL: " + url, e);
            }
        }
        
        remoteConfig.setFrontEndpointConfigList(endpoints);
        return remoteConfig;
    }
    
    /**
     * Parse URL into components (scheme, host, port, path).
     * Manual parsing without using URI class.
     *
     * @param url the URL string to parse
     * @return UrlComponents containing scheme, host, port, and path
     */
    private UrlComponents parseUrlComponents(String url) {
        String scheme = null;
        String host = null;
        int port = -1;

View on GitHub (pinned to 9b989acdf1)

Solutions

1. Validate each remote URL is absolute with a scheme (http/https) before adapting.
2. Sanitize/filter registry entries whose url is blank or missing '://'.
3. Pre-check with new URI(url) client-side and skip or report malformed entries.

Example fix

// before
remote.setUrl("localhost:8080/mcp"); // no scheme -> parse fails

// after
remote.setUrl("https://localhost:8080/mcp");

try { URI u = new URI(remote.getUrl()); if (u.getScheme() == null || u.getHost() == null) throw new IllegalArgumentException("malformed remote url"); } catch (URISyntaxException ex) { throw new IllegalArgumentException(ex); }

boolean isAbsoluteRemote(Remote r) { try { URI u = new URI(r.getUrl()); return u.getScheme() != null && u.getHost() != null; } catch (Exception e) { return false; } }

try { adaptor.adaptExternalDataToNacosMcpServerFormat(req); }
catch (IllegalStateException e) { if (e.getMessage().startsWith("Invalid URL")) skipMalformedRemote(); }

When it happens

Trigger: A registry server detail carries a remote whose url field is malformed (missing scheme, unparseable host, etc.); the URL string is null or lacks '://'; the manual parseUrlComponents logic cannot split it.

Common situations: Upstream registry data has a relative or malformed URL; a remote URL uses an unsupported scheme; a migration left an empty url string.

Related errors

• MCP server not found in registry: ${externalId}
• HTTP ${code} when fetching ${pageUrl}
• Failed to parse response body
• URL is blank
• MCP server external id is blank

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/9d3625de5227d198. Report an issue: GitHub.