Clojars-MCP-Server

Instructions

Implementation Reference

• src/index.ts:189-244 (handler)

  Executes the tool logic: validates input, fetches maven-metadata.xml from Clojars, parses versions, checks if specified version exists, returns JSON result or error.

  } else if (request.params.name === 'check_clojars_version_exists') {
    if (!isValidVersionCheckArgs(request.params.arguments)) {
      throw new McpError(
        ErrorCode.InvalidParams,
        'Invalid arguments. Expected "dependency" in format "group/artifact" and "version"'
      );
    }
  
    const [group, artifact] = request.params.arguments.dependency.split('/');
    const version = request.params.arguments.version;
  
    try {
      const response = await this.axiosInstance.get<string>(
        `/${group.replace(/\./g, '/')}/${artifact}/maven-metadata.xml`
      );
  
      // Extract all versions from XML
      const versionsMatch = response.data.match(/<version>(.*?)<\/version>/g);
      const versions = versionsMatch?.map(v => v.replace(/<\/?version>/g, '')) || [];
  
      const exists = versions.includes(version);
  
      return {
        content: [
          {
            type: 'text',
            text: JSON.stringify(
              {
                dependency: `${group}/${artifact}`,
                version: version,
                exists: exists
              },
              null,
              2
            ),
          },
        ],
      };
    } catch (error) {
      if (axios.isAxiosError(error)) {
        const message = error.response?.status === 404
          ? `Dependency ${group}/${artifact} not found on Clojars`
          : `Clojars API error: ${error.message}`;
        
        return {
          content: [
            {
              type: 'text',
              text: message,
            },
          ],
          isError: true,
        };
      }
      throw error;
    }

• src/index.ts:90-107 (registration)

  Registers the tool in the ListTools response, including name, description, and input schema.

  {
    name: 'check_clojars_version_exists',
    description: 'Check if a specific version of a Clojars dependency exists',
    inputSchema: {
      type: 'object',
      properties: {
        dependency: {
          type: 'string',
          description: 'Clojars dependency name in format "group/artifact" (e.g. "metosin/reitit")',
        },
        version: {
          type: 'string',
          description: 'Version to check (e.g. "0.7.2")',
        },
      },
      required: ['dependency', 'version'],
    },
  },

• src/index.ts:93-106 (schema)

  Input schema definition for the tool parameters: dependency (group/artifact) and version.

  inputSchema: {
    type: 'object',
    properties: {
      dependency: {
        type: 'string',
        description: 'Clojars dependency name in format "group/artifact" (e.g. "metosin/reitit")',
      },
      version: {
        type: 'string',
        description: 'Version to check (e.g. "0.7.2")',
      },
    },
    required: ['dependency', 'version'],
  },

• src/index.ts:25-30 (helper)

  Helper function to validate the tool's input arguments (dependency format and version string).

  const isValidVersionCheckArgs = (args: any): args is { dependency: string; version: string } =>
    typeof args === 'object' &&
    args !== null &&
    typeof args.dependency === 'string' &&
    args.dependency.includes('/') &&
    typeof args.version === 'string';