Nessus MCP Server

Instructions

Implementation Reference

• src/tools/scans.ts:179-223 (handler)

  The primary handler for the 'get_scan_results' tool. Validates the scan_id argument, fetches results via getScanResults helper, handles errors, formats output using formatScanResults, and returns MCP-formatted content.

  export const getScanResultsToolHandler = async (args: Record<string, unknown>) => {
    try {
      // Validate arguments
      const scanId = validateScanId(args.scan_id);
  
      // Get scan results
      const results = await getScanResults(scanId);
  
      // Check if there was an error
      if ('error' in results) {
        return {
          content: [
            {
              type: 'text',
              text: `Error: ${results.error}`
            }
          ],
          isError: true
        };
      }
  
      // Format the results
      const formattedResults = formatScanResults(results);
  
      return {
        content: [
          {
            type: 'text',
            text: formattedResults
          }
        ]
      };
    } catch (error) {
      const mcpError = handleNessusApiError(error);
      return {
        content: [
          {
            type: 'text',
            text: `Error: ${mcpError.message}`
          }
        ],
        isError: true
      };
    }
  };

• src/tools/scans.ts:164-177 (schema)

  The input schema definition for the 'get_scan_results' tool, specifying the required scan_id parameter.

  export const getScanResultsToolSchema = {
    name: 'get_scan_results',
    description: 'Get the results of a completed scan',
    inputSchema: {
      type: 'object',
      properties: {
        scan_id: {
          type: 'string',
          description: 'ID of the scan to get results for'
        }
      },
      required: ['scan_id']
    }
  };

• src/index.ts:103-104 (registration)

  Tool dispatch registration in the main CallToolRequestSchema handler switch statement.

  case 'get_scan_results':
    return await getScanResultsToolHandler(args);

• src/index.ts:75-84 (registration)

  Tool schema registration in the ListToolsRequestSchema handler, where getScanResultsToolSchema is listed among available tools.

    tools: [
      listScanTemplatesToolSchema,
      startScanToolSchema,
      getScanStatusToolSchema,
      getScanResultsToolSchema,
      listScansToolSchema,
      getVulnerabilityDetailsToolSchema,
      searchVulnerabilitiesToolSchema
    ]
  };

• src/nessus-api.ts:98-105 (helper)

  Core helper function called by the tool handler to retrieve scan results from Nessus API (mock or real).

  export const getScanResults = async (scanId: string) => {
    if (config.useMock) {
      return getMockScanResults(scanId);
    }
  
    // Real API implementation would go here
    throw new Error("Real API not implemented");
  };