NASA MCP Server

Instructions

Implementation Reference

• src/handlers/nasa/neo.ts:18-95 (handler)

  Core handler function `nasaNeoHandler` that executes the nasa_neo tool logic: fetches NEO data by date range or asteroid ID from NASA API, stores as resource, formats output.

  export async function nasaNeoHandler(params: NeoParams) {
    try {
      // If we're looking for a specific asteroid by ID
      if (params.asteroid_id) {
        const endpoint = `/neo/rest/v1/neo/${params.asteroid_id}`;
        const result = await nasaApiRequest(endpoint, {});
        
        // Store the result as a resource
        addResource(`nasa://neo/${params.asteroid_id}`, {
          name: `Asteroid: ${result.name}`,
          mimeType: 'application/json',
          text: JSON.stringify(result, null, 2)
        });
        
        // Return formatted result
        return {
          content: [
            {
              type: "text",
              text: formatSingleAsteroidText(result)
            }
          ],
          isError: false
        };
      }
      
      // Default to today if no dates specified
      let startDate = params.start_date;
      let endDate = params.end_date;
      
      if (!startDate) {
        const today = new Date();
        startDate = today.toISOString().split('T')[0];
      }
      
      // If no end_date, use start_date (same day)
      if (!endDate) {
        endDate = startDate;
      }
      
      // API limits feed to 7 days
      const maxDays = 7;
      const start = new Date(startDate);
      const end = new Date(endDate);
      const daysDiff = Math.floor((end.getTime() - start.getTime()) / (1000 * 60 * 60 * 24));
      
      if (daysDiff > maxDays) {
        return {
          content: [
            {
              type: "text",
              text: `Error: Date range too large. NEO feed is limited to ${maxDays} days.`
            }
          ],
          isError: true
        };
      }
      
      // Call the NASA NEO API
      const endpoint = `/neo/rest/v1/feed?start_date=${startDate}&end_date=${endDate}`;
      const result = await nasaApiRequest(endpoint, {});
      
      // Process and format the results
      return processNeoFeedResults(result, startDate, endDate);
    } catch (error: any) {
      console.error('Error in NEO handler:', error);
      
      return {
        content: [
          {
            type: "text",
            text: `Error retrieving NEO data: ${error.message}`
          }
        ],
        isError: true
      };
    }
  }

• src/handlers/nasa/neo.ts:6-10 (schema)

  Zod schema `neoParamsSchema` defining input parameters for the nasa_neo tool.

  export const neoParamsSchema = z.object({
    start_date: z.string().optional(),
    end_date: z.string().optional(),
    asteroid_id: z.string().optional()
  });

• src/index.ts:728-748 (registration)

  Tool `nasa_neo` definition and input schema in the `tools/list` handler response.

    name: "nasa_neo",
    description: "Near Earth Object Web Service - information about asteroids",
    inputSchema: {
      type: "object",
      properties: {
        start_date: {
          type: "string",
          description: "Start date for asteroid search (YYYY-MM-DD)"
        },
        end_date: {
          type: "string",
          description: "End date for asteroid search (YYYY-MM-DD)"
        },
        asteroid_id: {
          type: "string",
          description: "ID of a specific asteroid"
        }
      },
      required: ["start_date", "end_date"]
    }
  },

• src/index.ts:1496-1509 (registration)

  Direct MCP request handler registration for method `nasa/neo`, dispatching to `handleToolCall`.

  // NEO Handler
  server.setRequestHandler(
    z.object({ 
      method: z.literal("nasa/neo"),
      params: z.object({
        start_date: z.string().optional(),
        end_date: z.string().optional(),
        asteroid_id: z.string().optional()
      }).optional()
    }),
    async (request) => {
      return await handleToolCall("nasa/neo", request.params || {});
    }
  );

• src/index.ts:1853-1895 (registration)

  Dynamic handler loading in `handleToolCall`: imports `./handlers/nasa/neo.js` and calls default export (`nasaNeoHandler`) for `nasa_neo` tool.

  if (internalToolId.startsWith("nasa/")) {
    // Extract the NASA API endpoint name
    const endpoint = internalToolId.split("/")[1];
    const normalizedEndpoint = endpoint.replace(/-/g, '_'); // Normalize dashes for handler lookup if needed
  
    // Log endpoint for debugging
    serverInstance?.sendLoggingMessage({
      level: "info",
      data: `NASA Endpoint: ${endpoint} (Normalized: ${normalizedEndpoint})`,
    });
  
    try {
      // Dynamic import for NASA handlers using the original slash format path
      const handlerModule = await import(`./handlers/nasa/${endpoint}.js`);
      serverInstance?.sendLoggingMessage({
        level: "info",
        data: `Successfully imported handler module for: ./handlers/nasa/${endpoint}.js`,
      });
  
      // Try different potential handler function names
      const handlerFunctionName = `nasa${endpoint.charAt(0).toUpperCase() + endpoint.slice(1).replace(/-/g, '_')}Handler`; // e.g. nasaMars_roverHandler
      const simpleHandlerName = `${endpoint.replace(/-/g, '_')}Handler`; // e.g. mars_roverHandler
  
      const handlerFunction = handlerModule.default || 
                             handlerModule[handlerFunctionName] || 
                             handlerModule[simpleHandlerName];
  
      if (typeof handlerFunction === 'function') {
        serverInstance?.sendLoggingMessage({
          level: "info",
          data: `Executing handler function for ${endpoint}`,
        });
        return await handlerFunction(args);
      } else {
        serverInstance?.sendLoggingMessage({
          level: "info",
          data: `No handler function found in module: ${JSON.stringify(Object.keys(handlerModule))}`,
        });
        throw new Error(`No handler function found for NASA endpoint: ${normalizedEndpoint}`);
      }
    } catch (importError) {
      throw new Error(`Failed to import handler for NASA endpoint: ${normalizedEndpoint}. Error: ${importError instanceof Error ? importError.message : String(importError)}`);
    }