NASA MCP Server

Instructions

Implementation Reference

• src/handlers/jpl/nhats.ts:14-75 (handler)

  The `nhatsHandler` function implements the core logic of the `jpl_nhats` tool. It queries the JPL NHATS API at `https://ssd-api.jpl.nasa.gov/nhats.api`, transforms input parameters, fetches data using axios, creates resource URIs like `jpl://nhats/object/{des}`, stores the JSON response as a resource, and returns formatted content or error.

  export async function nhatsHandler(args: Record<string, any>) {
    try {
      // Base URL for the NHATS API
      const baseUrl = 'https://ssd-api.jpl.nasa.gov/nhats.api';
      
      // Validate parameters if needed
      // Parameters are fairly flexible in this API, so minimal validation is needed
      
      // Transform parameter names from underscore to hyphenated format
      const transformedParams = transformParamsToHyphenated(args);
      
      // Make the API request
      const response = await axios.get(baseUrl, { params: transformedParams });
      const data = response.data;
      
      // Create a resource URI that represents this query
      let resourceUri: string;
      
      if (args.des) {
        // Object mode - query for a specific object
        resourceUri = `jpl://nhats/object/${args.des}`;
      } else if (args.spk) {
        // Object mode - query for a specific object by SPK-ID
        resourceUri = `jpl://nhats/object/${args.spk}`;
      } else {
        // Summary mode - query for a list of objects with constraints
        const constraints = Object.entries(args)
          .map(([key, value]) => `${key}=${value}`)
          .join('&');
        
        resourceUri = `jpl://nhats/summary${constraints ? '?' + constraints : ''}`;
      }
      
      // Add response to resources
      addResource(resourceUri, {
        name: args.des || args.spk 
          ? `NHATS data for object: ${args.des || args.spk}`
          : 'NHATS summary data',
        mimeType: "application/json",
        text: JSON.stringify(data, null, 2)
      });
      
      // Format the response
      return {
        content: [{
          type: "text",
          text: JSON.stringify(data, null, 2)
        }]
      };
    } catch (error: any) {
      return {
        content: [{
          type: "text",
          text: `Error accessing JPL NHATS API: ${error.message}`
        }],
        isError: true
      };
    }
  }
  
  // Export default for dynamic imports
  export default nhatsHandler; 

• src/index.ts:518-523 (registration)

  Registration of the `jpl_nhats` tool in the `tools/manifest` response, specifying its name, internal ID `jpl/nhats`, and description.

    name: "jpl_nhats",
    id: "jpl/nhats",
    description: "Human-accessible NEOs (Near-Earth Objects) data"
  },
  {
    name: "jpl_cad",

• src/index.ts:1088-1131 (schema)

  Detailed input schema and description for the `jpl_nhats` tool defined in the `tools/list` handler response, including parameters like `dv`, `dur`, `des`, `spk`, etc.

    name: "jpl_nhats",
    description: "Human-accessible NEOs (Near-Earth Objects) data",
    inputSchema: {
      type: "object",
      properties: {
        dv: {
          type: "number",
          description: "Minimum total delta-V (km/s). Values: 4-12, default: 12"
        },
        dur: {
          type: "number",
          description: "Minimum total mission duration (days). Values: 60-450, default: 450"
        },
        stay: {
          type: "number",
          description: "Minimum stay time (days). Values: 8, 16, 24, 32, default: 8"
        },
        launch: {
          type: "string",
          description: "Launch window (year range). Values: 2020-2025, 2025-2030, 2030-2035, 2035-2040, 2040-2045, 2020-2045, default: 2020-2045"
        },
        h: {
          type: "number",
          description: "Object's maximum absolute magnitude (mag). Values: 16-30"
        },
        occ: {
          type: "number",
          description: "Object's maximum orbit condition code. Values: 0-8"
        },
        des: {
          type: "string",
          description: "Object designation (e.g., '2000 SG344' or '433')"
        },
        spk: {
          type: "string",
          description: "Object SPK-ID (e.g., '2000433')"
        },
        plot: {
          type: "boolean",
          description: "Include base-64 encoded plot image"
        }
      }
    }
  },