LocalTides MCP Server

Instructions

Implementation Reference

• src/services/noaa-service.ts:125-160 (handler)

  Core handler function that implements the logic to retrieve NOAA stations list from the metadata API, processing parameters and constructing the API request.

  async getStations(params: Record<string, any>): Promise<any> {
    const { 
      type, 
      name, 
      lat_min, 
      lat_max, 
      lon_min, 
      lon_max, 
      state, 
      limit, 
      offset, 
      sort_by, 
      sort_order, 
      ...rest 
    } = params;
    
    const endpoint = '/stations.' + (rest.format || 'json');
    
    // Build query parameters with all the filters
    const queryParams: Record<string, any> = { ...rest };
    
    // Add filters only if they are defined
    if (type) queryParams.type = type;
    if (name) queryParams.name = name;
    if (lat_min !== undefined) queryParams.lat_min = lat_min;
    if (lat_max !== undefined) queryParams.lat_max = lat_max;
    if (lon_min !== undefined) queryParams.lon_min = lon_min;
    if (lon_max !== undefined) queryParams.lon_max = lon_max;
    if (state) queryParams.state = state;
    if (limit !== undefined) queryParams.limit = limit;
    if (offset !== undefined) queryParams.offset = offset;
    if (sort_by) queryParams.sort_by = sort_by;
    if (sort_order) queryParams.sort_order = sort_order;
    
    return this.fetchMetadataApi(endpoint, queryParams);
  }

• src/interfaces/noaa.ts:100-114 (schema)

  Zod schema for validating input parameters to the get_stations tool.

  export const GetStationsSchema = z.object({
    type: z.string().optional().describe('Station type (waterlevels, currents, etc.)'),
    units: UnitsSchema,
    format: z.enum(['json', 'xml']).optional().describe('Output format (json, xml)'),
    name: z.string().optional().describe('Filter stations by name (partial match)'),
    lat_min: z.number().optional().describe('Minimum latitude boundary'),
    lat_max: z.number().optional().describe('Maximum latitude boundary'),
    lon_min: z.number().optional().describe('Minimum longitude boundary'),
    lon_max: z.number().optional().describe('Maximum longitude boundary'),
    state: z.string().optional().describe('Filter stations by state code (e.g., CA, NY)'),
    limit: z.number().optional().describe('Maximum number of stations to return'),
    offset: z.number().optional().describe('Number of stations to skip for pagination'),
    sort_by: z.enum(['name', 'id', 'state']).optional().describe('Field to sort results by'),
    sort_order: z.enum(['asc', 'desc']).optional().describe('Sort order (ascending or descending)'),
  });

• src/server/mcp-server.ts:84-91 (registration)

  Tool registration in MCP server: defines the MCPTool for get_stations including name, description, schema, and handler delegating to noaaService.

  const getStations: MCPTool = {
    name: "get_stations",
    description: "Get list of stations",
    inputSchema: GetStationsSchema,
    handler: async (params) => {
      return this.noaaService.getStations(params);
    }
  };

• src/tools/station-tools.ts:15-34 (registration)

  Alternative tool registration using FastMCP.addTool for get_stations, with inline schema and execute handler.

  server.addTool({
    name: 'get_stations',
    description: 'Get list of stations',
    parameters: z.object({
      type: z.string().optional().describe('Station type (waterlevels, currents, etc.)'),
      format: z.enum(['json', 'xml']).optional().describe('Output format (json, xml)'),
      units: UnitsSchema,
    }),
    execute: async (params) => {
      try {
        const result = await noaaService.getStations(params);
        return JSON.stringify(result);
      } catch (error) {
        if (error instanceof Error) {
          throw new Error(`Failed to get stations: ${error.message}`);
        }
        throw new Error('Failed to get stations');
      }
    }
  });