eBird MCP Server

Instructions

Implementation Reference

• src/index.ts:140-156 (handler)

  The asynchronous handler function that implements the core logic of the 'get_nearby_observations' tool. It constructs query parameters from inputs and calls the eBird API's /data/obs/geo/recent endpoint via makeRequest.

  async (args) => {
    const params: Record<string, string | number | boolean> = {
      lat: args.lat,
      lng: args.lng,
      back: args.back,
      dist: args.dist,
      hotspot: args.hotspot,
      includeProvisional: args.include_provisional,
      sort: args.sort,
      sppLocale: args.spp_locale,
    };
    if (args.cat) params.cat = args.cat;
    if (args.max_results) params.maxResults = args.max_results;
  
    const result = await makeRequest("/data/obs/geo/recent", params);
    return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
  }

• src/index.ts:128-139 (schema)

  Zod input schema defining parameters for latitude, longitude, search radius, time frame, filters, and sorting for the get_nearby_observations tool.

  {
    lat: z.number().min(-90).max(90).describe("Latitude"),
    lng: z.number().min(-180).max(180).describe("Longitude"),
    back: z.number().min(1).max(30).default(14).describe("Number of days back to fetch"),
    cat: z.string().optional().describe("Taxonomic category filter"),
    dist: z.number().min(0).max(50).default(25).describe("Search radius in kilometers"),
    hotspot: z.boolean().default(false).describe("Only fetch from hotspots"),
    include_provisional: z.boolean().default(false).describe("Include unreviewed observations"),
    max_results: z.number().min(1).max(10000).optional().describe("Maximum observations to return"),
    sort: z.enum(["date", "species"]).default("date").describe("Sort by date or species"),
    spp_locale: z.string().default("en").describe("Language for common names"),
  },

• src/index.ts:125-157 (registration)

  MCP server.tool registration for 'get_nearby_observations', including name, description, schema, and handler.

  server.tool(
    "get_nearby_observations",
    "Get recent observations near a geographic location.",
    {
      lat: z.number().min(-90).max(90).describe("Latitude"),
      lng: z.number().min(-180).max(180).describe("Longitude"),
      back: z.number().min(1).max(30).default(14).describe("Number of days back to fetch"),
      cat: z.string().optional().describe("Taxonomic category filter"),
      dist: z.number().min(0).max(50).default(25).describe("Search radius in kilometers"),
      hotspot: z.boolean().default(false).describe("Only fetch from hotspots"),
      include_provisional: z.boolean().default(false).describe("Include unreviewed observations"),
      max_results: z.number().min(1).max(10000).optional().describe("Maximum observations to return"),
      sort: z.enum(["date", "species"]).default("date").describe("Sort by date or species"),
      spp_locale: z.string().default("en").describe("Language for common names"),
    },
    async (args) => {
      const params: Record<string, string | number | boolean> = {
        lat: args.lat,
        lng: args.lng,
        back: args.back,
        dist: args.dist,
        hotspot: args.hotspot,
        includeProvisional: args.include_provisional,
        sort: args.sort,
        sppLocale: args.spp_locale,
      };
      if (args.cat) params.cat = args.cat;
      if (args.max_results) params.maxResults = args.max_results;
  
      const result = await makeRequest("/data/obs/geo/recent", params);
      return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
    }
  );

• src/index.ts:19-36 (helper)

  Utility function used by all tools, including get_nearby_observations, to perform authenticated HTTP requests to the eBird API.

  async function makeRequest(endpoint: string, params: Record<string, string | number | boolean> = {}): Promise<unknown> {
    const url = new URL(`${BASE_URL}${endpoint}`);
    Object.entries(params).forEach(([key, value]) => {
      if (value !== undefined && value !== null) {
        url.searchParams.append(key, String(value));
      }
    });
  
    const response = await fetch(url.toString(), {
      headers: { "X-eBirdApiToken": API_KEY! },
    });
  
    if (!response.ok) {
      throw new Error(`eBird API error: ${response.status} ${response.statusText}`);
    }
  
    return response.json();
  }