Berlin Transport MCP Server

Implementation Reference

• src/index.ts:42-53 (handler)

  Handler function that fetches departures from the VBB Transport API for a given stop ID, optionally limiting the number of results, and returns the JSON data as text content.

  async ({ stop_id, results }) => {
    const url = new URL(`/stops/${stop_id}/departures`, VBB_API_BASE);
    if (results) {
      url.searchParams.set("results", String(results));
    }
  
    const response = await fetch(url);
    const data = await response.json();
    return {
      content: [{ type: "text", text: JSON.stringify(data, null, 2) }],
    };
  }

• src/index.ts:38-41 (schema)

  Zod schema defining the input parameters for the get_departures tool: required stop_id (string) and optional results (number).

  {
    stop_id: z.string().describe("Stop ID to get departures for"),
    results: z.number().optional().describe("Number of results to return"),
  },

• src/index.ts:37-54 (registration)

  Registration of the get_departures tool on the MCP server using this.server.tool(name, schema, handler).

    "get_departures",
    {
      stop_id: z.string().describe("Stop ID to get departures for"),
      results: z.number().optional().describe("Number of results to return"),
    },
    async ({ stop_id, results }) => {
      const url = new URL(`/stops/${stop_id}/departures`, VBB_API_BASE);
      if (results) {
        url.searchParams.set("results", String(results));
      }
  
      const response = await fetch(url);
      const data = await response.json();
      return {
        content: [{ type: "text", text: JSON.stringify(data, null, 2) }],
      };
    }
  );