NS Travel Information Server

Instructions

Implementation Reference

• src/services/NSApiService.ts:95-106 (handler)

  The core handler function that executes the tool logic by querying the NS Places API (/places-api/v2/ovfiets) for OV-fiets bike availability at the given station code.

  async getOVFiets(args: GetOVFietsArgs): Promise<OVFietsResponse> {
    this.ensureApiKeyConfigured();
    const response = await this.axiosInstance.get<OVFietsResponse>(
      NSApiService.ENDPOINTS.OVFIETS,
      {
        params: {
          station_code: args.stationCode
        }
      }
    );
    return response.data;
  }

• src/types.ts:395-406 (schema)

  TypeScript interface defining the input arguments (stationCode: string) and type guard function for validating get_ovfiets tool inputs.

  export interface GetOVFietsArgs {
    stationCode: string;
  }
  
  export function isValidOVFietsArgs(args: unknown): args is GetOVFietsArgs {
    if (!args || typeof args !== "object") {
      return false;
    }
  
    const typedArgs = args as Record<string, unknown>;
    return typeof typedArgs.stationCode === "string";
  }

• src/index.ts:136-147 (registration)

  Tool registration in the stdio server (src/index.ts), including name, description, and input schema advertised to MCP clients.

  name: 'get_ovfiets',
  description: 'Get OV-fiets availability at a train station',
  inputSchema: {
    type: 'object',
    properties: {
      stationCode: {
        type: 'string',
        description: 'Station code to check OV-fiets availability for (e.g., ASD for Amsterdam Centraal)',
      }
    },
    required: ['stationCode']
  }

• src/http-server.ts:264-276 (registration)

  Tool registration in the HTTP server (src/http-server.ts), including name, description, and input schema advertised to MCP clients.

    name: 'get_ovfiets',
    description: 'Get OV-fiets availability at a train station',
    inputSchema: {
      type: 'object',
      properties: {
        stationCode: {
          type: 'string',
          description: 'Station code to check OV-fiets availability for (e.g., ASD for Amsterdam Centraal)',
        }
      },
      required: ['stationCode']
    }
  },

• src/http-server.ts:448-457 (helper)

  Dispatch handler in HTTP server that validates args and calls the NSApiService.getOVFiets method.

  case 'get_ovfiets': {
    if (!isValidOVFietsArgs(rawArgs)) {
      throw ResponseFormatter.createMcpError(
        ErrorCode.InvalidParams,
        'Invalid arguments for get_ovfiets'
      );
    }
    const data = await this.nsApiService.getOVFiets(rawArgs);
    return ResponseFormatter.formatSuccess(data);
  }