chargeable_weight_calculator

Instructions

Implementation Reference

• src/tools.ts:95-99 (handler)

  The handler function that executes chargeable_weight_calculator logic. Calls the external FreightUtils API endpoint 'chargeable-weight' via apiGet, passing length_cm, width_cm, height_cm, gross_weight_kg, pieces, and factor as query parameters.

  handler: async (args) =>
    apiGet('chargeable-weight', {
      l: args.length_cm, w: args.width_cm, h: args.height_cm,
      gw: args.gross_weight_kg, pcs: args.pieces, factor: args.factor,
    }),

• src/tools.ts:84-91 (schema)

  Zod schema defining input validation for chargeable_weight_calculator. Accepts length_cm, width_cm, height_cm, gross_weight_kg (required positives), plus optional pieces (default 1) and factor (default 6000 IATA standard). Uses .strict() to reject unknown keys.

  schema: z.object({
    length_cm: z.number().positive().describe('Length in centimetres'),
    width_cm: z.number().positive().describe('Width in centimetres'),
    height_cm: z.number().positive().describe('Height in centimetres'),
    gross_weight_kg: z.number().positive().describe('Actual gross weight in kilograms'),
    pieces: z.number().int().positive().optional().describe('Number of identical pieces (default: 1)'),
    factor: z.number().int().positive().optional().describe('Volumetric divisor (default: 6000 IATA standard, DHL uses 5000)'),
  }).strict(),

• src/tools.ts:713-715 (registration)

  The tool is registered in the ALL_TOOLS array, which is iterated by the server to register each tool with the MCP SDK via server.tool().

  export const ALL_TOOLS: ToolDef[] = [
    cbmCalculator,
    chargeableWeightCalculator,

• src/server.ts:18-41 (registration)

  Server registration: iterates ALL_TOOLS and calls server.tool() for each tool definition, wrapping handler results in text content for MCP response protocol.

  // Register every tool
  for (const tool of ALL_TOOLS) {
    server.tool(
      tool.name,
      tool.description,
      tool.schema.shape,
      tool.annotations,
      async (args: Record<string, unknown>) => {
        try {
          const result = await tool.handler(args);
          return {
            content: [
              { type: 'text' as const, text: JSON.stringify(result, null, 2) },
            ],
          };
        } catch (err: unknown) {
          const message = err instanceof Error ? err.message : String(err);
          return {
            content: [{ type: 'text' as const, text: `Error: ${message}` }],
            isError: true,
          };
        }
      },
    );

• src/api.ts:7-24 (helper)

  The apiGet helper function used by the chargeable_weight_calculator handler to make GET requests to the external FreightUtils API.

  export async function apiGet(endpoint: string, params: Record<string, unknown>): Promise<unknown> {
    const url = new URL(`${BASE_URL}/${endpoint}`);
    for (const [k, v] of Object.entries(params)) {
      if (v === undefined || v === null || v === '') continue;
      url.searchParams.set(k, String(v));
    }
  
    const res = await fetch(url.toString(), {
      headers: { 'Accept': 'application/json' },
    });
  
    if (!res.ok) {
      const body = await res.text();
      throw new Error(`FreightUtils API error ${res.status}: ${body}`);
    }
  
    return res.json();
  }