ShipStation API MCP Server

Implementation Reference

• src/tools/shipment-tools.js:40-52 (handler)

  The handler function for the 'get_shipment' tool. It takes a shipmentId parameter, fetches the shipment details using shipStationClient.getShipment, stringifies the result to JSON, and returns it in the expected MCP format, or returns an error message if the call fails.

  handler: async ({ shipmentId }) => {
    try {
      const shipment = await shipStationClient.getShipment(shipmentId);
      return {
        content: [{ type: "text", text: JSON.stringify(shipment, null, 2) }]
      };
    } catch (error) {
      return {
        content: [{ type: "text", text: error.message }],
        isError: true
      };
    }
  }

• src/tools/shipment-tools.js:37-39 (schema)

  Zod input schema for the 'get_shipment' tool, defining the required shipmentId as a number.

  schema: {
    shipmentId: z.number().describe("Shipment ID to retrieve")
  },

• src/tools/shipment-tools.js:34-53 (registration)

  The complete 'get_shipment' tool object definition, which is part of the shipmentTools array exported and later spread into the MCP server's tool registration.

  {
    name: "get_shipment",
    description: "Get details for a specific shipment",
    schema: {
      shipmentId: z.number().describe("Shipment ID to retrieve")
    },
    handler: async ({ shipmentId }) => {
      try {
        const shipment = await shipStationClient.getShipment(shipmentId);
        return {
          content: [{ type: "text", text: JSON.stringify(shipment, null, 2) }]
        };
      } catch (error) {
        return {
          content: [{ type: "text", text: error.message }],
          isError: true
        };
      }
    }
  },

• src/server.js:174-191 (registration)

  Generic MCP server tool registration code that spreads all tool arrays (including shipmentTools which contains get_shipment) and registers each tool using server.tool().

  [
    ...orderTools,
    ...shipmentTools,
    ...carrierTools,
    ...warehouseTools,
    ...productTools,
    ...customerTools,
    ...storeTools,
    ...webhookTools,
    ...fulfillmentTools
  ].forEach(tool => {
    server.tool(
      tool.name,
      tool.schema,
      tool.handler,
      { description: tool.description }
    );
  });

• src/api-client.js:89-91 (helper)

  API client helper method getShipment used by the tool handler to make the actual HTTP GET request to ShipStation's /shipments/{shipmentId} endpoint.

  async getShipment(shipmentId) {
    return this.request('GET', `/shipments/${shipmentId}`);
  }