Connect with USPS Using C#/.NET and EasyPost

Using C#/.NET to Integrate with USPS?

You can't do it through USPS. They use SOAP/XML for their endpoints with absolutely no client libraries or documentation to support you, but you can use Easypost to connect to USPS today using C#/.NET.

With EasyPost's USPS C#/.NET API, you can:

  • Print labels at the industry's lowest price
  • Track every outbound (or inbound) package
  • Verify every address, domestic or international
  • Shop for rates across your shipping accounts
  • Automate package insurance with low premiums
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using EasyPost;
using EasyPost.Models.API;
using EasyPost.Parameters;
using Newtonsoft.Json;

namespace EasyPostExamples
    public class Examples
        public static async Task Main()
            var client = new EasyPost.Client("EASYPOST_API_KEY");

            Parcel parcel = await client.Parcel.Create(
              new Parameters.Parcel.Create
                  PredefinedPackage = "Parcel",
                  Weight = 28

            Shipment shipment = await client.Shipment.Create(
                new Parameters.Shipment.Create
                    ToAddress = toAddress,
                    FromAddress = fromAddress,
                    Parcel = parcel

            await client.shipment.Buy(shipment.Id, shipment.LowestRate());

Tracking Packages

Track packages across all major carriers.

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Address Verification

Validate domestic and international addresses.

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International & Customs

Learn how to handle international shipping seamlessly.

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Shipping Insurance

Shipping insurance for all items sent with EasyPost.

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Leading companies rely on EasyPost


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Casper sped up their European launch thanks to EasyPost's support of over 30+ European carriers.

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Connect to EasyPost Today

Sign up and start shipping in the same day with our .NET Library. If you have any questions, or if you want to talk logistics, feel free to reach out to one of our shipping experts.