VIES

Use case

A business customer in another EU country buys without VAT (reverse charge) — but only once its VAT number is confirmed. Osysharp.Shop asks whoever its ShopSetup.VatNumbers names; this kit answers from the European Commission's VIES register, which every member state's VAT numbers are checked against. It returns whether the number is valid, and the registered name and address where the member state publishes them.

Install and use

app MyShop {
  use Osysharp.Shop@1 { … }
  use Osysharp.Shop.Vies@0 { egress "ec.europa.eu"; }
  …
}

using Osysharp.Shop.Vies;

app.Shop = new ShopSetup { …, VatNumbers = new ViesCheck() };

Staff then make an account wholesale with its VAT number checked, and the shop prices that account's orders without VAT where the rules say so. A VIES answer that is not a success is refused with the register's status, never taken as "valid"; a member state that withholds the name and address is answered with both empty.

Source and package

• Source: model/Vies.osy (ViesCheck : IVatNumberCheck).
• Tests: tests/vies.test.osy, with every call to VIES stubbed.
• Package: use Osysharp.Shop.Vies@0; — osy lock fetches the release archive from this repository's releases.

Get it

Add the kit to your app’s manifest:

app MyApp {
  use Osysharp.Shop.Vies@0 {
    egress "ec.europa.eu";
  }
}

Then run osy lock: it downloads the release, verifies it by its content address and pins that version in osyrin.lock. osy kits Osysharp.Shop.Vies shows what the kit is for, from inside your app.