Hyvä companion module

byte8/module-vat-validator-hyva adds a live, debounced indicator under the VAT input on Hyvä registration and address forms. Calls the standard REST endpoint.

Install

composer require byte8/module-vat-validator-hyva
bin/magento module:enable Byte8_VatValidatorHyva
bin/magento setup:upgrade
bin/magento cache:flush

Where the indicator appears

Page	Field watched
customer/account/create	taxvat
customer/address/form	vat_id + country_id

Hyvä Checkout (Magewire-based) is not yet wired — open an issue if you need it.

Behaviour

• 600 ms debounce — won't spam the REST endpoint while the user types
• Recognises 2-letter prefixes (DE…, GB…) and the Swiss CHE… prefix
• Falls back to the country dropdown when no prefix is typed
• Hides itself silently on unavailable outcomes — never shows a misleading red badge when VIES is just slow

Customising

Override Byte8_VatValidatorHyva::vat-indicator.phtml in your theme. The component is a single self-contained Alpine x-data block — drop in your own copy / icons / Tailwind classes.

No extra JS dependencies

Alpine.js + Tailwind only — both already ship with Hyvä. Total JavaScript added to the page: ~1 KB inline.