Added

• Custom fields on products: define product attributes in Joomla's own Custom Fields screens (all 19 field types, validation, view levels, groups, ordering, language assignment). Values save and roll back with the product, render in a storefront Specifications tab, emit Schema.org additionalProperty on the product's JSON-LD node, index into Smart Search (value and/or facet per field), round-trip through CSV as Field: {name} columns, and read/write through the REST products API. / placeholders work in descriptions
• Custom fields at checkout: an Additional information panel collects order-level input (gift message, delivery slot, PO number) — required/pattern rules enforced server-side before the order is created
• Custom fields on addresses: address book, admin customer screen and both checkout addresses; each field can be restricted to shipping, billing, or asked on both
• Custom fields on order lines: per-item input on the product page (engraving, recipient, date), assigned to products via the field's Category assignment. Lines with different answers stay separate cart lines and draw on shared stock; identical answers merge. Editable from the cart; shown in cart, mini-cart and checkout summary
• Captured values are frozen onto the order with their labels — renaming, retyping or deleting a definition never rewrites a placed order. They appear on the order screen (editable with the same validation, timeline-logged), the customer's order detail, the confirmation and shipment emails; per-field switches gate each surface
• Related products: pick and drag-order suggestions on a product's Related tab; shown as ordinary product cards under the description. One-directional by default with an opt-in "both ways" display option resolved at read time — nothing is written to the other product, unlike HikaShop's mirror rows. Storefront visibility rules apply (unpublished / windowed / access-restricted products drop out); enabled and sized via Options → Products
• Currency switcher: new module mod_sshop_currency (dropdown or links; labelled by code, sign, name) lets shoppers read catalogue, cart and checkout in any published currency that has an exchange rate; the sidebar price filter follows. Display-only: the order, invoice, emails, reports and the gateway amount stay in the store currency — stated with the exact amount at checkout. Hides itself when only one currency qualifies
• Catalog REST API: read-only GET v1/solidshop/products|categories|brands (+ :id, products/:id/variants) with search / category / brand / price / stock filters, lang and currency args, served by the rebuilt plg_webservices_solidshop. Guest-visible data only — no cost prices, no stock quantities (boolean in_stock), no customer or order data. Public by default; a Public catalog access plugin switch gates everything behind Joomla API tokens instead
• MCP server: POST v1/solidshop/mcp exposes the catalog to AI agents as five read-only tools (solidshop_search_products, solidshop_get_product, solidshop_list_categories, solidshop_list_brands, solidshop_get_store_info) over stateless Streamable HTTP. Same shapers and visibility rules as the REST layer; every response carries the canonical storefront URL, so agent referrals land on the merchant's own pages

Changed

• Product descriptions now run through Joomla's content plugins (this is what renders ); Options → Run content plugins on product descriptions turns it off if literal {…} braces matter
• The order confirmation email gained an Additional information block and per-line custom fields under each item; the shipment email lists them per shipped item. Customised bodies are offered the change via the editor's drift banner
• Stock checks now sum every cart line of the same product instead of checking each line alone — with per-line fields one product can sit on several lines. Same correction for admin order-product edits

Fixed

• Address forms posted radio groups, checkboxes and multi-selects incorrectly — every radio in a group and every checkbox, ticked or not
• Product cards in listings emitted an empty priceCurrency in their microdata; they now carry the store's currency code

Upgrade notes

• Schema: nullable JSON custom_fields columns on #__sshop_orders / #__sshop_order_products, and the new #__sshop_product_related table (both sides cascade on delete)
• The core package gains mod_sshop_currency (installs unpublished, like every module) and plg_webservices_solidshop (enabled on install; disabling it removes all API routes)
• Currency switching is display-only by design; Joomla's System - Page Cache plugin serves one cached copy per URL to all guests, so leave it off on priced pages if you publish the switcher
• Related products are not yet in the CSV columns or the REST products API; listing pages cannot yet filter or sort by a custom field value (Smart Search facets cover narrowing inside search results)