Magento 2 & Hyvä, done right by one developer.

The honest minimum is 12 weeks of daily sales data per SKU — that’s enough for Prophet to lock onto a weekly pattern and produce a usable 4–6 week forecast. With 26 weeks you start getting yearly seasonality. With 52+ weeks (one full annual cycle including your peak season) Prophet really shines and you can forecast 90 days out with sub-15% MAPE on most retail SKUs. Below 12 weeks, do NOT use Prophet — fall back to a 28-day moving average plus a manual safety-stock multiplier. The model will overfit garbage if you feed it too little.

Yes — in the segments where it’s strongest. Magento (Open Source + Adobe Commerce) will dominate enterprise B2B, multi-store, regulated industries, and EU-compliance-heavy commerce through 2030 and beyond. Where it bleeds is the SMB / DTC segment under $5M GMV, which Shopify already won and now cements with Sidekick + Hydrogen. Magento survives, but its addressable market shrinks: from “everyone” to “serious B2B + custom-heavy enterprise.” That’s still a multi-billion-dollar segment globally. The platform isn’t going anywhere; the merchants who choose it just look more specific.

Both. Everything in the build runs on stock Magento 2.4.7+ Open Source — there’s no Adobe Commerce-specific API used. The observer hooks into catalog_product_save_after, which is identical on both editions. The MessageQueue layer uses Magento’s built-in MessageQueue module (also Open Source). The only Adobe Commerce-only consideration is the Image Editor extension Adobe ships, which you’d disable to avoid duplicate processing. Bottom line: Open Source merchants get the full benefit without paying for Adobe Commerce just for image handling.

MCP is an open protocol Anthropic shipped in November 2024 that lets large language models talk to external tools and data sources through a standard interface. Think of it as USB-C for AI — one socket, many devices. For Magento, MCP means Claude, ChatGPT, or Cursor can query your catalogue, check stock, summarise yesterday’s orders, or draft a discount code without you writing five different REST integrations. The protocol crossed tribal lines fast: OpenAI and Google both adopted it in early 2025, and Adobe made it the default agent protocol for Commerce at Summit 2026. That puts MCP in the same “assume it’s there” bucket as JSON-RPC or OAuth — you build for it once and every major AI client gets your Magento data for free.

No — they are different products from the same company. Hyvä Theme is a free, open-source (OSL3) Tailwind + Alpine storefront frontend for Magento, released to free in November 2025. Hyvä Commerce is a paid commercial suite of admin, media, and CMS modules that sits on top of Magento Open Source. You can run Theme without Commerce, but most stores that buy Commerce also use Theme.

Hyvä Themes is a commercial licence sold per Magento installation (not per storefront, not per developer). Pricing as of 2026:

• Hyvä Theme: €1,000 per Magento installation (one-off, perpetual). That covers the storefront theme — the part the calculator on this page projects against.
• Hyvä Checkout: €1,000 per Magento installation (one-off). Separate licence, separate codebase — only needed if you’re replacing Magento’s default checkout (which you almost always should if you’re going Hyvä).
• Hyvä Compatibility Module: free, bundled with the theme. Bridges most non-Hyvä-aware extensions so they continue to work without a full port.

That’s roughly $1,100–$2,200 USD all-in for the licences. It’s a once-off; there’s no annual renewal. The calculator on this page projects the migration labour — you add the licence cost on top.

Worth it? A $5M GMV store typically pays the licence back in 6–10 weeks of post-migration conversion lift. A $500k DTC store closer to 5–7 months.

Three reasons. (1) Holidays — Prophet has a first-class holiday regressor with country presets. ARIMA needs you to hand-encode every holiday as an exogenous variable, which gets brittle. (2) Multiple seasonalities — ecommerce demand has weekly AND yearly patterns. Prophet handles both natively; ARIMA needs SARIMA + careful order selection per SKU. (3) Defaults that work — Prophet ships with sensible priors. ARIMA needs ACF/PACF inspection per SKU, which doesn’t scale to a 5,000-SKU catalog. ARIMA is still the right pick for stable, single-seasonality B2B SKUs — just not for the typical Magento mix.