> ## Documentation Index > Fetch the complete documentation index at: https://rogus-docs.frimty.com/llms.txt > Use this file to discover all available pages before exploring further. # Introduction > Rogus turns your Shopify catalog into a product feed for Google Merchant Center and other shopping channels. What it does and how it works. **Rogus** turns your Shopify catalog into a **product feed** — the file that shopping channels read to list your products. It starts with **Google Merchant Center**, and can also build a feed in any shape you define. Rogus runs inside your Shopify admin. It reads your products and never changes them, and it does not touch your theme or storefront. ## The idea in one paragraph Google will not read your Shopify store directly. It wants a file listing your products in its own format, with its own field names. Rogus builds that file for you: you say once where each Google field comes from in your catalog, and Rogus produces the file and keeps it up to date. You give Google the address of the file, or connect your Google account and let Rogus send the products across for you. ## How it works Pick what kind of feed you want, give it a name, and choose the country and language you sell to. The country decides the currency your prices publish in. For a Google feed, Rogus fills in the obvious mappings already — product title to `title`, price to `price`, and so on. You review them and fill in anything Rogus cannot guess, such as your product category. Rogus reads your catalog and builds the file. Products missing something Google requires are listed for you and left out of the file — the rest still publishes. Copy the feed URL into Google Merchant Center, or connect your Google account and let Rogus send the products directly. After that, Rogus keeps the feed current. On a paid plan it notices catalog changes and rebuilds the feed on its own. ## Core concepts | Concept | What it means | | ---------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Feed** | One export of your catalog, for one channel and one country and language. It has its own settings, its own field mapping, and its own URL. | | **Item** | One row in the feed. **Each product variant becomes its own item.** Variants of the same product are linked, so Google shows them as one listing with options rather than as separate products. | | **Attribute** | A field in Google's product data specification — `id`, `title`, `description`, `link`, `image_link`, `availability`, `price`, and the rest. | | **Mapping** | The rule that says where an attribute's value comes from: a product or variant field, a metafield, or a fixed value you type in — with an optional fallback. | | **Skipped item** | A variant left out of the feed because something Google requires had no value. Skipped items are listed for you to fix. They never break the rest of the feed. | | **Template** | The shape of the feed: **Google Shopping**, or a blank **XML** or **CSV** file whose fields you name yourself. Chosen when you create the feed and fixed after that. | ## What you can build Google's attributes, pre-mapped and checked against their specification. The feed publishes as XML. Your own fields, with your own names, in your own order. For a channel that wants XML in its own shape. The same, as a spreadsheet file. For a channel or tool that reads CSV. ## What Rogus can see Rogus asks for three read permissions and no write permissions: * **Products** — titles, descriptions, images, prices, variants, barcodes, tags, categories * **Inventory** — stock levels, so `availability` is correct * **Metaobjects** — only so that a metafield you map can point at one It cannot edit your products, and it never receives your orders or your customers' details. ## Where to go next Get your first feed into Merchant Center. Limits, prices, and what happens at the cap.