Try the Shopify Collection Products API

- Valid empty result pages return `200` with an empty `products` array. - Missing collections return `404` when Shopify returns not found. - Blocked pages, malformed JSON, and missing `products` roots return upstream errors. - For some storefronts, the response includes `transport_mode: "ssr_embedded"`, `total_items`, and `total_pages` (the storefront's own result-count/page-count metadata), and each product may include additive fields only available from this source: `colour`, `canonical_colour`, `discount_percentage`, `rating`, `rating_count`, `collection_tags`, `labels`, and per-variant `inventory_quantity`. `limit` is still honored as an upper bound on returned items, but the underlying page size is fixed by the storefront (commonly 60) and cannot be requested larger than that. `transport_mode`, `total_items`, and `total_pages` are omitted entirely for other stores. - When `transport_mode` is `ssr_embedded`, the response may also include `facets` and `facets_stats`, mirroring the collection page's own filter sidebar: `facets` maps a facet field name exactly as the storefront names it (for example `fit`, `activities`, `canonicalColour`, `sizeInStock`) to its value-to-count buckets, and `facets_stats` gives `min`/`max`/`avg` for numeric-range fields such as `price` and `discountPercentage`. Both are omitted when the storefront's payload did not include facet data, and always omitted for other stores. - **`sortBy` and facet filters apply to `ssr_embedded` stores only.** Rather than silently accepting and ignoring `sortBy` or a facet filter against other stores (which would look like it worked but wouldn't), this endpoint rejects the request with a `400` invalid-param error whenever `sortBy` or any facet-filter query param is supplied and the resolved store is not `transport_mode: "ssr_embedded"`. - When a sort and/or filters were applied to an `ssr_embedded` store, the response echoes back what was actually honored: `sort` (one of the enum values below) and `filters` (a map of facet field name to the array of values that were requested for it, after comma-splitting). Both are omitted when no sort/filter was supplied. - `hitsPerPage` (the storefront's own listing page size, commonly 60) is unaffected by sort/filters; `limit` continues to apply as an upper bound on the returned page. - **Storefront Filtering** (`sort_by`/`min_price`/`max_price`/`product_type`/`in_stock_only`/`option_*`) is Shopify's own native collection-page filtering/sorting feature, distinct from the `sortBy`/dynamic-facet-filter pair above. It works for all stores. When any of these params is supplied, the response has `transport_mode: "storefront_filtered"` and echoes back the effective `sort_by`, `min_price`, `max_price`, `product_type`, `in_stock_only`, and `variant_options` that were applied. `facets`/`facets_stats` are populated from the collection page's own filter sidebar when present: `facets` maps a lowercased variant option name (e.g. `size`, `color`) or `product_type` to its value-to-count buckets, and `facets_stats.price` gives the Price slider's own `min`/`max` bounds. `total_pages` is populated only when the collection page itself renders numbered pagination links; a single-page result leaves it unset. Not every Shopify store has this feature enabled — a store without it returns the unfiltered/unsorted collection page, which this endpoint cannot distinguish from "the filter matched everything" without upstream signal. `sortBy` allowed values: `sortLTH`, `sortHTL`, `newest`. `sort_by` allowed values: `manual`, `best-selling`, `title-ascending`, `title-descending`, `price-ascending`, `price-descending`, `created-ascending`, `created-descending`. `transport_mode` allowed values: `ssr_embedded`, `storefront_filtered` (omitted entirely for the classic transport).