Curated Product Roundup
A reader is on a curated article — “Best Headphones Under $200”, “Holiday Gift Guide”, “10 Kitchen Gadgets We Love”. The article features several products, each with a Buy Now button. The reader can add multiple items to one cart across the article and check out once.
This is the multi-product Publisher Commerce shape. Roundups drive higher average order value because the editorial framing already does the cross-sell work — readers arrive in browsing mode and convert on multiple items.
Recommended setup
| Choice | Default | Why |
|---|---|---|
| Integration pattern | Embedded Buy Button | Same buttons as Shoppable Article, with cart accumulation across multiple Buy Now clicks in the article |
| Auth | Browser session | Per-reader article session |
| Payment | Google Pay, PayPal Express, Card via JWE, Klarna BNPL | Higher cart values warrant offering BNPL |
| Attribution | UTM + publisher identifier + article identifier + per-line-item product identifier | Publisher knows which items in the roundup drove orders |
API sequence
The flow follows the Multi-Product Purchase shape — multiple POST /cart/line-items calls as the reader clicks Buy on different products in the article.
| Step | Endpoint |
|---|---|
| 1. Bootstrap session | POST /api/v1/browser-session |
| 2. Add to cart (per click) | POST /cart/line-items |
| 3. Read cart for review | GET /cart |
| 4. Set shipping address | POST /cart/shipping-info |
| 5. Pick shipping method | POST /cart/shipment/methods |
| 6. (Optional) Get delivery availability | POST /cart/shipments/get-availability |
| 7. (If required) Get + set merchant consents | GET /cart/consents → PUT /cart/consents |
| 8. Get payment public key | GET /payment/key |
| 9. Complete order | POST /payment/complete-order |
The valid shipping_method_ids for step 5 come from the cart itself — cart.shipments[].shipping_method_options, populated by step 4 (set-shipping-info). get-availability (step 6) is optional and returns delivery dates, time slots, or pickup locations for scheduled-delivery or in-store-pickup shipments — not shipping methods. Steps 2–7 build the cart, so step 9 finalizes it with complete-order (body: encrypted_card + billing_info); use place-order only for the one-shot create-cart-and-order call.
Considerations the article surface owns
- Cart accumulation across multiple Buy Now clicks. Make sure the cart session persists across each Add — don’t bootstrap a new session per click.
- Visible cart count. A persistent cart badge (top of article, sticky on scroll) shows “3 items added” so the reader knows they’ve been building a cart.
- Cart panel before checkout. Opening the cart panel surfaces all items with adjust/remove controls. The reader can drop items before paying.
- Single-merchant constraint. All items in a Publisher Commerce roundup cart must come from the same source merchant. If the roundup features products from different merchants, each Buy Now click is a separate cart (or you need Marketplace instead).
- Affiliate attribution per line. The publisher’s commission may differ per product or category. Attribution metadata flows per line item so reconciliation is accurate.
Related
- Multi-Product Purchase Flow — full API walkthrough
- Embedded Buy Button pattern
- Shoppable Article — single-product variant
- Marketplace — for an operator aggregating many merchants in one surface