Pre-checkout blocks
To enable Fast Checkout, you’ll add a Cartsaver block to your theme using Theme App Extensions. No code editing — everything happens inside Shopify’s theme customizer.
Supported pages
Section titled “Supported pages”Three pages can host the block:
- Product page — appears just below the “Add to cart” button.
- Cart page — appears just above the “Checkout” button.
- Sticky / announcement bar — a slim bar across all pages for non-logged-in shoppers.
Adding the block
Section titled “Adding the block”- From Shopify admin: Online Store → Themes.
- On the current theme, click Customize.
- Use the top dropdown to pick a page (e.g. “Product page”).
- Click Add block and choose Cartsaver Fast Checkout under the Apps section.
- Drag it to the position you want on the page.
- Configure the block settings on the right (see below).
- Click Save in the top bar.
Block settings
Section titled “Block settings”| Setting | Description |
|---|---|
| Heading | Text shown above the input field. |
| Button color | Match your store theme or use the Cartsaver palette. |
| Button size | Default, large, or full-width. |
| Name field | Show or hide. Default: shown. |
| Privacy message | Small caption below the button reassuring the customer about their number. |
Requirements
Section titled “Requirements”- Your theme must support App Embeds (every Online Store 2.0 theme does).
- The Fast Checkout main switch is enabled in Cartsaver → Settings → Fast Checkout.
- OTP channels are configured (see OTP channels).
Temporarily disabling
Section titled “Temporarily disabling”To turn off the block without removing it from the theme:
- In Shopify’s theme customizer, hide the block with the eye icon.
- Or in Cartsaver, turn off the Fast Checkout main switch.
Plan limits
Section titled “Plan limits”- Free and Advanced: 10 Fast Checkout orders per month.
- Unlimited and Scale: unlimited.
Once the limit is reached, the block stays visible but skips OTP and shows the customer a “Continue without verification” message.
Verify it works
Section titled “Verify it works”- In Settings → Fast Checkout, the main switch shows Enabled.
- Open your store in a normal browser tab — the block appears on the pages where you added it.
- Enter your own phone number — a verification code arrives on your chosen channel, and once you confirm it, you reach the checkout page directly.