@app blocks. The Custom Liquid section (and the Custom Liquid block on the PDP) is your escape hatch for anything that doesn’t have a dedicated block.
App block support
App blocks are Shopify’s standard way for apps to inject UI into a theme without touching code. If an app is built on the modern Theme App Extensions API, you’ll see its block appear in the Add block menu of any section that supports@app.
Sections in Voyager that accept app blocks:
To add an app block:
1
Install the app
From the Shopify App Store. Most apps that render on the PDP will tell you in their docs that they support theme app extensions.
2
Open the section
Theme Editor → product template → main-product section.
3
Add the block
Add block → scroll to the divider that separates Voyager’s native blocks from app blocks → pick the app’s block (Reviews, Loyalty widget, Bundle picker, etc.).
4
Drag into position
The new block lands at the bottom by default. Drag it where you want it to appear on the page.
Custom Liquid section
For homepage app embeds (or any one-off HTML), use the standalone Custom Liquid section. It sits in the Add section menu of the home template.1
Add the section
Home template → Add section → Custom liquid.
2
Paste the snippet
The section has one field — Custom Liquid — that accepts Liquid, HTML, inline CSS, and inline JavaScript.
3
Set the wrapper
The section’s other settings control the container width, top/bottom padding, and background scheme — useful for matching the section to the rest of the homepage rhythm.
4
Position it
Drag the section into the homepage order — typically between sections, not at the top.
Custom Liquid block (PDP)
For app code on the product page specifically, prefer the Custom Liquid block (inside the main-product section) over the standalone section. The block sits in the same column as the rest of the PDP content, so layout is automatic. Product template → Add block → Custom liquid. Drag into position.Common app categories
Recommendations below are categorical, not specific endorsements — every store has different needs.Reviews
Look for an app that exposes a theme app extension (so you can drop the block on the PDP without code). Most modern review apps do.- Star-rating snippet — a small block placed next to the product title
- Reviews widget — a larger block placed below the description
- Write a review form — typically a separate block or a customer-account page
Loyalty
Loyalty programs typically render an embed (the floating “rewards” launcher) plus optional blocks for points display and tier status.- Add the app embed via App embeds in the Theme Editor (left sidebar → Theme settings → App embeds at the bottom).
- Add per-page blocks (points balance on the customer account page, rewards widget on the PDP) where they make sense.
Bundles
Bundle apps add cross-sell, buy-X-get-Y, and “frequently bought together” widgets to the PDP.- Place the bundle block between Buy buttons and Pickup availability for “frequently bought together”
- Place a cross-sell block on the cart drawer (some apps expose a cart block)
Other categories
Add an app embed to the homepage
Some apps don’t have section blocks — they expose only a global app embed that injects an element somewhere on the page.1
Open App embeds
Theme Editor → left sidebar → Theme settings (gear icon) → scroll to App embeds at the bottom.
2
Enable the embed
Toggle the app on. Most embeds show a chevron — click it to see app-specific settings.
3
If the app has no theme extension
Fall back to the Custom Liquid section. Most apps document the exact
<script> and <div> markup you need to paste.Where to next
PDP recipes
Where to position the app blocks you just added.
Performance and accessibility
Keep Lighthouse healthy after adding apps.