banners.js is Topsort's official Web Component SDK for rendering sponsored banner ads on merchant storefronts. It handles auction requests, banner rendering, and telemetry automatically. A Topsort account and API token are required.
Directly from unpkg.com
<script>
// Must come first — analytics.js reads window.TS on load
window.TS = {
token: "<your topsort api key>",
};
// Custom behavior can be configured for each site.
window.TS_BANNERS = {
// handle the destination link
getLink(banner) {
return `https://example.com/${banner.id}`;
},
// handle loading/fetching state
getLoadingElement() {
const el = document.createElement("div");
el.innerText = "Loading...";
return el;
},
// handle errors
getErrorElement() {
const el = document.createElement("div");
el.innerText = "Error loading banner";
return el;
},
};
</script>
<script
async
type="module"
src="https://unpkg.com/@topsort/banners/dist/banners.mjs"
></script>
<script async type="module" src="https://unpkg.com/@topsort/analytics.js"></script>
<body>
<topsort-banner width="600" height="400" id="<your slot id>"></topsort-banner>
</body>For environments that don't support ES modules (e.g., Magento), use the IIFE bundle:
<script src="https://unpkg.com/@topsort/banners/dist/banners.iife.js"></script>| Bundle | Size (gzip) | Size (brotli) |
|---|---|---|
banners.mjs (ES module) |
12.40 kB | 11.01 kB |
banners.iife.js (IIFE) |
11.18 kB | 10.08 kB |
You can render multiple banners using the same slot ID and dimensions by setting up
a banner context. This is useful when you want to run an auction with multiple results.
To do that you have to pass the attribute context="true" to the topsort-banner and
use topsort-banner-slot as children elements.
<topsort-banner context="true" width="600" height="400" id="<your slot id>">
<topsort-banner-slot rank="1"></topsort-banner-slot>
<topsort-banner-slot rank="2"></topsort-banner-slot>
<topsort-banner-slot rank="3"></topsort-banner-slot>
</topsort-banner>Instead of replacing a placeholder with Topsort-generated DOM, you can annotate your own markup with data-ts-field attributes and have banners.js mutate only the targeted fields in place. All other markup — classes, ARIA attributes, styles, event listeners — is left untouched. If the auction returns no winners or fails, the predefined content is shown as-is with no changes.
Sizing is your responsibility. banners.js only fills in content fields and telemetry attributes — it never writes
width,height, or any other style to your template elements. Set dimensions with your own CSS or HTML attributes (see examples below).
Opt in by adding the predefined attribute to <topsort-banner> (standalone) or to each <topsort-banner-slot> (context mode).
Use data-ts-field to bind content keys from the auction response to element attributes or text.
Use key:target syntax to specify exactly which content key maps to which attribute:
<img data-ts-field="mainImage:src" src="/fallback.jpg" />
<a data-ts-field="target:href" href="/fallback">Click</a>
<span data-ts-field="headline:textContent">Default headline</span>Use textContent as the target to set the element's text content.
The target attribute must already exist on the element — banners.js only overwrites existing attributes, never creates them. If a binding targets an attribute that doesn't exist, it is skipped and a warning is logged. This catches typos and ensures your template always has fallback values for graceful degradation when the auction fails or returns no winners.
Comma-separate multiple key:target pairs to set several attributes on one element:
<img data-ts-field="mainImage:src, altText:alt" src="/fallback.jpg" alt="Fallback" />If the auction response only includes some keys, only matching bindings are applied — unmatched attributes keep their original values.
A bare key (without :target) infers the target from the element type:
| Element | Property set |
|---|---|
<a> |
href |
<img>, <video>, <source> |
src |
| All others | textContent |
data-ts-attr="<attributeName>" can override the default target for bare keys.
Implicit binding still works but is deprecated. Prefer explicit
key:targetsyntax for clarity and to avoid tag-based inference surprises.
Add data-ts-clickable to the element that should be the click-tracking surface for analytics.js. If omitted, the first child element is used.
<topsort-banner predefined width="600" height="400" id="slot-1">
<div class="brand-banner" data-ts-clickable>
<a data-ts-field="target:href" href="/brands/featured" aria-label="Featured Brand">
<img data-ts-field="mainImage:src, altText:alt" src="/fallbacks/featured.jpg"
alt="Explore our featured brands" width="600" height="400" loading="lazy" />
</a>
<h2 data-ts-field="default-Headline:textContent">Featured Brand</h2>
</div>
</topsort-banner><topsort-banner context width="600" height="400" id="slot-1">
<topsort-banner-slot predefined rank="1">
<div class="product-card" data-ts-clickable>
<a data-ts-field="target:href" href="/default-1">
<img data-ts-field="mainImage:src" src="/default-1.jpg" width="600" height="400" />
</a>
<h3 data-ts-field="default-Headline:textContent">Default Product 1</h3>
</div>
</topsort-banner-slot>
<topsort-banner-slot predefined rank="2">
<div class="product-card" data-ts-clickable>
<a data-ts-field="target:href" href="/default-2">
<img data-ts-field="mainImage:src" src="/default-2.jpg" width="600" height="400" />
</a>
<h3 data-ts-field="default-Headline:textContent">Default Product 2</h3>
</div>
</topsort-banner-slot>
</topsort-banner>| Name | Type | Description |
|---|---|---|
| width | Number | Banner width |
| height | Number | Banner height |
| id | String | The slot ID for this banner |
| category-id* | Optional String | The category ID of the current page |
| category-ids* | Optional String | Comma (,) separated list of category IDs, the item must match all |
| category-disjunctions* | Optional String | Comma (,) separated list of category IDs, the item must match any |
| search-query | Optional String | The search query of the current page |
| location | Optional String | The location for geotargeting |
| new-tab | Optional Boolean | Opens the banner's link in a new tab (defaults to false) |
| context | Optional Boolean | Uses the element as a context provider to render multiple banners |
| predefined | Optional Boolean | Mutates annotated child elements in place instead of replacing them |
* Only one of [category-id, category-ids, category-disjunctions] must be set.
If multiple are set, only the first will be considered, in that order.
The banner component exposes --ts-banner-width and --ts-banner-height CSS custom
properties on the <topsort-banner> element. These reflect the width and height
attributes set on the element and are useful for sizing child elements to match the
configured dimensions.
The inner container uses the class ts-banner, making it easy to target with standard
CSS selectors.
/* Style the inner container */
.ts-banner {
padding: 10px;
border-radius: 8px;
overflow: hidden;
}
/* Size child elements to match the configured banner dimensions */
.ts-banner img {
width: var(--ts-banner-width);
height: var(--ts-banner-height);
object-fit: cover;
}For responsive layouts, use standard CSS on the host element and its children rather than trying to override the custom properties:
/* Make the banner fill its container */
topsort-banner {
display: block;
width: 100%;
}
.ts-banner img {
width: 100%;
height: auto;
}| Name | Type | Description |
|---|---|---|
| rank | Number | The ranking of the slot. Ranks should be sorted the same as the winning bids. The lower the rank, the higher the bid |
| predefined | Optional Boolean | Mutates annotated child elements in place instead of replacing them |
| Function Name | Arg type | Return Type | Description |
|---|---|---|---|
getLink |
Banner | string |
Generates a URL from a banner response |
getLoadingElement |
HTMLElement |
A custom element to be shown when the banner is loading. | |
getErrorElement |
Error | HTMLElement |
A custom element to be shown when the banner errors. |
getNoWinnersElement |
HTMLElement |
A custom element to be shown when the auction returns no banner. | |
getBannerElement |
Banner | HTMLElement |
A custom clement to be shown when a banner is loaded. |
| Name | Type | Description |
|---|---|---|
type |
"product" | "vendor" | "brand" | "url" |
The type of the winning entity, represented by the banner. |
slotId |
string |
The ID of the winning entity. If the entity is of type URL, this is the URL. |
resolvedBidId |
string |
The corresponding auction ID of the winning entity. |
asset |
[{ url: string; content?: Record<string, string> }] |
An array of assets. content is a key-value map used in predefined content mode. |
If you want to use your own user identification system instead of the automatic opaque user ID, you can override the getUserId function in the window.TS configuration.
Your custom getUserId function should return the user's ID as a string. You are responsible for generating and persisting the ID (e.g., in a cookie or local storage).
window.TS = {
token: "<your topsort api key>",
getUserId() {
// Return your custom user ID
// This will be used for both auction requests and event reporting
return globalUserId ?? generateAndStoreUserId();
},
};This configuration needs to be set before analytics.js is loaded or imported.
The banner component emits an event when the state changes. You can listen to this event to write custom logic.
The various states are loading, ready, error, and nowinners.
document.querySelector('#my-slot-id').addEventListener('statechange', (event) => {
console.log(event.detail); // { status: 'ready', banner: { ... } }
});Try the library instantly — no setup required — at the live demo:
Enter your API token and a slot ID to render a real banner and copy the resulting HTML snippet.
git clone https://github.com/Topsort/banners.js.git
cd banners.js
pnpm install
pnpm run devYou can find your API token and slot IDs at app.topsort.com.