Listings widget

Show your brokerage's listings on your own website. A brokerage admin creates the key and names the sites in Console, Website widget.

Rule	What it means
What shows	Your brokerage's homes that are Active or Pending and publicly marketed, newest change first, up to 60.
What never shows	Members only and Coming Soon homes, closed or withdrawn homes, and anything in a sandbox.
Allowed domains	Up to 10 per key: example.com, www.example.com, or .example.com for its subdomains. Naming example.com also allows www.example.com, and the other way round. Shared suffixes such as .co.uk or *.github.io are refused. https only; localhost works while building.
The key	Public by design: it sits in your page source and reads only what you already market. Revoke it in the console and every site using it stops.
Photos	Signed links that stop working as soon as a home leaves the public feed.
Each home	Links to its official listing page on ListOnce, in a new tab.
Rate limits	120 requests a minute per visitor address, 3,000 a minute per key. Over that, 429 for the rest of the minute.

Rule: What shows
What it means: Your brokerage's homes that are Active or Pending and publicly marketed, newest change first, up to 60.

Rule: What never shows
What it means: Members only and Coming Soon homes, closed or withdrawn homes, and anything in a sandbox.

Rule: Allowed domains
What it means: Up to 10 per key: example.com, www.example.com, or *.example.com for its subdomains. Naming example.com also allows www.example.com, and the other way round. Shared suffixes such as *.co.uk or *.github.io are refused. https only; localhost works while building.

Rule: The key
What it means: Public by design: it sits in your page source and reads only what you already market. Revoke it in the console and every site using it stops.

Rule: Photos
What it means: Signed links that stop working as soon as a home leaves the public feed.

Rule: Each home
What it means: Links to its official listing page on ListOnce, in a new tab.

Rule: Rate limits
What it means: 120 requests a minute per visitor address, 3,000 a minute per key. Over that, 429 for the rest of the minute.

Script

Draws a card grid that fits the width of its container, inside a shadow root so the styles of your page and ours stay apart. Put the div where the listings go; more than one div per page works.

HTML

<div data-listonce-widget="olw_xxxxxxxxxxxxxxxxxxxxxxxx"></div>
<script src="https://listonce.io/widget.js" async></script>

Iframe

For site builders that do not allow scripts. The widget sends frame-ancestors with your allowed domains, so browsers refuse to show it on any other site.

HTML

<iframe src="https://listonce.io/w/olw_xxxxxxxxxxxxxxxxxxxxxxxx" title="Our listings" loading="lazy" style="width:100%;height:760px;border:0"></iframe>

JSON

The script reads GET /api/widget/listings?key=…. It answers only browser pages on an allowed domain: CORS echoes your origin once it is on the list, and a request with neither Origin nor Referer gets 403. A script outside a browser can send any Origin it likes, so these checks stop other websites, not scrapers; the key only ever reads homes you already market publicly. For anything beyond the widget, use the API with a key of your own.

200 application/json

{
  "brokerage": "Northgate Homes Group",
  "listings": [
    {
      "key": "OL-5RB2NH",
      "status": "Active",
      "price": 512000,
      "street": "1902 Mesquite Bend",
      "city": "Phoenix",
      "state": "AZ",
      "zip": "85022",
      "beds": 3,
      "baths": 2,
      "sqft": 1760,
      "tint": 0,
      "photo": "https://listonce.io/m/OLP-XXXXXXXXXX.jpg?a=p&e=...&s=...",
      "url": "https://listonce.io/l/OL-5RB2NH"
    }
  ]
}

Status	When
403	The page is not on the key's allowed domains
404	No such key, or it was revoked
429	Over a rate limit; try again next minute

Status: 403
When: The page is not on the key's allowed domains

Status: 404
When: No such key, or it was revoked

Status: 429
When: Over a rate limit; try again next minute