Overview

The Ad Serving API gives you full control over ad requests and responses. Use it when serving ads in email, integrating with custom UI flows, or when you need direct access to ad data.

Quick Example#

curl -G https://srv.buysellads.com/ads/CVADC53U.json \
  -d useragent=Mozilla%2F5.0... \
  -d forwardedip=198.51.100.123

The zone key CVADC53U is safe for testing.

Endpoint#

Base URL: https://srv.buysellads.com/ads/{zonekey}.json

Required parameters#

Optional parameters#

Response#

The API returns an ads array. When an ad is available, the first object contains a statlink (click URL) and creative data:

{
  "ads": [
    {
      "statlink": "//srv.buysellads.com/ads/click/x/...",
      "statimp": "//srv.buysellads.com/ads/imp/x/...",
      "description": "Squarespace is the all-in-one solution for anyone looking to create a beautiful website.",
      "company": "Squarespace",
      "callToAction": "Start a Free Trial",
      "image": "https://cdn4.buysellads.net/uu/1/45011/1558712365-squarespace_icon.png",
      "logo": "https://cdn4.buysellads.net/uu/1/45011/1558712369-squarespace_logo.png",
      "backgroundColor": "#000000",
      "textColor": "#fafafa",
      "pixel": "https://example.com/pixel?t=[timestamp]"
    },
    {}
  ]
}

When no ad is available, statlink is missing:

{
  "ads": [
    {
      "statimp": "//srv.buysellads.com/ads/imp/x/...",
      "zonekey": "CVADC53U"
    },
    {}
  ]
}

Always check for statlink before rendering. If missing, show your fallback content.

See Default Properties for the full list of available fields.

Handling Pixels#

Some campaigns include a pixel property for attribution tracking. When present, render it as invisible images:

function renderPixels(pixelString, timestamp) {
  if (!pixelString) return ''

  return pixelString
    .split('||')
    .map(
      (url) =>
        `<img src="${url.replace(
          '[timestamp]',
          timestamp
        )}" style="display:none" />`
    )
    .join('')
}

Multiple pixels are separated by ||. Always replace [timestamp] with the current time.

Concepts#

A zone represents a unit of ad inventory (e.g., "Top Sidebar", "In-content"). Each zone has a unique zone key like CVADC53U.

Zones can be grouped into placements for targeting. Most implementations need just one zone per ad location.

Verifying Your Integration#

Use browser DevTools to confirm your integration is working correctly.

Check the request#

1. Open DevTools: Network tab
2. Filter by srv.buysellads.com
3. Click the request and check Query String Parameters:

Check the response#

• statlink exists: Ad available
• statlink missing: No fill, show fallback

Common issues#

Server IP instead of client IP — Pass the client IP from X-Forwarded-For header.

Useragent not encoded — URL-encode the useragent string.

No ads returning — Verify your zone key. Use CVADC53U for testing.

Pixels not firing — Check for pixel property and render it.