Commerce Bid Check API

The Commerce Bid Check API helps commerce partners make smarter routing decisions before traffic is sent.

With a single API call, partners can request a real-time Sovrn bid for a destination URL, evaluate that bid within their own routing logic, and decide whether Sovrn is the best place to send the click.

Instead of routing traffic first and measuring performance after the fact, Bid Check gives partners live bid data they can act on immediately. This helps partners understand the value of each click, compare monetization opportunities, enforce bid floors, and route traffic based on their own rules.

Bid Check is built for partners who want Sovrn to bid on the click, not automatically route the click. If you want Sovrn to manage routing and centralize performance and revenue reporting for you, Link Optimization is likely the better fit.

Who Bid Check is for

Bid Check is built for partners who manage their own routing logic or compare multiple monetization options before sending traffic, including:

• Publishers and creators with direct affiliate relationships

• BNPLs and shopping platforms comparing merchant offers

• Coupon and deal sites optimizing high-volume outbound clicks

• AI search, AI chat, and shopping assistants recommending products

• Apps and commerce experiences routing traffic across multiple networks

When to use Bid Check

Use Bid Check when you need to evaluate Sovrn’s offer before deciding where to route a click.

Bid Check is best for partners who:

• Manage their own routing logic

• Compare Sovrn against other affiliate networks or monetization paths

• Want to set minimum acceptable bid thresholds

• Need click-level control over where traffic is sent

• Want to compare CPC bids and, optionally, CPA offers in the same decision flow

• Want Sovrn to compete for clicks without taking over routing decisions

Bid Check fits into your existing redirect flow, routing system, or commerce experience. You decide when Sovrn wins and only send traffic through Sovrn when the bid meets your rules.

Key benefits

Know the value of every click

Bid Check returns a live bid for a destination URL before the click is sent. This lets partners see Sovrn’s offer in real time and decide whether to route the click through Sovrn.

Skip the EPC testing cycle

Partners no longer need to route traffic first and wait for EPC data to build over time. Bid Check replaces guesswork with live bid data, helping partners make routing decisions immediately.

Compare CPC and CPA in one decision

Bid Check can evaluate real-time CPC bids and CPA offers together when includeCpa=true, giving partners a clearer view of monetization opportunities across pricing models.

Set bid floors to protect click value

Partners can set a minimum acceptable bid using bidFloor. If Sovrn’s available bid does not meet the submitted threshold, the API returns affiliated: false.

Route on your terms

Bid Check fits into the partner’s existing redirect flow, routing system, or commerce experience. Partners decide when Sovrn wins and only send traffic through Sovrn when it meets their rules.

How the Bid Check API works

1. A user clicks a link.

2. You call the Bid Check API with the destination URL, the user’s IP address, the user’s user-agent string, and any optional tracking or consent parameters.

3. Sovrn evaluates the click and returns a real-time bid when one is available.

4. You compare Sovrn’s bid against other network offers or internal routing rules.

5. If Sovrn wins, you redirect the user’s browser to the returned Sovrn URL.

For CPC bids, the returned bid is valid for a limited time (250 ms). If the user is redirected through Sovrn before the bid expires, the returned eepc is guaranteed for that click.

eepc = estimated earnings per click

If the user is redirected after the bid expires, the click may still track and pay out, but it will use the standard link-optimization market rate rather than the quoted bid.

Endpoint

GET https://api.viglink.com/api/bid

Bid Check should be used during the click redirect flow.

Authentication

Every request must include your site’s Commerce API Key using the key query parameter.

This is the public Commerce API Key tied to the specific site, app, or traffic source sending the click. It is not the Secret Key used by other Sovrn Commerce APIs that authenticate with the Authorization header.

You can find your Commerce API Key in the Sovrn Platform under Commerce Settings > Sites. It can also be retrieved through the Campaign API.

Required parameters

The ip and userAgent values must reflect the actual end user who will be redirected through Sovrn. Do not pass the IP address or user-agent of your server. The bid is only valid for the user who is ultimately redirected.

Optional parameters

Optional tracking parameters

Use optional tracking parameters to tag clicks by user, page, campaign, placement, user segment, or content.

URL encoding

Some query parameter values must be URL-encoded before being sent.

Most HTTP clients handle encoding automatically. If you build the request URL manually, encode these values before sending the request.

Example request

curl "https://api.viglink.com/api/bid\
?key=YOUR_API_KEY\
&out=https%3A%2F%2Fexample-merchant.com\
&ip=192.0.2.1\
&userAgent=Mozilla%2F5.0...\
&bidFloor=0.01\
&includeCpa=false"

Example response: winning bid

{
  "affiliated": true,
  "pricing": "CPC",
  "eepc": 0.05725,
  "url": "https://redirect.viglink.com?u=...",
  "expireInMs": 250
}

Response fields

For CPC bids, eepc is the rate earned when the user is redirected through Sovrn before the bid expires.

For CPA offers, eepc is the average amount Sovrn expects the partner to earn per click. CPA eepc is an estimate and is not guaranteed for an individual click.

Redirecting the user

When the Bid Check API returns a winning bid, redirect the user’s browser to the returned url. This is typically done with an HTTP 302 redirect.

The redirect must happen from the real user’s browser so Sovrn receives the click from the actual user. Do not request the returned url from your server or follow the redirect server-side. Server-side redirects are not supported and will invalidate the bid.

Example response: no bid

{
  "affiliated": false
}

Sovrn returns affiliated: false when:

• There is no eligible bid

• The destination URL is not monetizable

• The available bid is below the submitted bidFloor

Status codes

Best practices

To get the most accurate bid response and avoid invalidating the bid:

• Pass the reader’s ip and userAgent, not your server’s values

• Use the Commerce API Key for the site, app, or traffic source where the click originated

• URL-encode out, userAgent, referrerUrl, and subId when building request URLs manually

• Use bidFloor when you only want Sovrn to win clicks above a minimum value

• Use includeCpa=true when you want CPA offers evaluated alongside CPC bids

• Redirect the user’s browser to the returned url immediately when Sovrn wins

• Do not follow the returned redirect URL from your server

Related resources

• Bid Check API Technical Documentation

• Link Check Technical Documentation

• Building Affiliate Links Technical Documentation

• Commerce Settings

• Campaign API

• Link Optimization vs Bid Check API: Which routing option is right for you?