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Custom Subdomain

What Is Custom Subdomain Integration?​

Using a custom subdomain lets you serve the fingerprinting script and API through your own domain. This keeps the agent in a first-party context, improving accuracy, bypassing ad-blockers, and ensuring compatibility with strict browser privacy features.

Key Benefits​

  • Higher accuracy & longer cookies: Extends cookie lifetimes on browsers where third-party storage is heavily restricted.

  • Ad-blocker evasion: Common ad blocking rules won't block the script from executing.

How It Works​

You set up two DNS records for your selected subdomain pointing to our service. We validate domain ownership, automatically provision SSL, and start routing traffic through it.

Important Naming Guidelines​

  • Pick a subdomain without ad-related words (e.g., avoid 'ads', 'analytics', 'stats', 'tracking', 'metrics').
  • Avoid using 'overpoweredjs' or 'opjs' in the name.
  • The subdomain should be dedicated to the fingerprinting traffic.

Integration Steps​

1. Choose and Enter Your Subdomain​

In your dashboard:

  • Navigate to Integrations > Add Subdomain
  • Enter the desired subdomain, e.g., mysubdomain.example.com.

Note: Once registered, subdomains cannot be edited.

2. Update Your DNS Records​

At your DNS provider (Namecheap, GoDaddy, etc.), create the following records:

TypeSubdomainTarget/Value
CNAME_acme-challenge.mysubdomain.example.com(Target address provided in dashboard)
CNAMEmysubdomain.example.comcustom-domain.overpoweredjs.com
  • First CNAME record validates ownership and allows automatic SSL issuance.
  • Second CNAME record routes fingerprinting traffic directly to our infrastructure.

Script loading​

<script src="https://mysubdomain.example.com/opjs.min.js"></script>

Invoke the API​

opjs({ API_KEY: 'my-api-key', ENDPOINT: 'https://mysubdomain.example.com/fingerprint' }).then(fp => {
  console.log(fp);
});

If you're using Cloudflare, implementing the Cloudflare Integration is advised.