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Fingerprint allows you to filter requests to prevent bad actors from making identification requests using your account. Filtered-out requests do not count toward your Fingerprint billing. However, if you use Cloudflare Proxy Integration, those requests can still be proxied through your Cloudflare worker, which can increase your Cloudflare costs. To prevent this, you can block specific IPs or origins at the Cloudflare worker level by using Cloudflare’s Web Application Firewall.
Cloudflare Web Application Firewall
  • You are limited to 5 WAF custom rules on the Cloudflare free plan.
  • This guide uses the Cloudflare dashboard to create WAF custom rules manually. You can also create and modify custom rules programmatically using the Cloudflare API.

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1. Find the worker route

The JavaScript agent v4 uses a single worker route for all requests to Fingerprint servers. The easiest way to find your route is from the JavaScript agent configuration snippet on SDKs & integrations > Cloudflare:
  1. Go to SDKs & integrations > Cloudflare in the Fingerprint dashboard.
  2. Find the JavaScript agent configuration snippet.
  3. Copy the WORKER_PATH part from the endpoints value.
For example, if your snippet uses https://yourwebsite.com/icXhT6JSJ2MhAdk6/?region=us, then your worker route to protect is /icXhT6JSJ2MhAdk6*.

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2. Create a firewall rule

Create a custom rule in your Cloudflare WAF.
  1. In the Cloudflare dashboard, go to Websites > Your website > Security > WAF > Custom rules.
  2. Click Create rule.
  3. Enter a name for the rule.
  4. Use the visual editor or click Edit expression to define the rule using the Rules language.
  5. Choose Block as the rule action.
  6. Click Deploy.
Screenshot of the firewall rule

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Block requests from specific IP addresses

For example, to block IPs 111.111.112.113, 114.112.222.33, and the entire 211.12.82.0/24 subnet for worker route /icXhT6JSJ2MhAdk6*, use this expression: 
(
  ip.src in {111.111.112.113, 114.112.222.33, 211.12.82.0/24}
  and starts_with(http.request.uri.path, "/icXhT6JSJ2MhAdk6")
)

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Block requests from specific origin and referer

For example, to block requests from example1.com for the same worker route, use this expression: 
(
  starts_with(http.request.uri.path, "/icXhT6JSJ2MhAdk6")
  and
  (
    any(http.request.headers["origin"][*] == "https://example1.com")
    or
    any(http.request.headers["referer"][*] contains "https://example1.com/")
  )
)
Block requests by referer in addition to origin because some request types do not include the origin header. See the Cloudflare rules language documentation for more details.

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Cloudflare limitations