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Argus Fingerprinting

Argus Overview

Argus is an embeddable device-fingerprinting SDK. Identify and re-recognize visitors using unspoofable network signals fused with browser signals.

Argus is a device-fingerprinting SDK you embed in your website. Unlike Bifrost, it is not a REST API you call from your backend — you add one <script> tag and Argus identifies the visitor's device in the browser, returning a stable argus_visitor_id.

Plan requirement

Argus requires a Developer or Pro plan. Add and verify your domain in the dashboard before embedding the snippet.

How it works

Argus combines two classes of signal:

  • Server-derived (unspoofable). When the browser connects, the Argus service reads the raw TLS handshake and HTTP/2 frames to compute JA3 / JA4 and the Akamai HTTP/2 fingerprint. These are produced by the device's network stack and cannot be faked from JavaScript.
  • Client-collected. The SDK gathers high-entropy browser signals — canvas, audio, WebGL, installed fonts, speech voices, platform — and sends them to the service.

The service fuses both into a stable device identity using fuzzy matching, so the same device is recognized across visits even when individual signals drift (for example, a browser version bump or Safari private mode).

Privacy

Argus identifies devices, not people. Each fingerprint is scoped to your site-id — a visitor's identity on your site is isolated from every other site. The identity cookie (aa_fp) is a CHIPS partitioned cookie, so it is not shared across top-level sites. Document your use of Argus in your privacy policy as you would any analytics or anti-fraud tooling.

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