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Arcjet · Concept

Fingerprint

Arcjet fingerprints requests with a SHA-256 string made from request characteristics. The default characteristic is the client IP address, but rules or the SDK root can use other built-in characteristics.

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Syntax

characteristics: ["ip.src", "http.host", "http.request.headers[\"<header_name>\"]"]

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  • ip.src
  • http.host
  • http.request.headers["<header_name>"]
  • rule characteristics
  • SDK root instance
  • decision cache

Source: Arcjet fingerprints. Checked 2026-11-03.