Guides

Introduction

Fingerly identifies the device behind every session and scores how suspicious it is, so your application can stop fraud without adding friction for real people.

Fingerly is device intelligence for web and mobile applications. At the moments that matter, such as signing up, logging in or paying, it tells you who the visitor is and how suspicious the session looks, with every signal behind the answer.

What you get from every identification

AnswerFieldUse it to
A stable visitor IDvisitor_idRecognise a returning device across sessions, logouts and cleared storage.
How sure that isvisitor_confidenceDecide how much to trust the match, from 0 to 100.
A suspect score and levelsuspect_score, suspect_levelAllow, challenge or review, against a threshold you control.
The signals behind ittriggersSee exactly why: Tor, a VPN, automation, a rooted phone, tampering and more.
Network contextcountry_code, asn, anonymity_networkUnderstand where the session really comes from.

How an integration fits together

  1. A client SDK in your web page or app identifies the visitor with a public key and returns a request_id.
  2. Your frontend sends the request_id to your backend along with the action, such as the login form.
  3. Your backend reads the stored result with a secret key, checks it belongs to this action, and decides.
  4. Webhooks push every result to your systems as it happens, if you want them.

The score never leaves your control. Fingerly does not block anyone on its own: it gives you evidence, and your code makes the decision.

Start here

Principles

  • Outcomes, explained. Every score lists the signals and weights that produced it.
  • Your policy. Weights and thresholds are yours to tune, per organization or per key.
  • No interruptions. No SDK ever shows a permission prompt or a dialog to your visitors.
  • Free to build. Development and staging keys run the same detection as production and cost nothing.