Device resolution

The browser SDK never asserts a device ID. Every event is resolved server-side into a device record from two independent pieces of evidence.

Two kinds of evidence

Browser instance identifier (client_hint) — an opaque random token the SDK stores in localStorage on first use. Proves "this browser's storage previously held this exact value," nothing more.
Signal similarity — the coarse browser signals collected on every event (OS family, browser engine, device class, screen dimensions, hardware hints, timezone, and a handful of others) are compared against known devices.

A confidence score, not a guess

The server computes a 0–100 confidence score from weighted signal similarity against candidate devices, then bands the result into a resolution decision (for example: resolve to an existing device, or treat this as a new device). Every resolution is traceable: which signals matched, which changed since last seen, which conflicted, and which were unknown. This is a deterministic, rule-based calculation — not a statistical or ML model, and not a claim of a specific measured accuracy rate.

Browser updates don't look like a new device

The browser's major version is tracked as history but never scored as a mismatch on its own — an ordinary browser auto-update shouldn't flip a known device into "new."

What resolution is not

A cleared browser is treated as a new device

There is no probabilistic fallback that survives a full browser reset or private/incognito mode. If storage is cleared and no other signals match closely enough, the next event is resolved as a new device — this is by design, not a gap to be filled.

No cross-browser identity linkage — Sentriq doesn't claim to recognize the same person switching from Chrome to Safari on the same machine.
No cross-device identity linkage — Sentriq doesn't claim to recognize the same person on a different physical device.
No device merge or split — two device records are never automatically (or manually) combined, and a device's history is never destructively rewritten.

What you get back

Every event response includes whether the device is new or known. With a secret key, you can pull the full resolution audit trail for any device — the matched, changed, conflicting, and unknown signals behind each decision — via the REST API.