Feature 01 — Double-Spend Prevention

You're paying for
the same conversion twice.

A pixel misfires. A user refreshes the thank-you page. A form submits twice. Google counts two conversions. Your CRM shows one lead. You optimize toward a number that was never real — and it costs you money.

See It in Action → View Live Dashboard
~15%
Estimated duplicate conversions in average ad accounts
$0
Cost to block duplicates with HashVex
100%
Duplicates cryptographically rejected — no exceptions

The problem with pixels

Every major ad platform counts conversions when a pixel fires. Pixels are JavaScript — they fire on page load, on refresh, sometimes on redirect. There's no built-in deduplication that works across sessions, devices, or browser restarts. You're trusting a client-side script to tell you the truth.

How HashVex stops it

When a conversion happens, HashVex derives a cryptographic nullifier — a unique fingerprint for that specific user and campaign. The nullifier is stored permanently in Redis and PostgreSQL. Any subsequent attempt to record that same conversion is rejected at the proof level. Not filtered. Rejected. There is no override.

What actually happens under the hood

The nullifier is generated using a Poseidon hash function — the same cryptographic primitive used in zero-knowledge proof systems like Zcash and StarkNet. It takes your user token and campaign ID as inputs and produces a deterministic, one-way output. The same inputs always produce the same nullifier. Different inputs always produce a different nullifier. Once stored, it cannot be re-used.

Nullifier (Poseidon hash output) df0a52bd2fd647b3c119fdac51d76c1f9da7235476c0c6d4e0d9609639c9d23e
Second attempt — rejected 409 Conflict: {"success":false,"reason":"duplicate","message":"Already counted"}

How it compares

MethodDeduplicationCross-sessionTamper-proof
Google Ads pixelPartialNoNo
Meta pixelPartialNoNo
Server-side GTMPartialNoNo
HashVex ZK ProofCompleteYesYes

Clean data.
Better decisions.

When your conversion count is accurate, every optimization decision downstream improves. Bid strategies, budget allocation, creative testing — all of it depends on a number you can trust. HashVex gives you that number.