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How the license system in my scripts works

July 16, 2026 · Dervic

The flow

1. Customer pays via PayPal
2. A license key is generated and emailed
3. The key activates on their domain

The storage

Licenses live in a SQLite table:

CREATE TABLE licenses (
  id INTEGER PRIMARY KEY,
  license_key TEXT UNIQUE,
  product TEXT,
  status TEXT,
  max_activations INTEGER
);

Verification

The script calls the API with its key and domain:

$lic = $pdo->prepare("SELECT * FROM licenses WHERE license_key = ?");
$lic->execute([$key]);

No domain match for the key? Activation is rejected. Simple, stateless, hard to abuse.

phplicensing