Second accounts
from the same person

Nolgard ties a signup to earlier ones through the browser, the device and the normalized email, so your backend knows before it hands out another full credit balance.

Decision trace

How it works

1. Send an account

   Include your opaque account id and, optionally, email when verifying a signup.

2. Count the links

   Per-site hashes connect browser visitor ids, fingerprints and normalized emails.

3. Review the cluster

   See linked accounts. Label Fraud or Legit; your backend applies the returned grant.

API

Query linked account ids from your backend. Keep the secret server-side.

POST https://nolgard.com/v1/cluster
Content-Type: application/json

{
  "secret": "SITE_SECRET",
  "accountId": "user_123"
}

// Example response
{
  "size": 3,
  "accounts": ["user_123", "user_456", "user_789"]
}

Limits

• Default repeat threshold: three. The fourth distinct device-linked account triggers repeat_device. Device and email links cover 30 days.
• Network counts cover 24 hours. Ten accounts trigger repeat_network, but an IP prefix never joins accounts into a cluster.
• Clusters use the newest 20,000 eligible links per site within 30 days. Older links can be omitted at high volume.
• A shared device is evidence, and an office or a family shares one too. A Legit device label clears repeat limits for 30 days.
• A fresh device, browser and email can evade these links. The first account is never a repeat account; other risk signals may still apply.
• Observe mode returns allow plus wouldDecide and wouldGrant. Start there before enforcing.

Related

• Email intelligence
• Trial grants
• Usage abuse