Shield Quickstart

Shield is a deterministic, weighted rule engine (IP intelligence, velocity, card BIN risk, device fingerprinting, blocklist, sanctions screening) that scores every live transaction for fraud risk from 0 to 100. This guide walks you through enabling it and setting your thresholds.

1. Enable Shield and set your thresholds

In Shield → Settings, or via PUT /shield/settings:

curl -X PUT https://api.wajub.com/shield/settings \
-H "Authorization: sk.xxxx" \
-d '{
  "enabled": true,
  "review_threshold": 50,
  "block_threshold": 80,
  "auto_3ds_enabled": true,
  "blocklist_enabled": true
}'

Scores between review_threshold and block_threshold are held for manual review; scores at or above block_threshold are blocked automatically. Start with a high block_threshold (e.g. 90) and a lower review_threshold (e.g. 50) to catch obvious fraud without over-blocking legitimate customers, then tighten over time.

2. Read the score on each payment

The shield block is included in the payment response.

{
"shield": {
  "score": 18,
  "band": "low",
  "decision": "allow"
}
}

3. A blocked payment

A block decision rejects the payment outright.

{
"status": "Forbidden",
"message": "Payment blocked by Shield",
"code": 403,
"shield": { "score": 91, "band": "critical", "decision": "block" }
}