Biometric Deduplication

Detect duplicate identities by comparing a user's biometric data (face encoding) against all previously enrolled users. Prevents multi-account fraud by identifying if the same person has registered under different identities.

Privacy Notice

Biometric data is processed in accordance with data protection regulations. Face encodings are stored as irreversible mathematical vectors — original images cannot be reconstructed.

POST/biometrics/dedup/check

Check a face image against the biometric database for potential duplicates.

Request Body

Parameter	Type	Description
`userId`required	string	Your internal user identifier
`selfieBase64`required	string	Base64-encoded selfie image (JPEG or PNG)
`selfieMimeType`	string	Image MIME type (default: image/jpeg)
`threshold`	number	Match similarity threshold 0.0–1.0 (default: 0.90)
`enroll`	boolean	Enroll this face into the database if no match found (default: true)

Code Examples

curl -X POST https://api.verifyhq.com/v1/biometrics/dedup/check \
  -H "X-API-Key: your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "userId": "user_123",
    "selfieBase64": "/9j/4AAQSkZJRg...",
    "threshold": 0.90,
    "enroll": true
  }'

Response (No Match)

200 OKjson

{
  "id": "dedup_abc123",
  "userId": "user_123",
  "status": "UNIQUE",
  "matchFound": false,
  "enrolled": true,
  "checkedAt": "2026-02-18T13:00:01Z"
}

Response (Match Found)

200 OKjson

{
  "id": "dedup_def456",
  "userId": "user_456",
  "status": "DUPLICATE",
  "matchFound": true,
  "enrolled": false,
  "matches": [
    {
      "matchedUserId": "user_789",
      "similarity": 0.97,
      "enrolledAt": "2026-01-10T08:00:00Z"
    }
  ],
  "checkedAt": "2026-02-18T13:00:01Z"
}

GET/biometrics/dedup/:id

Retrieve the result of a biometric deduplication check.

curl https://api.verifyhq.com/v1/biometrics/dedup/dedup_abc123 \
  -H "X-API-Key: your_api_key"

Check Statuses

Parameter	Type	Description
`UNIQUE`	status	No matching face found in the database — identity is unique
`DUPLICATE`	status	One or more matching faces found — potential multi-account fraud
`PROCESSING`	status	Face encoding and comparison in progress
`ERROR`	status	Face could not be detected in the image

Webhook Events

Parameter	Type	Description
`dedup.unique`	event	Biometric check confirmed unique identity
`dedup.match`	event	Duplicate biometric match detected