Liveness
When the user is present in an identity journey, Liveness is the first capability to run.
What it does
Detects whether the captured selfie comes from a real person in front of the camera, and not from a photograph, video, mask, or any other injection attempt. It works alongside the SDK or Unico's Web journey to guide the user until a biometrically valid frame is obtained.
Inputs
Capture is handled by the SDK or the Web journey — you do not send an image manually to Liveness. The input is the session opened via POST /v1/process with a flow that includes Liveness.
To use Liveness in headless API integration, the implementation of one of the Unico SDKs (Web, Android, iOS, or Flutter) is required — Liveness cannot be invoked via API alone with a base64 image.
Possible responses
| Response | Meaning |
|---|---|
YES | User is alive. |
NO | Liveness attempt failed. |
Availability
| Surface | Supported |
|---|---|
| SDK (Android, iOS, Flutter) | ✅ |
| Web (iFrame, Redirect) | ✅ |
| API (headless, no SDK) | ⚠️ Requires Unico SDK for capture |
Valid combinations
Liveness is part of nearly every flow in the catalog:
idlive, id, idlivetrust, idtrust, idcheck, idchecktrust, iddocs, idsign, iddocssign, idchecktrustdocs, idchecktrustsign, idchecktrustdocssign, idtrustdocs, idtrustsign, idtrustdocssign, idunicodocs, idunicosign, idunicodocssign, idunicoserprodocssign, idcheckserpro, idcheckserprodocs, idcheckserprodocssign, creditoconsignado, idtoken, idtokentrust, idtokensign.
For the full matrix, see Available flows.
idsmart (Smart Revalidation) — replaces active capture with metadata/passkey validation plus previously captured biometrics.