> ## Documentation Index
> Fetch the complete documentation index at: https://docs.jelou.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Human in the Loop (HIL)

> Human review for biometric cases the agent cannot resolve with certainty.

Human in the Loop (HIL) adds a human operator to the biometric process: it reviews cases where the agent doesn't have enough certainty to approve or reject automatically, before the verification is resolved.

<Info>
  HIL is available **only for Enterprise accounts**. It is not a standard product feature.
</Info>

## How to activate it

You cannot activate HIL from Brain Studio: **manage the activation through your assigned Account Manager**, who coordinates enablement with the product team.

## What an HIL operator does

Human operators assigned by your company get access to a review platform where they can **approve or reject** cases the biometric agent flags as uncertain, stating the reason, or **reject and send to blacklist** immediately when the case warrants it.

### Coordinated fraud detection

HIL identifies when the same document is linked to multiple phone numbers, with an automatic risk level:

* **High:** three or more clients linked to the same document.
* **Medium:** two clients linked.

The relationship is displayed in a network graph.

### Blacklist management

* Bulk block or removal of up to one hundred users in a single action.
* Support for temporary blocks with a scheduled duration.
* Historical log filterable by company, date, status, and operator.

### Traceability and roles

HIL records every case with who reviewed it, when, and under what criteria. You manage access by role (admin / operator), with segmentation by company and/or country.

<Info>
  HIL can increase the approval rate by **five to fifteen percent** compared to pure automatic rejection, by resolving ambiguous cases that would otherwise be rejected.
</Info>

## When is a request sent to HIL?

HIL receives a case when the biometric agent detects a signal of doubt that is not enough to reject the process outright.

### By document verification level

In WebView, the main trigger is an error in any parameter set as **required** for the document verification level you configure on the Biometrics node. See the [document verification level](/en/guides/integraciones/identidad/webview-biometrics) to review and adjust these parameters.

| Level        | Required parameters that route to HIL                                                                                                   |
| ------------ | --------------------------------------------------------------------------------------------------------------------------------------- |
| **Standard** | Document type and origin, expiry date, and physical security elements.                                                                  |
| **Advanced** | Everything in Standard, plus the document's overall result and, when enabled, the automatic reading zone and document data consistency. |
| **Custom**   | Depends entirely on the parameters you set as required for your company. Any required parameter that errors out routes the case to HIL. |

### Other signals that trigger HIL

These signals route a case to human review regardless of the document verification level configured:

* Too many document retries with HIL active (maximum three attempts; liveness has a separate retry limit).
* Screenshot detection — the selfie comes from a screen instead of a live capture.
* Document tampering detection — a substituted photo or modified data.

<Tip>
  Only parameters marked as **required** trigger an HIL derivation when they fail. Review this configuration on the Biometrics node before enabling HIL to avoid derivations you don't expect.
</Tip>

<Warning>
  The system always rejects some cases outright, without going through HIL: failed liveness, facematch below the threshold, underage users, a document that doesn't match the accepted type, or a failed government validation.
</Warning>

## What HIL does not cover

* Deduplication or identification of synthetic or recycled biometric identities via a 1:N search against the client's full facial database.
* System-level role permission controls (read/write by profile) — currently under evaluation.