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

# Update Session Data

> Patch extracted KYC or Proof-of-Address data on a session — corrections, manual overrides, redactions.

Use this when an OCR field is wrong, a name needs normalisation, or a compliance officer is correcting transcribed data.

## Request

```bash theme={null}
curl -X PATCH https://identity.contra.id/v1/sessions/$SID/data \
  -H "x-api-key: $CONTRA_KEY" -H "Content-Type: application/json" \
  -d '{
    "first_name":     "Mikayla",
    "last_name":      "Halvorson",
    "date_of_birth":  "1966-10-02",
    "country":        "GB",
    "document_number":"AB123456"
  }'
```

All fields are optional; send only what changes.

## Response · 200

```json theme={null}
{
  "session_id": "sess_b3f1c2a4",
  "data_updated": true,
  "audit_entry":  "rev_a8f2…"
}
```

<Warning>
  Updating session data is **audited and on-chain anchored** in the next hourly batch. The original Smile/Didit-extracted values are preserved alongside the override.
</Warning>