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

# NFC Issuer

> NFC issuer endpoints, including migration for World ID v3 NFC credentials.

The NFC issuer exposes endpoints for issuing and migrating NFC credentials. For product-level credential semantics, Sybil-resistance guarantees, and validity details, see [NFC Credential](/world-id/credentials/9303).

<Note>
  The base URL is environment-specific. Contact your World ID point of contact for
  environment endpoints and access.
</Note>

## Migration

<Warning>
  This endpoint is intended for World ID v3 holders to obtain v4 NFC
  credentials. It is not a general re-issuance endpoint for v4 holders.
</Warning>

<ParamField path="method" type="POST">
  /v2/migrate
</ParamField>

**Content-Type:** `application/json`

### Request

#### Headers

<table>
  <thead>
    <tr>
      <th className="whitespace-nowrap">Header</th>
      <th>Required</th>
      <th>Description</th>
    </tr>
  </thead>

  <tbody>
    <tr>
      <td className="whitespace-nowrap">
        <code>x-zkp-proof</code>

        <br />

        <code>string</code>
      </td>

      <td>yes</td>
      <td>Base64-encoded JSON containing the ZKP proof and identity commitment.</td>
    </tr>

    <tr>
      <td className="whitespace-nowrap">
        <code>attestation-gateway-token</code>

        <br />

        <code>string</code>
      </td>

      <td>yes</td>
      <td>Attestation gateway token for device integrity verification.</td>
    </tr>
  </tbody>
</table>

#### Body fields

<table>
  <thead>
    <tr>
      <th className="whitespace-nowrap">Field</th>
      <th>Required</th>
      <th>Description</th>
    </tr>
  </thead>

  <tbody>
    <tr>
      <td className="whitespace-nowrap">
        <code>identityCommitment</code>

        <br />

        <code>string</code>
      </td>

      <td>yes</td>

      <td>
        The holder's identity commitment (decimal or hex with <code>0x</code>{" "}
        prefix). Must match the ZKP header.
      </td>
    </tr>

    <tr>
      <td className="whitespace-nowrap">
        <code>sub</code>

        <br />

        <code>string</code>
      </td>

      <td>yes</td>

      <td>
        World ID 4.0 blinded subject identifier (hex with <code>0x</code>{" "}
        prefix, 256-bit). Must match previous migrations for this identity.
      </td>
    </tr>

    <tr>
      <td className="whitespace-nowrap">
        <code>credential</code>

        <br />

        <code>object</code>
      </td>

      <td>yes</td>

      <td>
        Flow-specific credential data (see below). The client decrypts PCP data
        locally before submission.
      </td>
    </tr>
  </tbody>
</table>

#### Credential fields

<Tabs>
  <Tab title="Passport / eID">
    The `credential` object contains data extracted and decrypted from the user's Personal Custody Package (PCP) by the client.

    <table>
      <thead>
        <tr>
          <th className="whitespace-nowrap">Field</th>
          <th>Description</th>
        </tr>
      </thead>

      <tbody>
        <tr>
          <td className="whitespace-nowrap">
            <code>credential.sod</code>

            <br />

            <code>string</code>
          </td>

          <td>
            Base64-encoded SOD (Security Object Document) in DER format from
            the identity document.
          </td>
        </tr>

        <tr>
          <td className="whitespace-nowrap">
            <code>credential.verification\_metadata</code>

            <br />

            <code>string</code>
          </td>

          <td>
            Base64-encoded verification metadata from the original document
            check.
          </td>
        </tr>
      </tbody>
    </table>

    ```json theme={null}
    {
      "identityCommitment": "0x000000000000000000000000000000000000000000000000000000000000000c",
      "sub": "0x000000000000000000000000000000000000000000000000000000000000002a",
      "credential": {
        "sod": "<base64-sod-der>",
        "verification_metadata": "<base64-json>"
      }
    }
    ```
  </Tab>

  <Tab title="MNC (My Number Card)">
    <table>
      <thead>
        <tr>
          <th className="whitespace-nowrap">Field</th>
          <th>Description</th>
        </tr>
      </thead>

      <tbody>
        <tr>
          <td className="whitespace-nowrap">
            <code>credential.sd\_jwt</code>

            <br />

            <code>string</code>
          </td>

          <td>SD-JWT (Selective Disclosure JWT) from the MNC verification flow.</td>
        </tr>
      </tbody>
    </table>

    ```json theme={null}
    {
      "identityCommitment": "0x000000000000000000000000000000000000000000000000000000000000000c",
      "sub": "0x000000000000000000000000000000000000000000000000000000000000002a",
      "credential": {
        "sd_jwt": "<sd-jwt-string>"
      }
    }
    ```
  </Tab>
</Tabs>

### Response

#### Success response

```json theme={null}
{
  "result": {
    "credential": "<base64-encoded World ID v4 credential>"
  }
}
```

#### Error responses

| Status | Error              | Description                                                                 |
| ------ | ------------------ | --------------------------------------------------------------------------- |
| 400    | `invalid_data`     | Request payload is malformed or missing required fields.                    |
| 400    | `sub_mismatch`     | `sub` does not match the one used in previous migrations for this identity. |
| 400    | `document_expired` | The identity document has expired and cannot be used for migration.         |
| 401    | `unauthorized`     | Authentication failed.                                                      |
| 404    | `not_found`        | No matching enrollment record found for this credential.                    |

## Planned Endpoints

### Enrollment <Badge disabled icon="lock" color="blue">Coming soon</Badge>

Details coming soon.

### Re-issuance <Badge disabled icon="lock" color="blue">Coming soon</Badge>

Details coming soon.

## Implementation Notes

<Note>
  This is advanced documentation about the internal workings of the NFC
  Credential and is not relevant for RP integration.
</Note>

### Associated Data

The associated data of this credential contains different data groups found in the original document. More information coming soon.

#### Associated Data Commitment

To ensure the associated data has guaranteed integrity and can be re-used in the future for credential re-issuance, the commitment is computed as follows:

1. For ICAO-9303 documents, the message digest of the `EF.SOD` signature is used. The message digest is obtained from `SignedData.SignerInfos[0].SignedAttrs` where the signed attribute for the digest is identified by the Object Identifier `1.2.840.113549.1.9.4`. This digest is then hashed with the `blake3` hashing function from the raw bytes. Finally, the `blake3` hash is converted to a field element with modulo reduction.
2. Information on MNC documents coming soon.