<p>Retrieves the <code>IdentityID</code> associated with a <code>DeveloperUserIdentifier</code> or the list of <code>DeveloperUserIdentifier</code> values associated with an <code>IdentityId</code> for an existing identity. Either <code>IdentityID</code> or <code>DeveloperUserIdentifier</code> must not be null. If you supply only one of these values, the other value will be searched in the database and returned as a part of the response. If you supply both, <code>DeveloperUserIdentifier</code> will be matched against <code>IdentityID</code>. If the values are verified against the database, the response returns both values and is the same as the request. Otherwise a <code>ResourceConflictException</code> is thrown.</p> <p> <code>LookupDeveloperIdentity</code> is intended for low-throughput control plane operations: for example, to enable customer service to locate an identity ID by username. If you are using it for higher-volume operations such as user authentication, your requests are likely to be throttled. <a>GetOpenIdTokenForDeveloperIdentity</a> is a better option for higher-volume operations for user authentication.</p> <p>You must use AWS Developer credentials to call this API.</p>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}