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

# Research Defender Predupe

> Use Research Defender's /PREDUPE check to detect respondents who already attempted a survey through another source.

Panel overlap constitutes a huge loss of traffic — at times over 10% of all transactions. As more respondents appear on multiple panels, exchanges, marketplaces, and aggregators see reduced conversions. The ability to track duplicative respondents *before* a survey attempt is a key lever in preventing this issue.

`/PREDUPE` helps address this by leveraging APIs to signal whether a respondent has previously attempted a survey from a different panel or source.

## Product Summary

* `/PREDUPE` exists as an add-on to the `/SEARCH` API call. It lets a supplier check whether a respondent has already attempted to take the destination survey.
* If `/PREDUPE` detects that the respondent has already taken the survey through another supplier, `"flag": 1` will appear on the API response.
* `/SEARCH` checks against duplications in the survey provided by the `sy_nr` parameter, while `/PREDUPE` checks against duplications in the survey provided by the `destination_platform_survey_number` parameter.

## Parameters

| Parameter                            | Description                                                                                                                                                                            |
| ------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Defender API Key                     | Specific to Research Defender — **not** the same as your Research Desk Supply API key. If you don't have one, inquire at [supply@repdata.com](mailto:supply@repdata.com).              |
| `sn_ud`                              | The session ID from your platform.                                                                                                                                                     |
| `sy_nr`                              | The survey number from your platform (not Research Desk).                                                                                                                              |
| `destination_platform_id`            | Research Desk's destination platform ID: `31476a3e-9262-4888-aaeb-d9325eefcafe`.                                                                                                       |
| `destination_platform_survey_number` | The `ProjectUd` shown on the parent Survey object for the Stream you are sending to (retrieved from the [Surveys endpoint](https://docs.repdata.com/supply/endpoints/get-v2-surveys)). |

## Example API Call

```text theme={null}
https://prod.rtymgt.com/api/v4/respondents/search/<YOUR DEFENDER API KEY>?sn_ud=<sn_ud>&sy_nr=<sy_nr>&rt_cy_ce=us&destination_platform_id=31476a3e-9262-4888-aaeb-d9325eefcafe&destination_platform_survey_number=<ProjectUd>
```

Research Defender response:

```json theme={null}
{
  "Respondent": {
    "respondent_ud": "50b75f77-06ef-4a1b-9083-84cf7ef2e946",
    "respondent_risk": 0,
    "country_code": "US",
    "country": "United States",
    "threat_potential_score": 1,
    "threat_potential": "low"
  },
  "Surveys": [
    {
      "duplicate_score": 0,
      "destination": {},
      "duplicate_initial_ud": "",
      "failure_reason": "",
      "country_mismatch": 0,
      "duplicate_potential": "low",
      "survey_number": "20210575",
      "flag": 1
    }
  ]
}
```

<Tip>
  If `"flag": 1` appears on the `/PREDUPE` response, the respondent has already accessed this Project. We recommend rerouting the respondent to another opportunity.
</Tip>