> ## 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.

# PREDUPE

> Detect when a respondent has already attempted a survey while still in the supplier's environment.

PREDUPE identifies when a respondent has already attempted a survey while still in the supplier's environment, increasing platform conversion and EPC.

* **Type:** GET
* PREDUPE exists as an **add-on to the [SEARCH](https://docs.repdata.com/research-defender/guides/01-search) call** — you activate it by adding two parameters.

## Request Parameters

Add these to your SEARCH call to activate PREDUPE:

| Parameter                            | Data Type    | Description                                                                                                                                                                                                                           |
| ------------------------------------ | ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `destination_platform_id`            | GUID/UUID    | Unique identifier for the destination platform/buyer. Retrieve the full list via the [Destination Platforms](https://docs.repdata.com/research-defender/endpoints/get-api-v3-respondents-destination_platforms-private_key) endpoint. |
| `destination_platform_survey_number` | User-defined | The destination platform's internal survey number. For **Research Desk**, use the `ProjectUd` identifier.                                                                                                                             |

<Note>
  Destination platform keys for Research Defender customers are available on request. See the [SEARCH guide](https://docs.repdata.com/research-defender/guides/01-search) for definitions of `sn_ud`, `sy_nr`, and other shared parameters.
</Note>

## Example

```text theme={null}
https://prod.rtymgt.com/api/v4/respondents/search/<APIKEY>?sn_ud=[%Unique-Session-Identifier%]&sy_nr=[%Survey-Number%]&destination_platform_id=[%Platform-ID%]&destination_platform_survey_number=[%Platform-Survey-Number%]
```

Look up available destination platform identifiers:

```text theme={null}
https://prod.rtymgt.com/api/v3/respondents/destination_platforms/[PRIVATE_KEY]
```

## Interpreting the Result

PREDUPE results are returned in the SEARCH response `Surveys` array. Use `duplicate_score` (`100` = duplicate) to determine whether the respondent has already accessed the destination survey, and reroute duplicates to another opportunity.