I see two parts to the question: 1) How are errors handled? 2) How is “incorrect” data handled?

An error response to a request indicates the entire request failed to execute. This means the input parameters supplied to the API were sufficiently bad that no sense could be made of the request. Some requests allow data to be incorrect in some way, but the incorrect data is not a sufficient reason to fail the whole request.

At the REST level, errors are reported via HTTP status codes. A message is part of the response as well. The client SDK translates the HTTP status codes into exceptions.

See: https://hosted.datascopeapi.reuters.com/RestApi.Help/Home/StatusCodes

Incorrect data such as an unknown RIC supplied as input to an on-demand extraction do not cause the whole extraction to fail. So they are not worthy of a REST API error. However, the incorrect data IS worthy of being noted in the response. The types of output vary by API endpoint used. Generally speaking, this means the API returns data that indicates some sort of warning condition.

Hello @Beera.Rajesh

You should use HistoricalSearch function to verify if a RIC is valid.

For example:

Request:

POST https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch

Authorization: Token <your_auth_token_goes_here>
Content-Type: application/json
Accept-Charset: UTF-8
Prefer: respond-async
{
  "Request": {
    "Identifier": "TRI.N",
    "IdentifierType": "Ric",
    "Range": {
      "Start": "2017-01-01T00:00:00.000Z",
      "End": "2017-05-24T00:00:00.000Z"
    }
  }
}

Response: if the RIC is valid, the field Status in the response is "Valid". The Status field

indicates the the validity of the instrument represented.

HTTP/1.1 200 OK
{
  "@odata.context": "https://hosted.datascopeapi.reuters.com/RestApi/v1/$metadata#Collection(ThomsonReuters.Dss.Api.Search.HistoricalSearchResult)",
  "value": [
    {
      "Identifier": "TRI.N",
      "IdentifierType": "Ric",
      "Source": "",
      "Key": "VjF8MHgzMDAwMDAwMDAwMDAwMDAwfDB4MzAwMDAwMDAwMDAwMDAwMHx8fHx8fHxUUkkuTnw",
      "Description": "Historical Instrument",
      "InstrumentType": "Unknown",
      "Status": "Valid",
      "DomainCode": "6",
      "FirstDate": "1996-01-02T00:00:00.000Z",
      "LastDate": "2017-05-26T00:00:00.000Z",
      "History": []
    }
  ]
}

For more details of the function, please refer to

HistoricalSearch in REST API Reference Tree

Based on my test, if the RIC is wrong, empty value is returned:

Request:

POST https://hosted.datascopeapi.reuters.com/RestApi/v1/Search/HistoricalSearch
Authorization: Token <your_auth_token_goes_here>
Content-Type: application/json
Accept-Charset: UTF-8
Prefer: respond-async
{
  "Request": {
    "Identifier": "ESM9^9",
    "IdentifierType": "Ric",
    "Range": {
      "Start": "2017-01-01T00:00:00.000Z",
      "End": "2017-05-24T00:00:00.000Z"
    }
  }
}

Response:

HTTP/1.1 200 OK

{
  "@odata.context": "https://hosted.datascopeapi.reuters.com/RestApi/v1/$metadata#Collection(ThomsonReuters.Dss.Api.Search.HistoricalSearchResult)",
  "value": []
}