Sample example of Sentiment feature of Watson NLU failing with error code 400

Question

I was trying the sample examples of various features documented at https://cloud.ibm.com/apidocs/natural-language-understanding. All the features examples are working properly except the Sentiment feature while trying with Curl.

curl -X POST \
-H "Content-Type: application/json" \
-u "apikey:{apikey}" \
-d @parameters.json \
"{url}/v1/analyze?version=2018-11-16"

parameters.json
{
  "url": "www.wsj.com/news/markets",
  "features": {
    "sentiment": {
      "targets": [
        "stocks"
      ]
    }
  }
}



Sentiment feature response:
{
  "language": "en",
  "error": "target(s) not found",
  "code": 400
}

Answer 1

Here's how it worked for me. Explaining in an elaborate way to help others.

First of all, you have to create a file named parameters.json and paste the below code

{
  "url": "www.wsj.com/news/markets",
  "features": {
    "sentiment": {
      "targets": [
        "stocks"
      ]
    }
  }
}

Pointing to the folder in which this JSON file is on a terminal or command prompt and replacing the {apikey} and {URL} with the NLU service values, run the below command

curl -X POST \                                                                                                                            
-H "Content-Type: application/json" \
-u "apikey:{APIKEY}" \
-d @parameters.json \
"{URL}/v1/analyze?version=2018-11-16"

The {URL} in my case is https://gateway.watsonplatform.net/natural-language-understanding/api

Then should see the below output

{
  "usage": {
    "text_units": 1,
    "text_characters": 1421,
    "features": 1
  },
  "sentiment": {
    "targets": [
      {
        "text": "stocks",
        "score": -0.640222,
        "mixed": "1",
        "label": "negative"
      }
    ],
    "document": {
      "score": -0.662399,
      "label": "negative"
    }
  },
  "retrieved_url": "https://www.wsj.com/news/markets",
  "language": "en"
}