If you receive HTML as a response of “Bad Request” instead of JSON, it is possible the POST body parameter is not valid JSON. For example, if you send this invalid JSON: 
{
    "post": "A "great" post"
    "platforms: ["twitter"]
}
A response of “Bad Request” will be returned. The code above has three issues: a missing comma on post, the post text has a double set of ” quotes without escaping, and a missing end quote on platform. The valid JSON should be: 
{
    "post": "A \"great\" post",
    "platforms": ["twitter"]
}
You can test your JSON by POSTing to the following URL to validate your JSON. Be sure to set the Content-Type to text/plain. We recommend trying the call in Postman, which can help correct JSON formatting. Please see the next section for more information.

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Validate JSON

You can validate your JSON by using either an online linter, such as https://jsonlint.com/ or using Postman. You may also use our /validate/json endpoint:

validate