Sending tokens to Actions On Google returns error "Can't parse the response. The response needs to be JSON format"

Question

Good morning, I am using ASP.NET HTTP API as Actions on Google fullfilment. I have an error message when I try to send tokens to Actions on Google project. Regarding to another question I read I made sure to have clear int value (not decimal) and it doesn't work.

My JSON which I send to Actions on Google:

{"token_type":"Bearer","access_token":"edeaa27e-12b7-43a1-bc7c-e6bbf9af71c3","refresh_token":"4344383b-cf07-4d12-a5c2-44b6481f5f48","expires_in":86400}

Error message:

{
    insertId: "1o7lj2bmu"
    jsonPayload: {
        @type: "type.googleapis.com/google.identity.accountlinking.type.AccountLinkingError"
        errorReason: "Can't parse the response. The response needs to be JSON format."
        response: {
            body: ""{\"token_type\":\"Bearer\",\"access_token\":\"edeaa27e-12b7-43a1-bc7c-e6bbf9af71c3\",\"refresh_token\":\"4344383b-cf07-4d12-a5c2-44b6481f5f48\",\"expires_in\":86400}""
            status: 200
    }
    step: "AUTH_CODE_EXCHANGE"
    }
    logName: "projects/smartlightproject-f47f4/logs/accountlinking-pa.googleapis.com%2Ferror"
    receiveTimestamp: "2022-07-12T12:32:40.739532642Z"
    resource: {2}
    severity: "ERROR"
    timestamp: "2022-07-12T12:32:40.539Z"
}

What's wrong with that JSON? Or maybe I should do it in some other way? I will be very very grateful if you could help me with that.

Here's my code after some improvements:

var result_acceess_token = "edeaa27e-12b7-43a1-bc7c-e6bbf9af71c3";
var result_refresh_token = "4344383b-cf07-4d12-a5c2-44b6481f5f48";
var expires_expires_in = 86400;

var resultObj = new
{
     token_type = "Bearer",
     access_token = result_acceess_token,
     refresh_token = result_refresh_token,
     expires_in = expires_expires_in
};

return Ok(resultObj);

Earlier I tried to serialize JSON with JsonConvert and return it as JsonResult or raw string value.

Answer 1

It looks like the response you're sending back is the JSON as a quoted string. That is - there is a quote at the beginning and end of the JSON. While this is a valid JSON string (it is, after all, a quoted string), it sounds like it is looking for a JSON object.

Verify the body of the response and make sure it does not contain the opening and closing quotes.