Javascript net::ERR_ABORTED 400 when Getting the Access Token

0 Votes
const client_id = '{client_id}';
const client_secret = '{client_secret}';
const authBase64 = btoa(client_id+':'+client_secret);
const redirect_uri = encodeURIComponent('http://localhost/constant-contact/index.html?id=0');

const options = {
  method: 'POST',
  mode: 'no-cors',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
    Authorization: 'Basic '+authBase64

let code = findGetParameter('code');
if (!code) {
  location.href = ''+client_id+'&response_type=code&scope=contact_data&state=12345&redirect_uri='+redirect_uri;
console.log('code: '+code);
document.getElementById('authorization_code').innerText = code;

let url = ''+code+'&redirect_uri='+redirect_uri+'&grant_type=authorization_code';

response = fetch(url, options);

if (response.ok) {
  console.log('response.status: '+response.status);
  document.getElementById('response').innerText = response.json();
0 Votes

Hello XinwangN,


Thank you for reaching out to Constant Contact API Developer Support. My team is here to assist outside software developers with questions about building into Constant Contact's API.


Based on our logs for your account, it looks like you may have already resolved your issue.


However, if you still need assistance, please feel free to contact us directly/securely via email at and reference case #30215783.  


Within your email, please also include the API key that you are using to make the request, the full request(s) where you are receiving the response error (including URL, headers, timestamp, and request body), and the full response body so that we can so that we can better assist you in identifying the root cause of the issue.


Please let us know if you have any other questions!


Courtney E.
Tier II API Support Engineer

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