Setting up authentication token retrieval in Postman API

Occasional Contributor

Setting up authentication token retrieval in Postman API

Has anyone had luck setting up token retrieval in Postman API?


I can get the token when going through the folder authorization steps, but not when trying to create POST/GET requests. Using the "Get New Access Token" method in the folder authorization, I am required to login every time. This is not sustainable.


For anyone with experience with this, I am attempting to follow the steps here.

1. In Postman, I create a GET request. GET


client_id: {{clientid}} (same as in the Get New Access Token process)

redirect_uri: https://localhost (same is in the Get New Access Token process)

response_type: code

scope: contact_data+campaign_data


2. This returns an HTML form that does not seem to work in Postman.


3. I am expecting to get an authorization code, but I do not see where this comes from. 


4. Attempting to send a POST request to the



Authorization: Basic (base64 {{clientid}}:{{API Secret}})

Content-Type: application/x-www-form-urlencoded


Response is:

    "error_description": "unable to parse Authorization header No credentials provided with BasicAuthorization",
    "error": "invalid_client"



Re: Setting up authentication token retrieval in Postman API

Hello @NCJTC,


Thank you for reaching out to Constant Contact's API Support.


Step 1 from the server flow will end up redirecting you to the URL that is in your redirect_uri which is a website. If you used http://localhost then it will be a blank website that will have a generic error message; however the URL will have the authorization code appended. I've included a screenshot of what you will see below. The reason this does not work in POSTman is because POSTman does not display websites (at least I have not been able to get them to display).


postman url.png

Jimmy D.
Tier II API Support Engineer
Developer Portal

View API documentation, code samples, get your API key.