API Connection in R

0 Votes



I am currently having difficulties in connecting to ConstantContact through API in R. Here is the code that I am currently running:


cc_app <- oauth_app("constant_contact",
key = "[redacted],
secret = "[redacted]",
redirect_uri = "https://localhost")


CCtoken <- oauth2.0_token(endpoint = oauth_endpoint(authorize = "https://authz.constantcontact.com/oauth2/default/v1/authorize", access = "https://authz.constantcontact.com/oauth2/default/v1/token"), app = cc_app)


When I run it, I am greeted with a 400 error: Your request resulted in an error. The 'redirect_uri' parameter must be a Login redirect URI in the client app settings: https://prod-ctct-admin.okta.com/admin/app/oidc_client/instance/0oa1sanwcai0kKgL30h8#tab-general.


Do I need a different redirect uri? Or is there an error within my code? My end goal is to pull campaign information and total contacts.

0 Votes

Hello OliviaSurgere,


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.


The mismatched_redirect_uri error response is  typically caused when the redirect URI in your Authorization Request doesn't exactly match the redirect URI in your key's settings (https://app.constantcontact.com/pages/dma/portal/).


One additional thing I did want to mention as well:


While it won’t return any errors if excluded from your Authorization Request, you’ll want to also include the new scope “offline_access”, which is now required for returning refresh tokens


Like so:



Here is how your initial Authorization Request URL should be formatted:


GET https:// authz.constantcontact.com/oauth2/default/v1/authorize?client_id=________________&scope=________________+offline_access&response_type=code&state=________________&redirect_uri=________________


Step 1: Create an Authorization Request



Please have a look and let us know if you have any other questions!


Courtney E.
Tier II API Support Engineer

Did I answer your question?
If so, please mark my post as an "Accepted Solution" by clicking the Accept as Solution button in the bottom right hand corner of this post.
Developer Portal

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

Visit Page


API Updates

Join our list to be notified of new features and updates to our V3 API.

Sign Up

How confident are you about the effectiveness of your current marketing strategy?

Top Choice: Not confident at all (62%)