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.
It looks like we've already followed up with you directly via email, but here is the information provided for visibility on the forum: Based on the information provided it appears that you're requesting information for our V3 API which generates the API Key and Secret but doesn't give you an Access Token right away as we use OAuth 2.0 for verification instead. When it comes to our V3 API we don't also don't utilize Mashery. If you need an API Access Token for our V3 API below are links to steps on how to obtain the Access Token along with Access Token Information.
V3 API: Retrieve the Access Token https://developer.constantcontact.com/api_guide/client_flow.html#step-3-retrieve-the-access-token Access Token Information Method https://developer.constantcontact.com/api_guide/token_info_method.html
Also, just in case this is what you needed instead, here are steps on how to obtain the Access Token for our V2 API. V2 API: How to generate an API Key and Access Token: https://community.constantcontact.com/t5/Community-News/How-to-generate-an-API-Key-and-Access-Token/ba-p/293856
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