API Authentication
The API Authentication is implemented as HTTP Basic Authentication over SSL (HTTPS). Your API login credentials are not the same as the credentials you use to log in to the web interface. You must obtain your API credentials separately.
Obtaining Your API Credentials
Your API key can be generated from the “API Access” tab of your seller dashboard.


Your http username is your “API Key”.
Your “password” is always the letter “x”.
Authenticating with your API Credentials
You will use HTTP Basic Authentication to verify your identity via the API. All requests must come over SSL/HTTPS, and be to the subdomain of the Site you wish to access. For example, if your Site’s subdomain is acme, then you would access the Customer resource at:
https://acme.chargify.com/customers.json
An example using authentication via curl:
curl -u api-key:x https://subdomain.chargify.com/customers.xml
or
curl -i https://<api-key>:x@subdomain.chargify.com/customers.xml
Please review the recommendations for setting your HTTP Accept and Content-Type headers as outlined in the API Introduction