Create subscriptions and configure dunning in Recurly

Steps

1. Authenticate by including your Recurly private API key in the 'Authorization' header as 'Basic {base64(api_key:)}'; generate API keys in Recurly Admin Console > Integrations > API Credentials.
2. Base URL is https://v3.recurly.com; all requests must include 'Accept: application/vnd.recurly.v2021-02-25' (or current version date) and 'Content-Type: application/json' headers.
3. Create an account first by POSTing to /accounts with 'code' (your unique identifier for the customer), 'email', 'first_name', and 'last_name'; the account must exist before creating a subscription.
4. Create a subscription by POSTing to /subscriptions with 'plan_code' (referencing a plan configured in Recurly), 'account' object (with 'code' referencing the account), and 'currency'; include 'billing_info' with payment method details or a token from Recurly.js.
5. Configure dunning in Recurly Admin Console > Settings > Dunning Management — define retry schedules per payment method type (credit card, ACH, PayPal); dunning configuration is UI-based and does not require API calls for the schedule itself.
6. Monitor failed payments and dunning status via webhooks; configure endpoint URLs in Admin Console > Integrations > Webhooks for events like 'failed_payment_notification' and 'subscription_expired_notification'.