> ## Documentation Index > Fetch the complete documentation index at: https://docs.airdun.com/llms.txt > Use this file to discover all available pages before exploring further. # Airdun: Automated Stripe Payment Recovery for SaaS > Airdun detects failed Stripe subscription payments, builds a recovery plan per case, and executes it across email, SMS, WhatsApp, and an in-app wall. Airdun is a recovery layer that sits on top of Stripe. When a subscription payment fails, Airdun detects the failure, builds a recovery plan for that specific case, and executes it across the channels you have enabled — until the payment succeeds or the sequence is exhausted. It is not a flow builder. You do not design sequences, write copy, or set retry timing. You connect Stripe, enable channels, and switch on the autopilot. ## Requirements * A SaaS business running subscription billing on Stripe. * A sending domain you control, if you want to use the email channel. * The Airdun snippet installed in your product, if you want to use the in-app wall. ## How it works When a payment fails in Stripe, Airdun: 1. **Creates a recovery case** — capturing the failure reason, customer history, usage signals, subscription value, and the contact channels available for that customer. 2. **Designs a strategy** — the algorithm weighs the case context (failure type, customer segment, country, timezone) to build a multi-touchpoint plan. 3. **Executes the plan** — messages go out via email, SMS, WhatsApp, and/or the in-app wall, timed to the customer's local timezone and written in their language. 4. **Stops automatically** — the moment the payment succeeds, every pending touchpoint in that case is cancelled. ## Failure types handled Each failure type resolves differently, and the strategy accounts for that: * **Card expired** — the customer must update their card before a retry can succeed. * **Insufficient funds** — retry timing matters; the schedule is anchored to likely payday windows. * **Bank block** — the issuing bank flagged the charge; customer action is usually required. * **3DS friction** — authentication was started but not completed. * **Authorization failures, limit exceeded, card declined** — each has its own resolution path and channel ordering. See [Recovery Cases](/how-it-works/recovery-cases) for the full list and what a case contains. Create your account, connect Stripe, configure your channels, and switch on the autopilot.