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Unlock Launches Support for Fiat NFT Recurring Subscriptions

Users can now subscribe to NFTs using fiat payment options such as credit cards.

By searchableguy on

Fiat subscription confirmation page

We recently launched support for crypto based NFT subscriptions which allowed people to pre-approve an amount in erc20 to be charged at a regular interval set in the membership contract.

Today, we are extending the same support to fiat payment options we provide (including credit card, Apple and Google Pay). Creators can now add recurringPayments: number to the paywallConfig when building their checkout URL in order to charge their users on a regular frequency.

A really interesting tidbit is that even users who pay with their cards are receiving a subscription NFT that gets renewed every time their card is charged!

Here is an example of paywallConfig.

{
  "title": "Recurring membership demo",
  "locks": {
    "0xf1e4861bbe6aa736084ff829507145a85f4958fc": {
      "name": "Recurring",
      "network": 5,
      "recurringPayments": 12
    }
  }
}

Learn more about how to build and configure the url on the docs site.

How does it work?

Unlock's approach to recurring fiat payment has two distinct elements:

Smart Contracts

We added support for grantKeyExtension method on our contracts which allows creators and anyone who is a keyGranter to extend the NFT duration. This is available in all locks starting with v11. We use this internally to renew memberships of users who have subscribed via fiat payment options.

Locksmith

When a user goes through a recurring purchase, we create a subscription object on the backend to keep track of how many times the user wishes to renew it and store all the details surrounding the purchase. Due to the volatile nature of many crypto-currencies, fiat prices can swing drastically between two payments. To avoid this and protect the users, we lock in the fiat price at the time of subscription for further renewals. This means if the user purchased an NFT for 0.1 tokens valued at $10 at the time of purchase, further renewals would only cost that $10, even if the price of the token is now much higher or much lower. We use the subscription object to renew keys when they expire.

An example of a lock with 5 minute renewal time below getting extended every 5 minutes.

Etherscan

Documentation

Further resources