The ARI extension

What is ARI?

ARI stands for ACME Renewal Information. This is an extension to the ACME protocol which allows ACME servers to communicate renewal windows for certificates to ACME clients. Before ARI, clients would decide by themselves when a certificate should be renewed according to a simple rule. This could differ greatly between clients and didn't always work well with the renewal suggestions we made to you, resulting into unnecessary reissues of certificates. With the introduction of ARI we can now provide your client with the ideal renewal windows automatically and your certificate will always be renewed at the perfect time.

Most clients support the ARI extension, to see if your client supports ARI check have a look at our client list.

How does ARI work?

When your client successfully retrieves a certificate from our ACME server it then asks our server, when should this certificate be renewed?
Our server responds with date window in which your client should start the renewal process.
Your client will check back daily to see if the window has changed. This is also beneficial in case of a revocation event, your client will immediately know it needs to renew it's certificate when this happens. Another benefit to using ARI is that you can track if your client is still actively running it's renewal tasks through our portal, because we keep track to see if your client has checked in to review it's renewal windows.

Client specific notes

Make sure to check our documentation regarding automatic renewals to verify that your client is set up to utilize ARI. Some clients, like simple-acme, require an additional step to properly utilize ARI. Always make sure you use an up to date version of your client. Some clients have only introduced support for ARI very recently, others, like cert-manager, are currently in the process of implementing ARI support.