CartRules is the newest thing I’m building: a spin-off of Business Bloomer focused entirely on one niche: WooCommerce… cart rules (you saw it coming!).
Being brand new, every decision about how it runs is still being made from scratch, including how the premium plugins get delivered and get sold. For CartRules One in Cart PRO, and every plugin that follows it, I needed a stack that solved both.
This post is the case study behind that decision: why API & License Manager for WooCommerce and Constellation WooCommerce Memberships & Subscriptions, both built by Kestrel, turned out to be the combination that worked, and not by accident 🙂
If you’re selling WooCommerce plugins and wrestling with the same two problems, the rest of this post walks through exactly how to set it up.
Subscriptions, updates, and licences
A one-time purchase gets you a sale, and not much else. The customer pays $49, downloads the plugin, and that’s the whole relationship unless they email support.
There’s no built-in mechanism to charge them again next year, so renewal revenue depends entirely on someone remembering to come back and buy again.
Updates have the same gap. Once a plugin is sold, the customer expects new versions to keep working, security fixes to land, and compatibility to hold up as WooCommerce itself moves forward.
None of that maintenance work gets paid for twice unless there’s a subscription tied to it.
What API & License Manager Solves
With Kestrel’s API & License Manager running the licensing side of the business, every purchase of CartRules One in Cart PRO generates a license key, tied to the order and the customer’s site.
That key is what the plugin checks against on activation, and it’s what powers the update feed, so the customer’s WordPress install sees new versions the same way it would for a plugin hosted on WordPress.org.
License issuing, activation limits, remote deactivation when a license moves to a new site, all of it worked well from day one. What API & License Manager doesn’t do on its own is… ARR (annual recurring revenue)! It manages the key, not the billing.
Hello Constellation
Constellation is Kestrel’s membership and subscriptions plugin, and the detail that mattered most to me is who builds it. Kestrel also builds API & License Manager, and both plugins trace back to the same codebase.
That’s not a coincidence I stumbled into. It’s the reason I looked at Constellation first instead of shopping around.
Stitching together two plugins from unrelated developers to cover licensing and billing means guessing how one should react when the other changes state.
Does a lapsed subscription know to revoke a license? Does a manually issued license know it’s supposed to expire? With both plugins coming from the same vendor, those questions already have answers built in, because Kestrel wrote both halves with the other one in mind.
How the Two Plugins Divide the Work
Once Constellation is active, the split is straightforward.
API & License Manager keeps doing exactly what it says on the tin: issuing the license key, handling activation and deactivation, and serving updates.
Constellation owns everything about the money: the recurring charge, the renewal date, what happens on a failed payment, and what happens when a customer cancels.
The connection between them is the product itself. A subscription product in Constellation generates recurring orders the same way a normal WooCommerce order gets created, and API & License Manager reacts to those orders exactly as it would to a one-time purchase. When a subscription renews, the license stays active. When a subscription lapses or gets cancelled, the license lapses with it. Neither plugin needed custom code to make that happen. It’s just how a subscription order and a license-issuing plugin normally interact in WooCommerce.
Setting It Up
The setup is a lot less involved than I expected going in.
Install and activate Constellation. Plugins → Add New → Upload Plugin, upload the zip, activate. Constellation requires WooCommerce, which was already active, so there was nothing else to configure before it lit up.
Convert the product to a subscription. On the One in Cart PRO product page, changing the product type from Simple to Subscription (the type Constellation adds to WooCommerce) exposes the recurring price and billing interval fields in place of the regular price field. For this product, that’s $49 per year, the same price customers were already paying, just billed annually going forward instead of once.
Leave API & License Manager alone. This is the part that surprised me most. Nothing about the license key setup needed to change. It still watches the same order-completed events it always did, so the moment a subscription order comes through, whether it’s the first one or a renewal, the license logic fires the same way.
Going Forward
One in Cart PRO is the first premium CartRules plugin; every plugin that ships under the CartRules brand from here on gets built with this stack in mind from the start, rather than bolted on after the fact.
If you’re building a WooCommerce plugin business and you’ve hit the same wall, one-time sales that work but leave updates and renewals unfunded, this is the combination I’d point you to first. Same vendor, same assumptions, and a lot less guessing about how the pieces fit together.
Leave a Reply