Cartwright Plus — buying and activating

How the Plus purchase works end-to-end — checkout, your access key, activation in your shop, billing portal, and key reissue via support.

Cartwright Plus is a membership, not a license. The engine is MIT and stays MIT — Plus adds priority support, upgrade guidance, the Pro agent playbooks, and SEO/GEO Lab beta access on top. This page walks through the whole loop: buy → key → activate → manage billing → reissue.

1. Buy

The pricing page checks out through a Stripe Payment Link ($49/mo, cancel anytime). There is no Cartwright account system: Stripe is the system of record, and billing self-service happens through Stripe's customer portal (email + one-time code login).

2. Your Plus access key

Right after checkout you land on /plus/success, which shows your Plus access key — a string that looks like this:

cw_plus_v1.eyJ2IjoxLCJwbGFuIjoicGx1cyIs...  (one long line)

The same key arrives by email. Treat it like a password: it is your proof of membership. Technically it is an Ed25519-signed statement of your subscription — your self-hosted shop can check its authenticity fully offline, and cartwright.app can additionally confirm the live subscription status. It contains no name, no email, no payment data.

3. Activate

Two ways, either works:

Admin UI — open /admin/plus in your shop's admin and paste the key. (This page arrives with engine v0.40; until then use the env var below.)
Environment variable — set CARTWRIGHT_PLUS_KEY=<your key> on your deployment (Vercel project settings, Docker env, .env.local) and redeploy.

4. Billing and cancellation

Invoices, card changes, and cancellation all live in the Stripe customer portal — the link is on your success page and in your activation email. Cancel anytime, effective at the end of the billing period.

5. Lost your key?

Email support from the address you purchased with and we reissue it — manually, usually same day. There is deliberately no automated recovery form yet; at current volume a human is faster and safer.

What happens if verification fails?

Honest answer: very little, by design. Cartwright's enforcement is trust-based — the key gates support, private artifacts, and future Plus updates, and it never shuts down your site. Concretely:

If cartwright.app is unreachable, your shop honors a previously verified key for seven days and shows "offline grace".
If the subscription is canceled, you lose access to support, private downloads, and future Plus updates — nothing already in your repository is touched.
Your storefront, checkout, and every line of MIT code you already have keep running, always. Cancellation never disables an existing site.

We would rather you stay for the support than because of a kill switch.

Key rotation (operator note)

Access keys carry a key id (kid) naming the keypair that signed them, and verification selects the matching public key by that kid. When cartwright.app rotates its signing keypair, the retired public key stays in the verifier's keyring (CARTWRIGHT_PLUS_PUBLIC_KEYS, a JSON map of kid → public key), so keys issued before a rotation keep working — you never need to re-activate after a rotation on our side. Only if a key is actually compromised would its kid be dropped, and affected members get a fresh key by email.