USE CASE

How to charge for a browser extension

Sell a browser extension with WavePay by creating a checkout for your Pro plan, emailing a licence key on payment, and letting the extension verify an Ed25519-signed entitlement offline — T3rnel Browser sells Pro this way in production.

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Updated 2026-10-30 · by T3raTech · Free: 25 payments per 30 days, $0; Growth (recommended): 500 payments per 30 days for $49/month; Scale: 2,500 payments per 30 days for $499/month

The flow

Checkout: POST /v2/checkouts for the plan; the buyer pays with the rail they hold.
Licence: a paid checkout emails a licence key automatically.
Activation: POST /v2/licensing/activate with the key and a deviceId returns a signed entitlement.
Verification: the extension checks the entitlement offline against GET /v2/licensing/public-key — no call home on every launch.
Recovery: POST /v2/licensing/recover mails a lost key again.

Questions

Does my extension need a server to check licences?

No. Entitlements are Ed25519-signed, so the extension verifies them offline against the public key.

Who already does this?

T3rnel Browser sells its Pro tier on this exact flow.