Licensing

An app licence is your signed permission for one install or one tenant to use your app's features. You issue it from your MainSDK Cloud account; your app checks it offline against a public key you pin in main.yaml. Nothing calls home while a request runs, and the app keeps serving when nothing is reachable (ADR-0070).

import { licence } from "mainsdk";

licence.require("sso");                       // 403 unless the licence in scope includes sso
const { status, graceEndsAt } = licence.state();

licence:
  driver: http
  product: acme-desktop
  roots: ["ed25519:CvBKNOIhJSGvXg9chN9qV8-z6byK3-is6-12mXaidWQ"]   # the well-known test root: pin your own in production
  file: ./main.licence
  features: [sso, audit-export]

Four things that sound alike

They work together. A feature you sell under licence goes under licence.features; a tenant then has it only when its plan includes it and the licence does too, and a licence's seats or limits can lower a plan's limit but never raise it. A tenant licence can also name the tenant's plan. An app licence may carry a reference to a TAPS licence or asset for your own use, but licence never evaluates it and protect never reads app licences.

How a licence is checked

Each licence file holds two signed parts: the licence, signed by your issuing CA, and the CA's certificate, signed by your root. Your app pins the root's public key, so it can check the whole chain with no network. Everything is Ed25519 on the platform's WebCrypto, in a DSSE envelope over canonical JSON, so one changed byte fails.

Only licensed features turn off. The app always starts and serves, and no other protection depends on a licence.

Revocation and refresh

You revoke or suspend a licence in the Cloud, which publishes a signed revocation list. With the http driver your app fetches new lists and renewed licences in the background, never while a request waits. With the offline driver you copy a trust file in. An unreachable list never blocks a valid licence, so offline revocation is bounded by the licence's own expiry: give online installs short licences that refresh.

The app remembers the newest licence, the newest list and the latest time it has seen, so an older licence, an older list or a clock set backwards doesn't bring an expired licence back.

What it promises, honestly

A licence can't be forged or edited without your CA's private key, which never leaves the Cloud's key service, and an app that has seen something newer can't be rolled back through anything MainSDK reads. That keeps honest customers honest and makes your terms auditable.

MainSDK is open source and runs on your customer's machine. Someone who controls that machine can patch the check out or keep the machine offline. The seal reports changed files, but it can be rewritten too. Serve features worth stealing from a server you run.

Try it locally

mainsdk dev uses the local driver: with no licence file, it serves a dev licence with every feature under licence.features, signed by a test root that mainsdk check refuses in production. In tests, createTestLicenceCA() from @mainsdk/testing issues, revokes and tampers with licences. To inspect a file, run mainsdk licence show main.licence, and mainsdk licence verify in CI.

Next

• App licensing: the calls, main.yaml keys and testing kit
• License your app: the steps, start to finish
• Free in the app, paid in the Cloud
• Security model
• Check codes