Carcha Seal is a self-hostable license server and SDK set for vendors who sell installed desktop software. Instead of a proprietary binary that phones home, the app ships only a public key and verifies a short-lived, Ed25519-signed JWS lease on the device — online or offline, with a grace period. Licenses follow per-product policies: node-locked or floating/concurrent seats, perpetual or subscription, trials, and feature-based entitlements. Air-gapped machines activate and renew by exchanging a request file and a license file. Run the whole server yourself — your signing key, your database, no runtime call home — or use the hosted service with a 14-day trial. SDKs cover Electron/Node.js, .NET and C++.
