Keylight vs Cryptolens — the SDK-first alternative

Cryptolens — now rebranded Devolens — is a mature licensing API that’s been doing this for years across a long list of languages. Keylight does the same job with finished SDKs: Swift, Rust, and JavaScript, with the licensing glue and Stripe already wired in. If you’re shipping on any of those stacks, that’s the decision.

What Cryptolens gets right

Cryptolens is deep and proven. Language-agnostic SDKs — .NET, C++, Python, Java, Go, Node — with RSA-signed offline activation, node-locked and floating models, time-limited and trial licenses, and a track record at real production scale. If you sell across platforms, or your stack is .NET, or you want a licensing engine that’s been hardened over a long time, Cryptolens is a serious tool.

The Devolens rebrand leans further into that: licensing as production infrastructure for teams running complex deployments.

Where Keylight is different

Cryptolens hands you an API and SDKs in your language. What happens inside the app — storing the activation, checking expiry, the trial countdown, what to show on launch — is yours to wire. Flexible, and the right shape when you span many platforms.

Keylight ships that part. The Swift SDK is a state machine. Activate once, check on launch, switch on the result:

await licensing.checkOnLaunch()

switch licensing.state {
case .licensed: enablePaidFeatures()
case .trial(let daysLeft): showTrialBanner(daysLeft: daysLeft)
case .expired: showRenewalPrompt()
case .invalid: showActivationSheet()
}

The same backend powers Rust and JavaScript SDKs — a Tauri app, an Electron tool, or a Node service all get the same offline Ed25519 leases and the same Stripe-native minting. Payments are wired in — Stripe mints the license on payment with no webhook code, and other payment providers connect by webhook. Less to assemble, because it’s built for exactly these stacks.

When Cryptolens is the better pick

Be honest about it. If you ship across platforms where Keylight has no SDK yet — .NET, C++, Python, Java, Go — Cryptolens covers that ground well today. Its RSA-signed activation and language-agnostic model fit complex cross-platform and production licensing requirements. Need strict floating or concurrent seats at scale? That’s closer to Cryptolens’ weight class than Keylight’s today.

Keylight is Swift-first, not Swift-only — Rust and JavaScript ship too. But if your need is .NET or a long list of languages right now, Cryptolens is the straighter line.

Where Keylight fits

Building in Swift, Rust, or JavaScript and want licensing that drops in? Keylight. Finished SDKs, offline Ed25519 leases, feature flags in the lease, payments wired in, multi-product and multi-tenant built in.

The win isn’t the licensing engine — both are solid. It’s never wiring the licensing flow yourself on the stacks Keylight covers.

Plans start at $19/month, with a free tier. Drop in the SDK, connect your payment provider, ship.