Caylem, a Next.js SaaS boilerplate sold as working source
People call it a SaaS boilerplate, a starter kit or a template. Caylem is the web application you are using now, sold as editable source: sign-in, checkout, a backend, a source library and reusable pages, already connected. You start from a working product and build the part that is specific to yours.
By Caylem · Reviewed
What a SaaS boilerplate gives you
A SaaS boilerplate is the code that nearly every web product needs before its first useful feature: accounts, payments, a database, email, a design system and a way to deploy. Buying one moves that setup out of your first weeks, so you can spend them on the problem your customers pay for.
Boilerplates differ in how much of that is connected. Some provide separate features for you to assemble. Others ship as a running product. The useful question is how much of the journey from visitor to paying customer already works.
What is in the Caylem boilerplate
Caylem is a Bun and Turborepo monorepo in strict TypeScript. It contains two Next.js storefronts that share one Convex backend and database, Clerk sign-in, Polar checkout, Resend with React Email templates, and shadcn/ui components with reusable page layouts.
It also includes a separate prototype app with no sign-in, database or payments, so you can try a focused interface before you connect services. GitHub Actions workflows cover checks, releases and deployment to Cloudflare Workers. Repository instructions and agent skills give developers and coding agents a map of the architecture.
A working application, not a feature list
The pages, sign-in, catalog, checkout, purchased-source library and code browser on this site are the product you receive. You can use the complete purchase journey before you buy, then read how it works in the source.
That journey is built to sell digital products: one-time purchases of an exact release and an updates subscription. If your product needs plans, seats, teams or usage billing, you build those rules on the existing foundation.
What you still build
A boilerplate cannot supply your product. Your data model, workflows, permissions and customer-facing features are still your work. You also configure your own Clerk, Convex, Polar, Resend and Cloudflare accounts, and pay their fees.
Caylem does not include enterprise single sign-on, tenant isolation, audit trails or compliance certification. Use it as a foundation for a focused product, a client project or an internal experiment, and plan the remaining work.
Source you keep under MIT
Each purchase includes the source ZIP for the release shown at checkout, under the MIT license. You can modify it, ship it under your own brand and use it for client work, provided you keep the required notices.
Later releases do not update your project automatically. Buy another release when you want it, or subscribe to get the latest and earlier snapshots while your subscription is active.
Common questions
Is Caylem a SaaS boilerplate or a template?
Both words describe it. Caylem is a complete, running Next.js application that you receive as source and adapt. It is closer to a working starter than to a visual template.
Can I use Caylem for client projects?
Yes. The MIT license permits commercial use and client work. Keep the notices, and give each client project its own repository and service accounts.
Do I have to use Clerk, Convex and Polar?
The connected storefronts use them. The included prototype app runs without any of them. You can replace a service, but that is your own development work.
Where can I sell with the included payments?
Polar publishes its supported payout countries and reviews each seller account. Check your country and product against its rules before you rely on it.
Inspect the application you would build on
Review the current release, changelog and USD price. A purchase includes that source ZIP under MIT. Your service accounts, product development and maintenance are separate. Future releases do not update your project automatically.
See source & USD price