Open-Source Calendly Alternative in 2026: Cal.diy After Cal.com Closed

When we self-host a tool for a client, what matters is which fork is maintained and actually open, not which brand launched loudest. I am Manoj, at MithTech, a team of Frappe specialists in Bengaluru; our small, senior team of 35 uses AI throughout delivery, and we self-host scheduling, CRM and ERP for clients across India.

This space got messier in 2026. "Open source" moved under the project's feet, so picking the right codebase matters more than the feature list.

What happened to Cal.com's open-source status?

Cal.com moved its production code to a private repository in April 2026, after about five years as an open-source project. Its stated reason was security: AI tools now find and exploit flaws in public code faster than teams can patch them. Cal.com's own write-up dates the change to mid-April 2026.

The public repository became Cal.diy. So Cal.com the company went closed, while the open-source code continues under a new name and a more permissive licence.

What is Cal.diy?

Cal.diy is the community edition of the old public codebase, published by Cal.com under the MIT licence (the code had been AGPL-3.0). It needs no licence key and has no enterprise directory mixed in.

It keeps the original stack: Next.js, React and TypeScript, PostgreSQL with Prisma, tRPC and Tailwind, with Docker deployment supported. That matters if you plan to extend it, because the codebase is familiar to most web teams.

The second option is the last AGPL-3.0 Cal.com release published before the switch. It has the fuller feature set, but it is a frozen snapshot: treat it as a fork you maintain yourself, not a living upstream.

What does Cal.diy keep, and what did it drop?

Cal.diy does one job: a public booking page. Availability rules, automatic time-zone detection, calendar sync, confirmation emails and video-meeting links are all there, which covers what most consultants and freelancers need from a Calendly replacement.

The features Cal.com treats as commercial moved to the closed product:

Cal.com presents Cal.diy as an option for individuals and self-hosters rather than as a recommended production platform. If you need round-robin team scheduling, routing and automated reminders as self-hosted open source, the path is the frozen AGPL-3.0 release, with the upkeep that a frozen codebase brings.

How do you self-host Cal.diy?

Plan an evening, not five minutes. The stack is standard; the slow part is that each calendar and video provider needs its own OAuth app that you create and own.

How does Cal.diy compare to Calendly and closed Cal.com?

Cal.diy competes with Calendly on ownership and licence, not on managed convenience. Calendly is proprietary SaaS billed per seat, with a free tier; you never touch the code or the servers.

Managed-edition prices change often; check each vendor's pricing page rather than a figure in a blog post.

Who should self-host, and who should not?

Self-host when data ownership, no per-seat billing or deep customisation matter more than convenience, and when someone can run a Node and PostgreSQL app. Independent consultants, agencies embedding booking into their own product, and privacy-minded businesses fit Cal.diy.

Stay on managed SaaS if scheduling is peripheral and your team is non-technical. A booking page is not where most small businesses should spend their engineering evenings.

If you already run open-source infrastructure, a self-hosted scheduler is a small extra step, and that is the pattern we see most: teams that already self-host their ERP, CRM or support desk fold scheduling into the same stack. The directory of open-source SaaS alternatives covers the categories around it.

If you want this open source Calendly alternative on a server you control without running it yourself, under managed hosting we run one named server for it, in your cloud account or ours: nightly backups copied off the server, one restored on a schedule, every upgrade tried on a copy first, and the master login stays yours. It is a monthly fee for running it plus the server, quoted in writing after a call. The self-hosting cost comparator sets that against doing it yourself and against a per-seat Calendly bill.

Where does scheduling fit alongside your ERP?

A booking usually needs to become a lead, a project task or an invoice somewhere. Because you own the scheduler's data and server, wiring bookings into the rest of an open-source stack is plumbing, not a vendor negotiation.

For many Indian businesses the anchor of that stack is ERPNext, which is open source under the GPL-3.0 licence and runs on the Frappe framework. A booking captured in Cal.diy can arrive in ERPNext as a lead through a webhook, keeping sales, projects and accounting in one system; the ERPNext CRM guide covers the lead side.

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