Cal.diy: open-source community edition of cal.com

Posted by petecooper 5 hours ago

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Comments

Comment by FlamingMoe 4 hours ago

From the docs, "It is strictly recommended for personal, non-production use."

Wow what a 180 from just a year ago when their blog said, "For companies that handle sensitive information, deploying open-source scheduling software on-premises can offer an extra layer of security. Unlike cloud services controlled by external vendors, on-prem installations let teams maintain full ownership of their infrastructure. " ¹

I just cannot trust a company that does a bait and switch like this.

¹ https://cal.com/blog/open-source-scheduling-empower-your-tea...

Comment by Ethee 4 hours ago

I think this is less a bait and switch and more just a legal liability shield. They're not saying you 'cant' use it that way. They just don't recommend you do, and they won't support you at all for doing so. Which I think is completely fair. Also, these two things aren't in contradiction. Deploying on prem does offer more security, but then it's up to you to use it correctly.

Comment by loa_in_ 3 hours ago

It being open source also allows you to actually have a read of the software and guarantee things yourself, which is the harder better path anyway.

Comment by tecoholic 2 hours ago

This actually makes me wonder if cal.com has had a security breach in their hosted offering that they are not disclosing.

Comment by sqircles 2 hours ago

It seems to be more that they're using "security" as a reason for going closed source, so this is just sticking with the story.

Comment by tecoholic 6 minutes ago

Fair point.

Comment by sreekanth850 3 hours ago

I still remember when they launched here. "Opensource Alternate to Calendly" was their post title.

Comment by fnoef 3 hours ago

What do you want, it’s hard to resist VC money and “the enterprise offering”

Comment by theturtletalks 1 hour ago

Not impossible though, I run a directory of open-source alternatives and rarely do you see what Cal.com did. Projects gets abandoned yes, but a pure bait and switch like this really grinds my gears. This is from someone who is self hosting Cal.com right now and now they are going to strip even more features.

Comment by spiderfarmer 2 hours ago

That's why I'm worried about Laravel taking on a huge sum.

Comment by hrimfaxi 4 hours ago

[dead]

Comment by _ache_ 2 hours ago

I just installed calrs, a recent alternative to cal.diy. It absolutely rocks! The only downside is that it requires me to activate STARTTLS as force-TLS-SMTP isn't supported (I had to check the source code). It’s young, very promising, and honestly, I don't know what I could ask for more.

I also replaced Radical with rustical, and I gained free push updates.

https://cal.rs/ and https://github.com/lennart-k/rustical

And if you wanna try it out. https://cal.ache.one/u/ache

Comment by preya2k 1 hour ago

Seems to be mostly vibe coded.

Comment by hocuspocus 56 minutes ago

It is vibe-coded by people from Vates, the company maintaining https://github.com/xcp-ng

Their internal IT infrastructure runs self-hosted OSS wherever possible. I don't think cal.rs is a toy project, they know the perils and headaches of doing open source.

Comment by _ache_ 1 hour ago

Yes, sadly. :(

Comment by conradev 2 hours ago

Tempted to buy cal.zone or cal.sucks just to add the paid features to cal.diy. They even made a list!

  Teams, Organizations, Insights, Workflows, SSO/SAML, and other EE-only features have been removed
cal.ws is $630 on Namecheap... the tokens required to build this are cheaper than the domain.

Comment by singiamtel 1 hour ago

I'm surprised cal.zone is not taken already

Comment by j1elo 2 hours ago

Here is a simple trick: do accept plenty of open source contributions as-is, without any kind of copyright assignment nor requiring to sign anything that grants power to relicense.

There you go, guaranteed community ownership of the code, best face and "good will" as promised by choosing a FOSS license to begin with, and future rug pulls averted.

Seeing it from the other side of the fence: if you see that all contributors are required to cede controlling power into a single hand (except certain Foundations, yadda yadda), it's not proper Open Source in spirit, only in form; and closeups are just a change of mind away.

Comment by raphaelcosta 4 hours ago

It’s curious what they said in the email they sent me about the OSS version.

------

A few important changes to note:

We will no longer provide public Docker images, so your team will need to build the image yourselves.

Please do not use Cal.diy — it’s not intended for enterprise use.

Comment by OsrsNeedsf2P 3 hours ago

Wait, I didn't even realize Cal.diy is owned by Cal.com. It seems like they're trying to get ahead of the open source community forking by doing this themselves

Comment by dabeeeenster 2 hours ago

How curious. Are they trying to throw security shade on running open source? Very odd.

Comment by lrvick 2 hours ago

As a former cal.com advocate, I am now going to be switching my two companies to cal.diy or a similar alternative and canceling my cal.com subscriptions.

I am now actively rooting for cal.com to go out of business now as a cautionary tale for any company thinking about taking open source projects proprietary.

FOSS || GTFO

Comment by pnw_throwaway 1 hour ago

You might want to double-check the cal.diy maintainer before your wish is granted..

Comment by bluehatbrit 4 hours ago

Cal.com has always had an open source community edition, I've been using it for some time. Is this just a rebrand of that line?

Comment by geoffschmidt 4 hours ago

https://cal.com/blog/cal-com-goes-closed-source-why

Comment by rectang 3 hours ago

I'm unpersuaded by the assertion that closing the source is an effective security bulwark.

From that page:

> Today, AI can be pointed at an open source codebase and systematically scan it for vulnerabilities.

Yeah, and AI can also be pointed at closed source as soon as that source leaks. The threat has increased for both open and closed source in roughly the same amount.

In fact, open source benefits from white hat scanning for vulnerabilities, while closed source does not. So when there's a vuln in open source, there will likely be a shorter window between when it is known by attackers and when authors are alerted.

Comment by goodmythical 2 hours ago

The HN discussion on the announcement is just 90% posts of the theme "if a student can brute force your FOSS for $100, they can do you proprietary code for $200" and "if it's that cheap to find exploits, why don't you just do it yourself before pushing the code to prod?"

I believe that the reason the chose to close the source is just security theater to demonstrate to investors and clients. "Look at all these FOSS projects getting pwned, that's why you can trust us, because we're not FOSS". There is, of course, probably a negative correlation between closing source and security. I'd argue that the most secure operating systems, used in fintech, health, government, etc, got to be so secure specifically by allowing tens or hundreds of thousands of people to poke at their code and then allowing thousands or tens of thousands of people to fix said vulns pro bono.

I'd be interested to see an estimation of the financial value of the volunteer work on say the linux or various bsd kernels. Imagine the cost of PAYING to produce the modern linux kernel. Millions and possibly billions of dollars just assuming average SWE compensation rates, I'd wager.

Too bad cal.com is too short sighted to appreciate volunteers.

Comment by msteffen 2 hours ago

> Millions and possibly billions of dollars just assuming average SWE compensation rates

Yeah, and average kernel devs are not average SWEs

Comment by bee_rider 2 hours ago

How are LLMs at reading assembly? I assumed they’d be able to read assembly about as well as any other language…

Is there such a thing as a closed source program anymore?

Comment by lrvick 2 hours ago

Not only are they good at reading and writing machine code now, they are actively being used to turn video game cartridge dumps back into open source code the community can then compile for modern platforms.

There is no moat anymore.

Comment by hungryhobbit 3 hours ago

If you believe they really did it for security, I have a very nice bridge to sell you for an extremely low price ...

Look, tech companies lie all the time to make their bad decisions sound less bad. Simple example: almost every "AI made us more efficient" announcement is really just a company making (unpopular) layoffs, but trying to brand them as being part of an "efficiency effort".

I'd bet $100 this company just wants to go closed source for business reasons, and (just like with the layoffs masquerading as "AI efficiency") AI is being used as the scapegoat.

Comment by rectang 3 hours ago

Who says I believe it? ;)

I'm just choosing to focus on the substance of the argument itself, which I think is risible regardless of who makes it and why.

Comment by dwedge 1 hour ago

It rubs me the wrong way that it says it's "the open source community edition". Who decided this was the one? How of the community is Claude? Why open source and not free software?

Maybe I'm being critical but the copy gives me the ick

Edit: I just realised this is by cal.com. I'm leaving my comment intact, if anything it adds to my ick

Comment by fencepost 2 hours ago

Can someone who's looked at the security of these systems give a bit more context on that?

The thing that's always concerned me with them is questions of "what level of access is required to the system(s) actually hosting my calendar data?" and "if this vendor is compromised, what level of access might an attacker in control of the vendor systems have?" Obviously this will vary by what kind of access controls backends have (e.g. M365, Google Workspace, assorted CRM systems, smaller cloud providers, self-hosted providers, etc.).

Edit: basically, with a lot of these systems, what's expected to be the authoritative data provider/storage?

Comment by ale 2 hours ago

Good grief that codebase is absolute hell, almost too good of an example of accidental complexity.

Comment by swyx 4 hours ago

are there notable open source forks or open source cal competitors that go for the "just keep it simple" vibe?

Comment by ezekg 3 hours ago

Thunderbird showed up in the last thread: https://github.com/thunderbird/appointment

Comment by 3 hours ago