Cal.diy: open-source community edition of cal.com (github.com)
206 points by petecooper 16 hours ago
FlamingMoe 15 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...
Ethee 15 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.
loa_in_ 15 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.
tecoholic 13 hours ago
This actually makes me wonder if cal.com has had a security breach in their hosted offering that they are not disclosing.
sqircles 13 hours ago
Reubend 7 hours ago
But the OSS license already absolves them of responsibility. This might just be to set the tone that security fixes won't be prioritized to the standard that they used to be.
cortesoft 6 hours ago
sreekanth850 14 hours ago
I still remember when they launched here. "Opensource Alternate to Calendly" was their post title.
fnoef 14 hours ago
What do you want, it’s hard to resist VC money and “the enterprise offering”
theturtletalks 12 hours ago
spiderfarmer 13 hours ago
_ache_ 14 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
preya2k 13 hours ago
Seems to be mostly vibe coded.
hocuspocus 12 hours 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.
_ache_ 12 hours ago
Yes, sadly. :(
luckydata 9 hours ago
Who gives a shit. Cal.com is written by hand and the code is absolute garbage. Of all people that should be luddites I never imagined software engineers would be the most pointlessly staunch advocates of that philosophy.
ramon156 14 minutes ago
liamgm 3 hours ago
sadly it's one of the strictly viral license AGPL , i prefer the more permisive one
conradev 13 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
chrysoprace 9 hours ago
Bonus: if you pick cal.zone you can have fun with pizza puns.
singiamtel 12 hours ago
I'm surprised cal.zone is not taken already
holistio 8 hours ago
It still isn't taken but it's now $20k.
raphaelcosta 15 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.
jiusanzhou 3 hours ago
The irony of labeling this 'not recommended for production' while it's a fork of your own previously production-grade OSS is hard to miss. Feels less like a community edition and more like a liability shield. Curious how long before an actual community fork ends up being the thing people self-host.
OsrsNeedsf2P 14 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
dabeeeenster 13 hours ago
How curious. Are they trying to throw security shade on running open source? Very odd.
j1elo 13 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.
bluehatbrit 15 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?
geoffschmidt 15 hours ago
rectang 14 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.
goodmythical 13 hours ago
63stack 3 hours ago
bee_rider 13 hours ago
hungryhobbit 14 hours ago
lrvick 13 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
pnw_throwaway 13 hours ago
You might want to double-check the cal.diy maintainer before your wish is granted..
neerajdotname2 6 hours ago
If you are looking for an alternative then please take a look at NeetoCal https://neeto.com/cal . It's closed source though.
Disclosure: I'm the CEO of NeetoCal.
fencepost 13 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?
dwedge 12 hours 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
ale 13 hours ago
Good grief that codebase is absolute hell, almost too good of an example of accidental complexity.
luckydata 9 hours ago
It is total dogshit. I looked at it once and i was very much not impressed.
swyx 15 hours ago
are there notable open source forks or open source cal competitors that go for the "just keep it simple" vibe?
ezekg 14 hours ago
Thunderbird showed up in the last thread: https://github.com/thunderbird/appointment