Note that this is fundamentally different from the Astral acquisition. At the end of their announcement, they stated:
> Cirrus CI will shut down effective Monday, June 1, 2026.
And earlier in the article:
> Joining OpenAI allows us to extend the mission we started with Cirrus Labs: building new kinds of tooling and environments that make engineers more effective, for both human engineers and agentic engineers.
It isn't a product-led acquisition, but more a talent one.
This is kind-of neat too, at least in the near term:
> In the coming weeks, we will relicense all of our source-available tools, including Tart, Vetu and Orchard under a more permissive license. We have also stopped charging licensing fees for them.
Just want to note that we will continue maintaining and improving our virtualization solutions actually with even greater attention. SaaS options like Cirrus CI and Cirrus Runners will eventually wind down so we can focus on incorporating pieces internally.
You’ll be pleasantly surprised. Updates in the coming weeks.
> In the coming weeks, we will relicense all of our source-available tools, including Tart, Vetu and Orchard under a more permissive license. We have also stopped charging licensing fees for them.
If your scope includes making the Codex web app environments have additional functionality I look forward to it. More enterprise features and yaml backed pipelines.
Yeah. Much like Astral - acquiring both the product (because they need to use it internally, but don't care about trying to resell / market), and they also want the talent to keep maintaining it / add features they want.
I’m happy for the founders, they’re great folks. I contributed to CirrusCI a bit in the past and it was a great experience. I even advocated for Cirrus in a couple of my last $DAYJOBs (with varied success). Congrats Fedor!
I’m very sad they’re shutting down, though. IMHO CirrusCI was very close to a perfect CI system (I wrote a blogpost about it [0]). I’ll now have to find something to replace it with in my personal projects. I guess I’ll run their cirrus-cli in GitHub Actions for a while. But GitHub Actions is really poor. I heard some good things about Buildkite.
Having tried many other CI systems, all of which ultimately turned out to be subpar, it makes me incredibly sad to discover only now that Cirrus CI is (was?) quite a bit better than them. :( Thanks for the blog post, though!
Well, check out RWX! We don't do exactly everything like CirrusCI did -- most notably, we aren't open source and we are still managing all of our own infrastructure for running CI right now -- but we have a great "local" story and a validation CLI (`rwx lint`), and a lot of fundamental changes that make us better than other CI systems too :)
> Then, unprompted, Altman offers up a kind of shocking timeline for the groundbreaking feature of counting: “Maybe another year before something like that works well.” Per Altman, ChatGPT’s voice model doesn’t have the capability of starting a timer or keeping track of time. “But we will add the intelligence into the voice models,” he said.
Every great journey must have an end. As far as I understand Cirrus CI was struggling due to Github Actions eating their market. Cirrus CI was in my opinion much better than Github Actions but it is hard to compete with a bundled solution.
Same; the reason everyone ran out to buy Mac Minis last month is it gave their Claw access to iMessage, their browser cookies, and a residential IP. Cirrus provides a way to provision and orchestrate MacOS VMs, which is exactly what I did for running Openclaw (for a minute …).
Note that apples terms do not allow someone to sell something like an agent running on macOS. They have explicit cut outs for 24-hour minimum leases of full hardware, but they prohibit this with vms
Not to sell Tart short (it is quite good), but it's "just" a wrapper around Virtualization.framework with a few extra pieces. This is the kind of thing that Codex driven by experts _should_ be able to build very easily.
Agreed. The benefit from not having anyone else or any partial (container) solutions in the computing chain is huge for secure isolation. Getting rid of the intermediary solves a universe of possible problems.
That said, I've been free-riding on tart because they've often surfaced issues I needed to address. Free riders like me are possibly the reason these companies can't make their own way.
interesting that was what i thought this was, it keeps boggling my mind the sums being paid for what really could be built by experienced devs on their own teams
You don't want a 40-men strong team that needs to be managed, you want 2 guys that already did it and are hungry for the next 10 problems all on their own.
"Hey guys, make our agents verify tool use before responding to the user. See you in 2 months. Here's 2$b"
The level of aqui-hires is getting interesting - at this point, it appears that if one wants one's career to progress, you need to start some kind of tiny startup like Astral or Bun and hope to be notable enough you can get acquired by someone like OpenAI or Anthropic.
It certainly makes the idea of a career progression / promotion more challenging than it used to be, but perhaps it also opens up some new opportunities. It becomes far more "high stakes" since you have to take the risk of starting and running a startup that ultimately fails if it does not get acqui-hired.
It also kills competition and disincentivizes providing long term value. I’m not sure how making the job market more like gambling does anything positive for the majority of people
It’s been true for a while, but AI seems to have exaggerated it. To me it reinforces the idea that LLMs created a “K” shaped talent market. Those whose are good become even more valuable.
> at this point, it appears that if one wants one's career to progress, you need to start some kind of tiny startup like Astral or Bun and hope to be notable enough you can get acquired by someone like OpenAI or Anthropic
This has been popular for 25+ years. Likely before, but that's when I first started noticing a significant number of companies that were clearly in business solely TO BE BOUGHT.
Been there, done that, and I still find value in 3rd party services despite the occasional need to migrate.
Self hosting is the way to go if you need to keep monthly services spend as low as possible but you have extra time to spend, such as with a hobby project.
Whenever I’ve worked on real startup projects, self-hosting became a constant source of little tasks for the engineering team to mix into our weekly workload. There were always little tasks to upgrade this service, investigate why that one server was slow, or to migrate something to a bigger server because we were bottlenecked on some resource. Then we had to manage backups and do our recovery drills, along with changing the backup strategy every 6 months because someone had a better idea.
When we started to add up all of the time spent managing everything it starts to look like spending dollars (of engineer time) to save pennies on SaaS bills.
Probably not a popular thing to say on HN, but I now try to stay away from teams that go to extremes to self-host everything because I just want to get my work done, not also be constantly involved in running the underlying services. I do it for my own hobby projects at home but I don’t want to be doing it at work where we have money to spend to lighten the load. If the cost is the occasional migration to a different 3rd party service that’s not a big workload relative to everything involved in self-hosting.
>if you need to keep monthly services spend as low as possible but you have extra time to spend, such as with a hobby project.
We did not have any budget constraints at all.
Depending on 3rd party meant:
1. Begging for issues where project owner has marked them "won't fix"
2. Navigating hundreds of features we don't use, don't need and not having features we absolutely need but they don't have.
3. Weird gotchas and cost saving implemented by them, where we do not want to save any money.
>When we started to add up all of the time spent managing everything it starts to look like spending dollars (of engineer time) to save pennies on SaaS bills.
We actually factored all costs, our self hosted solution are "very lean" and still come out ahead when you factor in time/cost.
>spending dollars (of engineer time) to save pennies on SaaS bills.
I ran by this for long time fasely believing "engineers are way more expensive than cloud bills, so these thousands of dollars we are spending on these services don't matter"
but when we actually got down to fixing all , we realised now it costs us 1/10th of what it used to with more flexibility and reliability.
>Probably not a popular thing to say on HN, but I now try to stay away from teams that go to extremes to self-host everything because I just want to get my work done, not also be constantly involved in running the underlying services
we found exact opposite tbh, integrating into others hurt our performance, wasted our time, made us frustrated and desperate.
Only external service we use now are Anycast for serving our sub millisecond api and "billing", yes billing because it has lots of edge cases, taxes and all wicked things we can't manage on our own.
Still looking to rollout inhouse biller soon though.
That is something of a broken promise in the SaaS world; it was supposed to be convenience but instead it became a hundred broken integration points as you struggle to keep up with deprecated APIs and acqui-hires killing off shims you wouldn't have needed if everything had been on-prem to begin with.
- gitea
- woodpecker CI
- my own docker registry
- portainer running on my docker swarm
I then define the docker stack in the git repository, and CI builds the images and pushes to build the new image to the docker repository. The portainer API allows to deploy a stack, with the image tag as a parameter.
Cirrus gave a ton of support for years to open source projects. I congratulate them on cashing out. Running a business like Cirrus did is always a hard road and I will never fault folks who gave time and resources on their platform away for taking the money.
I wish Fedor and everyone at Cirrus the best of luck and OpenAI and thank them immensely for the years of free CI they gave to us in the Pony programming language despite it not having any marketing value to them.
Wow Cirrus was like the one cool CI thing with first-class Podman support. RIP. Guess I'm looking elsewhere (and not at Dagger which refuses to support rootless Podman).
A pity. Cirrus has been providing quite decent CI facilities, for free. One of the advantages (among many) compared to GitHub Actions is the large variety of runner images, e.g., Debian, Fedora, Alpine, FreeBSD, ...
This is a VC site. Morality or changing the world for the better is window dressing on earning as much money as possible and damn anyone who gets in the way. Morality is only good in as much as it’s good for business to be seen as moral. Money people have been majority running things for over 2 decades at least but the mythos lives on.
Interesting move. Cirrus Labs has been doing solid work in mobile CI/CD infrastructure — curious to see how their expertise gets integrated into OpenAI’s tooling and developer ecosystem.
It's hard not to imaging that OpenAI is attempting to build an developer tools eco-system. It makes sense as it's one of the few fields in AI that are currently able to generate sales.
Tart is an amazing tool, and I have been very grateful for it. There's almost no other way I've found to stand up ephemeral CI/CD macOS VMs for self-hosted Git forge solutions. I really hope this doesn't mean that Tart will eventually die the death of unmaintained projects (e.g. Realm post-Mongo-acquisition.)
> We are no longer accepting new customers for Cirrus Runners but will continue supporting the service for existing customers through their existing contract periods.
I mean, it’s no different than any other company who goes out of business. Yeah, their star rating on Yelp is gonna take a major hit, but on the other hand, they don’t exist anymore so shrug feel free to hold a grudge against them, I guess.
This is the risk we run when we get services from companies that aren’t Microsoft, IBM, etc. (I would say Google but LOL, they obviously kill products even faster than the startup death cycle).
Thank you! Full journey is too long for a comment here.
It was hard and I was lucky with my previous pre-IPO gigs at Airbnb and Twitter so I had some bootstrap fund. In retrospective a dev tools startup in 2017 with no network and no VC support was a crazy idea but I was young and didn’t think thought too much.
Then it was long 8 years of raw work and constant questioning this choice. Then finally a third component: luck. In 2024-2025 it kind of grew organically due to market changes and back in October 2025 I finally stopped questioning the future of Cirrus Labs.
My only advice if I may, try to get your first dollar from your startup while you are employed.
To create an ephemeral (docker-like) MacOS VM on a Mac with full performance and access (e.g. GPU) you have to use a virtualization API provided by Apple.
For most CI use, you can choose between:
Anka, a "contact-us for pricing" closed-source projet, where you have to pay expensive license (easy 3000 USD/yr per machine)
or
tart, which is a lightweight wrapper around the official Apple API.
But you have to know that on MacOS, there is an artificial limit of 2 VMs per Mac... but well:
I just love how companies like this gaslight the whole world with announcements like this.
We started a company to make a big difference in the world and build an engineer’s dream company, and that’s why we have now decided to do the exact opposite and become employee numbers 32,463 through 32,510 at one of the largest tech companies in the world because money is nice.
Look, I’d have done the same thing, I’m not criticizing the choice. I just think we don’t need this kind of weird unnatural rhetoric.
Please just stop with the tech industry puffery. You’re not Steve Jobs, you’re just the DevOps team at OpenAI now. You’re dumping your worthless code on GitHub, and you’re kicking your customers to the curb.
There’s no PR spin left to do anymore. You’re not a company anymore and you’re not a founder anymore.
I just don't think there's much upside to telling it how it is in the press release that gets buried after a week and everyone moves on. For better or worse.
Maybe it’s just my age or how my brain works, but positivity with a touch of BS is just business-speak. My company sold itself to a crappy company who fired most of us, but my departure message for my colleagues was full of “I’ve enjoyed this journey, it’s been a privilege, blah blah” and not “I’ve actually been counting down the days to be done with this nonsense since even before the acquisition.”
You say this stuff because we all agree to sugar coat this type of thing. We all love money and most of us would sell a clearly-never-going-to-be-unicorn company we founded to just about any company if they offered a price that would make you or your whole team set for life. Like, I’d sell to Salesforce, or IBM, or Oracle, or Microsoft or Apple, or Monster Cable, or Ticketmaster. At least half of those, most of us would say are not innovative, and would ruin the product. But no one wants to work with or hire someone who comes right out and says “I hope we sell the company to some rich jerks (ANY rich jerks, really!) so I can retire to the Bahamas.”
There is a theme in a lot of products (and open source projects) of plastering AI all over the description, even if it isn't really related to AI. The first thing I see on the CirrusLabs website is "Accelerate AI Adoption Without Compromising Safety". How am I supposed to know this is a CI product, and even if I figure that out, how am I supposed to know it is a genral CI tool and not something AI specific?
I don't understand why these sites just put a bunch of buzzwords instead of telling you what it actually is.
We have AI companies constantly fear-mongering that their next model is somehow too dangerous to release. But they just continue to go on an acquisition spree.
This just confirms to me that we are no where near AI being able to write any complicated software. I mean, if it could woudln't OpenAI just prompt it into existence? ;)
> We have AI companies constantly fear-mongering that their next model is somehow too dangerous to release
I'm guessing you're referring to this recent report of the security vulnerabilities Mythos found and submitted patches for? That just seems like they don't want the negative press and/or liability if their new model ends up being used to create 0-days that cause widespread damage.
> Cirrus CI will shut down effective Monday, June 1, 2026.
And earlier in the article:
> Joining OpenAI allows us to extend the mission we started with Cirrus Labs: building new kinds of tooling and environments that make engineers more effective, for both human engineers and agentic engineers.
It isn't a product-led acquisition, but more a talent one.
> In the coming weeks, we will relicense all of our source-available tools, including Tart, Vetu and Orchard under a more permissive license. We have also stopped charging licensing fees for them.
Hopefully development on it continues, or a community maintained version keeps it going.
https://github.com/cirruslabs/tart/blob/main/LICENSE
https://tart.run/licensing/
> In the coming weeks, we will relicense all of our source-available tools, including Tart, Vetu and Orchard under a more permissive license. We have also stopped charging licensing fees for them.
If you’re taking requests…
https://github.com/smogili1/circuit
Looks like I’ll need to move the FreeBSD CI jobs for open source projects I maintain to another solution. Anyone have suggestions for alternatives?
https://github.com/scipy/scipy/issues/24990
https://www.postgresql.org/message-id/3ydjipcr7kbss57nvi67no...
https://en.wikipedia.org/wiki/Cirrus_Logic
I’m happy for the founders, they’re great folks. I contributed to CirrusCI a bit in the past and it was a great experience. I even advocated for Cirrus in a couple of my last $DAYJOBs (with varied success). Congrats Fedor!
I’m very sad they’re shutting down, though. IMHO CirrusCI was very close to a perfect CI system (I wrote a blogpost about it [0]). I’ll now have to find something to replace it with in my personal projects. I guess I’ll run their cirrus-cli in GitHub Actions for a while. But GitHub Actions is really poor. I heard some good things about Buildkite.
[0]: https://garden.pacia.tech/cirrus_ci_is_the_best.html
Having tried many other CI systems, all of which ultimately turned out to be subpar, it makes me incredibly sad to discover only now that Cirrus CI is (was?) quite a bit better than them. :( Thanks for the blog post, though!
@sama if you need someone to buy to implement timers for ChatGPT I’m your guy - my price is 2 billion dollars.
--
https://gizmodo.com/sam-altman-says-itll-take-another-year-b...
Then I remembered scripting existed ^_^
> In 2022, we built Tart, which became the most popular virtualization solution for Apple Silicon, along with several other tools along the way.
from Tart's github:
> [Tart is for] macOS and Linux VMs on Apple Silicon to use in CI and other automations
My (naive?) hypothesis is this kind of expertise is why OpenAI chose to acquihire.
That said, I've been free-riding on tart because they've often surfaced issues I needed to address. Free riders like me are possibly the reason these companies can't make their own way.
"Hey guys, make our agents verify tool use before responding to the user. See you in 2 months. Here's 2$b"
Long term: they now have experienced dev(s?) to build their next products and features
It certainly makes the idea of a career progression / promotion more challenging than it used to be, but perhaps it also opens up some new opportunities. It becomes far more "high stakes" since you have to take the risk of starting and running a startup that ultimately fails if it does not get acqui-hired.
This has been popular for 25+ years. Likely before, but that's when I first started noticing a significant number of companies that were clearly in business solely TO BE BOUGHT.
Today we use Hertzner and OVH and roll out our own solution whenever possible.
Running lean and mean.
Depending on such third party services is a trap.
Self hosting is the way to go if you need to keep monthly services spend as low as possible but you have extra time to spend, such as with a hobby project.
Whenever I’ve worked on real startup projects, self-hosting became a constant source of little tasks for the engineering team to mix into our weekly workload. There were always little tasks to upgrade this service, investigate why that one server was slow, or to migrate something to a bigger server because we were bottlenecked on some resource. Then we had to manage backups and do our recovery drills, along with changing the backup strategy every 6 months because someone had a better idea.
When we started to add up all of the time spent managing everything it starts to look like spending dollars (of engineer time) to save pennies on SaaS bills.
Probably not a popular thing to say on HN, but I now try to stay away from teams that go to extremes to self-host everything because I just want to get my work done, not also be constantly involved in running the underlying services. I do it for my own hobby projects at home but I don’t want to be doing it at work where we have money to spend to lighten the load. If the cost is the occasional migration to a different 3rd party service that’s not a big workload relative to everything involved in self-hosting.
We did not have any budget constraints at all.
Depending on 3rd party meant:
1. Begging for issues where project owner has marked them "won't fix"
2. Navigating hundreds of features we don't use, don't need and not having features we absolutely need but they don't have.
3. Weird gotchas and cost saving implemented by them, where we do not want to save any money.
>When we started to add up all of the time spent managing everything it starts to look like spending dollars (of engineer time) to save pennies on SaaS bills.
We actually factored all costs, our self hosted solution are "very lean" and still come out ahead when you factor in time/cost.
>spending dollars (of engineer time) to save pennies on SaaS bills.
I ran by this for long time fasely believing "engineers are way more expensive than cloud bills, so these thousands of dollars we are spending on these services don't matter"
but when we actually got down to fixing all , we realised now it costs us 1/10th of what it used to with more flexibility and reliability.
>Probably not a popular thing to say on HN, but I now try to stay away from teams that go to extremes to self-host everything because I just want to get my work done, not also be constantly involved in running the underlying services
we found exact opposite tbh, integrating into others hurt our performance, wasted our time, made us frustrated and desperate.
Only external service we use now are Anycast for serving our sub millisecond api and "billing", yes billing because it has lots of edge cases, taxes and all wicked things we can't manage on our own.
Still looking to rollout inhouse biller soon though.
Cost savings are insane and the speed of latest amd epycs are miles ahead of the default ci instances on github and other places.
I wish Fedor and everyone at Cirrus the best of luck and OpenAI and thank them immensely for the years of free CI they gave to us in the Pony programming language despite it not having any marketing value to them.
So they want an integrated solution with CI, Python packaging and vibe coding.
That is a $100 million valuation at best, not a $1 trillion one.
Proceeds to buy white collar workers.
orchestration
docker / virtualization framework is for one machine
this stuff is for 100s - 1000s machines
https://news.ycombinator.com/item?id=47704497
> We never raised outside capital
I guess it worked out though
Do service providers not think customers have other things to do than simply maintain their existing infrastructure?
Plus migration is super easy with Cirrus CLI -- tool to run our CI task definitions locally or in any CI. See https://github.com/cirruslabs/cirrus-cli
> We are no longer accepting new customers for Cirrus Runners but will continue supporting the service for existing customers through their existing contract periods.
This is the risk we run when we get services from companies that aren’t Microsoft, IBM, etc. (I would say Google but LOL, they obviously kill products even faster than the startup death cycle).
Can you talk a bit more about your journey without raising funds?
Also what does HN think of that path today when trying to launch a new AI startup?
It was hard and I was lucky with my previous pre-IPO gigs at Airbnb and Twitter so I had some bootstrap fund. In retrospective a dev tools startup in 2017 with no network and no VC support was a crazy idea but I was young and didn’t think thought too much.
Then it was long 8 years of raw work and constant questioning this choice. Then finally a third component: luck. In 2024-2025 it kind of grew organically due to market changes and back in October 2025 I finally stopped questioning the future of Cirrus Labs.
My only advice if I may, try to get your first dollar from your startup while you are employed.
I am too late for that as I am full time but also lucky to have had a previous exit.
I am planning to go the VC route this time, because the problem I am going after feels VC size.
However I feel bootstrap or small F&F round gives you more flexibility when it comes to exits.
Congrats again!
That said, I find their aqui-hire by OpenAI disappointing for a number of (mostly personal) reasons. However, I wish them the best regardless.
For most CI use, you can choose between:
or But you have to know that on MacOS, there is an artificial limit of 2 VMs per Mac... but well:https://github.com/cirruslabs/orchard/commit/3cfa2445500f45f...
With https://khronokernel.com/macos/2023/08/08/AS-VM.html
Some people might find it very attractive:
Even without bypassing the limit it is great actuallyhttps://developers.openai.com/api/docs/guides/tools-computer...
https://github.com/cirruslabs/mtell
It's kind of like electric cars charged with electricity from coal power plants.
We started a company to make a big difference in the world and build an engineer’s dream company, and that’s why we have now decided to do the exact opposite and become employee numbers 32,463 through 32,510 at one of the largest tech companies in the world because money is nice.
Look, I’d have done the same thing, I’m not criticizing the choice. I just think we don’t need this kind of weird unnatural rhetoric.
Please just stop with the tech industry puffery. You’re not Steve Jobs, you’re just the DevOps team at OpenAI now. You’re dumping your worthless code on GitHub, and you’re kicking your customers to the curb.
There’s no PR spin left to do anymore. You’re not a company anymore and you’re not a founder anymore.
I’m sure there’s a way to say the same thing without coming across as a bullshitter.
If this is a forgettable press release isn't it lower effort than coming up with this type of nonsense?
You say this stuff because we all agree to sugar coat this type of thing. We all love money and most of us would sell a clearly-never-going-to-be-unicorn company we founded to just about any company if they offered a price that would make you or your whole team set for life. Like, I’d sell to Salesforce, or IBM, or Oracle, or Microsoft or Apple, or Monster Cable, or Ticketmaster. At least half of those, most of us would say are not innovative, and would ruin the product. But no one wants to work with or hire someone who comes right out and says “I hope we sell the company to some rich jerks (ANY rich jerks, really!) so I can retire to the Bahamas.”
I don't understand why these sites just put a bunch of buzzwords instead of telling you what it actually is.
This just confirms to me that we are no where near AI being able to write any complicated software. I mean, if it could woudln't OpenAI just prompt it into existence? ;)
I'm guessing you're referring to this recent report of the security vulnerabilities Mythos found and submitted patches for? That just seems like they don't want the negative press and/or liability if their new model ends up being used to create 0-days that cause widespread damage.
https://red.anthropic.com/2026/mythos-preview/