Phoenix.new – The Remote AI Runtime for Phoenix
35 comments
·June 20, 2025chrismccord
tiffanyh
Amazing work.
Just a clarifying question since I'm confused by the branding use of "Phoenix.new" (since I associate "Phoenix" as a web framework for Elixir apps but this seems to be a lot more than that).
- Is "Phoenix.new" an IDE?
- Is "Phoenix.new" ... AI to help you create an app using the Phoenix web framework for Elixir?
- Does "Phoenix.new" require the app to be hosted/deployed on Fly.io?
- Is it all 3 above?
arrowsmith
Thanks for everything you do Chris! Keep crushing it.
troupo
I know it's early days, but here's a must-have wish list for me:
- ability to run locally somehow. I have my own IDE, tools etc. Browser IDEs are definitely not something I use willingly.
- ability to get all code, and deploy it myself, anywhere
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Edit: forgot to add. I like that every video in Elixir/Phoenix space is the spiritual successor to "15-minute rails blog" from 20 year ago. No marketing bullshit, just people actually using the stuff they build.
chrismccord
You can push and pull code to and from local desktop already: hamburger menu => copy git clone/copy git push.
You could also have it use GitHub and do PRs for a codex/devin style workflows. Running phoenix.new itself locally isn't something we're planning, but opening the runtime for SSH access is high on our list. Then you could do remote ssh access with local vscode or whatever.
chrismccord
"15-minute rails blog" changed the game so I definitely resonate with this. My videos are pretty raw, so happy to hear it works for some folks.
arrowsmith
Ah man I'm really happy to see this and excited to try it out.
As an Elixir enthusiast I've been worried that Elixir would fall behind because the LLMs don't write it as well as they write bigger languages like Python/JS. So I'm really glad to see such active effort to rectify this problem.
We're in safe hands.
mrcwinn
Worried it might fall behind… further? I love LiveView, Phoenix, Elixir, OTP. But the ecosystem is a wasteland of abandoned packages.
If Phoenix.new helps solve that problem, I’m all for the effort. But otherwise, the sole focus of the community leaders of Elixir should be squarely and exactly focused on creating the incentives and dynamics to grow the base.
Compare, for example, Mastra in TypeScript or PydanticAI in Python. Elixir? Nothing.
Not here to bash. It’s more just a disappointment because otherwise I think nothing comes close.
uncircle
All languages are a wasteland of abandoned packages, i.e. there is a very long tail of stuff no one has maintained for years. It’s all relative to the mindshare. For its size, Elixir is doing quite well.
erichocean
Most languages require maintenance.
Some languages—Clojure is a good example—have packages from 10 years ago, entirely unmaintained, that still work great because no maintenance is needed.
conradfr
Old packages usually still run great in Elixir though.
acedTrex
LLMs not writing it well might be the biggest current selling point of elixir lol.
null
zorrolisto
Same, I watched a video from Theo where he says Next.js and Python will be the best languages because LLMs know them well, but if the model can infer, it shouldn’t be a problem.
rramon
Folks on YouTube have used Claude Code and the new Tidewave.ai MCP (for Elixir and Rails) to vibe code a live polling app in Cursor without writing a line of code. The 2hr session is on YT.
dingnuts
since models can't reason, as you just pointed out, and need examples to do anything, and the LLM companies are abusing everyone's websites with crawlers, why aren't we generating plausible looking but non working code for the crawlers to gobble, in order to poison them?
I mean seriously, fuck everything about how the data is gathered for these things, and everything that your comment implies about them.
The models cannot infer.
The upside of my salty attitude is that hordes of vibe coders are actively doing what I just suggested -- unknowingly.
Imustaskforhelp
For what its worth, AI already has subpar data. Atleast this is what I've heard.
I am not sure, but the cat is out of the box. I don't think we can do anything at this point.
fragmede
But the models can run tools, so wouldn't they just run the code, not get the expected output, and then exclude the bad code from their training data?
sieabahlpark
[dead]
throwawaymaths
in principle llms should do better on immutable languages since there is no risk a term will get modified by a distant function call.
bevr1337
In my experience, it's the functional part, not immutability, where they fall short. Any LLM can write immutable C# because it's easy and there's incredible amounts of training data.
throwawaymaths
good news, "immutable" is pretty much the only way that elixir is "functional" except for lambdas being first class datatypes (which is almost every language now)
nilirl
Beautiful demo! How do I build agents like this?
Does anyone know any great resources to learn how to design agents? Tool agnostic resources would be awesome.
pier25
I'm surprised they are investing into this. I checked Phoenix recently because I was interested in LiveView and there isn't even an official AWS SDK for Elixir.
Honestly doubt the AI stuff is going to move the needle much if you can't even have a dependable S3 client.
techpression
Considering the horror the official AWS CLI is this seems like a strange example. I’ve used both the non official libraries and they work fine. The one that is auto generated doesn’t feel very Elixir, but that’s to be expected.
olafura
What are you talking about, there has been a AWS client forever and I've never had a problem. It's not something you really need an official sdk for they are anyway often just reference because you might want different performance characteristics.
https://hex.pm/packages/ex_aws https://hex.pm/packages/ex_aws_s3
I've usually not seen more than 3 or so official SDK for most services and there are a lot more programming languages than that. For example Microsoft's Graph API doesn't have an official Ruby client, they have one that sort of works.
conradfr
But there's two actively non-official maintained libs.
themgt
This looks really cool, but I gotta say I'm a uneasy with the apparent(?) closed-source + hosted + branding. "mix phx.new" is the way to generate a new Phoenix project, but "Phoenix.new" is closed source Fly.io product for building Phoenix projects?
Feels like we're getting into a weird situation if LLM providers are publishing open source agentic coding tools and OSS web app frameworks are publishing closed source/non-BYOK agentic coding tool. I realize this may not be an official "Phoenix" project but it seems analogous to DHH releasing a closed-source/hosted "Rails.new" service.
martypitt
This is really cool! And, that you did it in a few weeks is insane.
How did you get VS Code embedded in your app? I'm aware of projects like Monaco, and that vscode.dev exists - so it's clearly possible - but I didn't realize it was something others could build upon?
Again, kudos!
moffers
The mental models of Elixir/OTP and AI Agents are very compatible. I’ve felt for a long time that it would be one of the best platforms for building AI agents.
rramon
Very cool. Does it use Phoenix 7 or 8 in the video?
ipnon
Chris is a hacker’s hacker.
Phoenix creator here. I'm happy to answer any questions about this! Also worth noting that phoenix.new is a global Elixir cluster that spans the planet. If you sign up in Australia, you get an IDE and agent placed in Sydney.