This is amazing on multiple fronts! I reset your usage, so the next round is on us! We shipped credits the day before launch, so usage UI is still TBD, but should be out next week. Thanks for the sharing your experience!

Was the graphic design created from prompts too? It's surprisingly nice, especially considering you spent 45 minutes on it.

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? If that's the case, maybe a naming like "phoenix.flyio.new" would be better and extensible for any type of service Fly.io helps in deployment - Phoenix/Elixir being one)

- Is it all 3 above?

And how does this compare to Tidewave.ai (created as presumably you know, by Elixir creator)

Apologies if I'm possibility conflating topics here.

The Phoenix.new environment includes a headless Chrome browser that our agent knows how to drive. Prompt it to add a front-end feature to your application, and it won’t just sketch the code out and make sure it compiles and lints. It’ll pull the app up itself and poke at the UI, simultaneously looking at the page content, JavaScript state, and server-side logs.

Is it possible to get that headless Chrome browser + agent working locally? With something like Cursor?

Include optional default email, auth, analytics, job management (you know… the one everyone uses ::cough:: Oban ::cough::), dev/staging/prod modes (with “deployment” or something akin to CD… I know it’s already in the cloud, but you know what I mean) and some kind of non-ephemeral disk storage, maybe even domain management… and this will slay. Base44 just got bought for $80M for supplying all those, but nothing is as cool as Elixir of course!

These other details that are not “just coding” are always the biggest actual impediments to “showing your work”. Thanks for making this!! Somehow I am only just discovering it (toddler kid robbing my “learning tech by osmosis” time… a phenomenon I believe you are also currently familiar with, lol)

Watched the Tetris demo of this and it was very impressive. I was particularly surprised how well it seems to work with the brand-new scopes, despite the obvious lack of much prior art. How did you get around this, how much work was the prompt, and are you comfortable sharing it?

Is there a transparent way to see credit used/remaining/topped up, and do you have any tips for how you can prompt the agent that might offer more effective use of credits?

The LLM chat taps out but I can't find a remaining balance on the fly.io dashboard to gauge how I'm using it. I _can_ see a total value of purchased top ups, but I'm not clear how much credit was included in the subscription.

It's very addictive (because it is awesome!) but I've topped up a couple of times now on a small project. The amount of work I can get out the agent per top-up does seem to be diminishing quite quickly, presumably as the context size increases.

Hi just to confirm as I cannot find anything related to security or your use of using submitted code for training purposes. Where is your security policies with regards to that.

Is there something comparable that works similarly but completely offline with appropriate hardware? Not everywhere has internet or trusts remote execution and data storage.

PS: Why can't I get IEx to have working command-line history and editing? ;-P

Any takeaways on using Fly APIs for provisioning isolated environments? I'm looking into doing something similar to Phoenix.new but for a low-code server-less workflow system.

1. What's your approach to accessibility? Do you test accessibility of the phoenix.new UI? Considering that many people effectively use Phoenix to write front-ends, have you conducted any evals on how accessible those frontends come out?

2. How do you handle 3rd party libraries? Can the agent access library docs somehow? Considering that Elixir is less popular than more mainstream languages, and hence has less training data available, this seems like an important problem to solve.

Just tried it out, but it's unclear what the different buttons at the bottom of the chat history does. The rightmost one (cloud with an upwards arrow) seems to do the same as the first?

What LLM(s) is the agent using? Are you fine-tuning the model? Is the agent/model development a proprietary effort?

This looks amazing! I keep loving Phoenix more the more I use it.

I was curious what the pricing for this is? Is it normal fly pricing for an instance, and is there any AI cost or environment cost?

And can it do multiple projects on different domains?

Do you have a package for calling LLM services we can use? This service is neat, but I don't need another LLM IDE built in Elixir but I COULD really use a way to call LLMs from Elixir.

Thanks for everything you do Chris! Keep crushing it.

How tightly coupled to Fly.io are generated apps?

I'm assuming you're using FLAME?

How do you protect the host Elixir app from the agent shell, runtime, etc

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.

how are they isolating ai agent state from app-level processes without breaking BEAM's supervision guarantees?

this spins up a live elixir cluster per user session. how they handling hot code reloads across distributed nodes?

the ai agent runs inside the same remote runtime as the app. does it share the BEAM vm or run as a port process?

What is the benefit of this vs. just running your agent of choice in any ole container?

look into Kasm workspaces.. great way to spin up remote docker-based linux desktops, and works great as an AI dev environment that you can use wherever you happen to be. There is homedir persistence, and package persistence can be achieved via some extra configuration that allows for Brew homedir-based package persistence.

https://hub.docker.com/r/linuxserver/kasm

https://www.reddit.com/r/kasmweb/comments/1l7k2o8/workaround...

I have recently been working with Google Jules and it has a similar approach. It spins up VMs and goes through tasks given.

It does not handle any infrastructure, so no hosting. It allows me to set multiple small tasks, come back and check, confirm and move forward to see a new branch on GitHub. I open a PR, do my checks (locally if I need to) and merge.

>> Remote agent - it's a containerized environment where the agent can run loose and do whatever

How is this innovation?

LLMs not writing it well might be the biggest current selling point of elixir lol.

This is such a weird meme, Claude crushes elixir especially a fullstack app in liveview

This last few weeks I've been going hard on LLMs to put together a new prototype project. I've exclusively been using Claude Sonnet 3.7 within Zed (via github copilot) and it' fantastic.

From time to time it tries to do something a little old-school, but nothing significant really. It's very capable at spitting out entire new features, even in liveview.

Over all the experience has very productive, and at least on-par with my recent work on similar sized python and nextjs applications.

I think because I'm using mostly common and well understood packages it has a big leg up. I also made sure to initialise the phoenix project myself to start with so it didn't try to go off on some weird direction.

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.

I found them to be pretty solid for writing Elixir (not perfect but neither is it with JS) the last couple of months.

in principle llms should do better on immutable languages since there is no risk a term will get modified by a distant function call.

Yeah – as someone who works in Common Lisp, I wish there was way to do complementary training for LLMs with existing corpora of codebases. Being able to read access documentation doesn't do much, unfortunately, to help with more general issues with correctness of output.

I use o3, it's really good with Elixir. I prefer it to Claude, but Claude does a decent job as well.

If you want to take your website and business down, use ChatGPT-4o's code

Claude 3.5 produces very good Elixir/Phoenix code. Haven't tried 3.7 much but I assume it's only going to get better from here

Claude and o3 are both excellent (if a bit erratic) elixir developers.

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.

This is a situation where we've been pushing on Chris to get this out into the world quickly, and there's a lot of packaging stuff like this that isn't fully put together yet. Thanks for calling it out! We'll get to it over the next week.

Same. Agents can be very expensive. Plus I have no idea how reliable or effective this actually is in practice. Would love to try it first.

LLMs are definitely a lot better at Elixir than they used to be - the gap has closed somewhat. I still perceive a gap though, especially when trying to do more complicated things in Phoenix and LiveView (as opposed to just raw Elixir.)

Which LLMs do you use that you find are best with Elixir/Phoenix?

I've only used LLMs with Elixir, so I don't have any other experience for comparison, but I've found that although Claude frequently employs the wrong approaches in Elixir, I usually know when he'll have trouble and just ask him to read pertinent documentation first. So long as he's read the manual he seems to do just fine.

TIL; That is a very interesting library

I think it boils down to: if the AI screws up what I asked it to do, who do I have to hold accountable? If the answer is that there is no one I can hold accountable, because the AI agent I used removes any and all onus of responsibility in its terms of service, then I'm not going to use it for anything non-trivial.

I don't think we want to move to a world where everything we use is AI driven all the time.

A coded app is significantly more efficient to execute, and more predictable, than dealing with AI in most situations.

Would you elaborate why?

The answer is yes. What would you say then?

There’s a “clone Git repo” thing in the left side bar, use that to clone the project locally, mix deps.get, mix phx.serve and you’re up. You can deploy this anywhere you want.

It’s just producing Elixir/Phoenix code that is stored in GitHub and can be deployed anywhere.

You can just use git to clone the code

Thanks for the feedback! Send your fly email to chris@fly.io and I'll get things sorted out. We'll throw you some credits for the trouble :)

I'm with you. I'm going to try Zed in the next couple days based on the response to my comment here. https://news.ycombinator.com/item?id=44322560 . I'm stuck with vim. My fingers nearly only work vim, but I managed to move to neovim, which worked. Maybe (something else) can work too.

You can pull the repo, tweak it locally with Vim, push it back and ask the LLM to work on top of that. No need to use the built in IDE if you don’t like it.

It's not really about the remote IDE. It's about an integrated environment where the agent can do everything it needs (install OS packages, inspect the code, view the app via a browser etc) in order to build what you want. It could end up being the place you 'start' an app, before exporting it and fleshing out the features locally.

What you mean by performs bad in LLMs?

Thanks! Everything is overly complicated in this space. It's probably far easier than you think. The open secret is it's just a loop that POST [provider]/chat/completions.

Elixir is particularly well suited here. In Elixir this is a genserver doing http posts and reacting to the token stream. The LiveView chat gets messages from the genserver agent regardless of where it is on the planet, and the agent also communicates with the phoenix channel websocket talking to the IDE machines with regular messages, again anywhere they are on the planet.

I talk about this quite a bit in my ElixirConfEU talk and distill things down: https://youtu.be/ojL_VHc4gLk?si=MzQmz-vofWxWDrmo&t=1040

A hacker's hacker who charges for closed source AI tools which work in hosted environments only. Yea, right.

I find that baffling. Why not just write the Elixir yourself?

I had this experience too. Though most of my issues were with my model not necessarily with Elixir itself so much as understanding the Phoenix model, state, and CLI. Maybe even differences in versions? Wasn't always clear.

claude 4 sonnet as the main driver atm, and a mix of smaller models depending on the scenario

Based on the blog post, Phoenix.new uses Claude 3 Opus as its underlying model, which explains its strong performance with Elixir/Phoenix codebases.

1.8rc, which is going 1.8.0 momentarily

1.7 or 1.8, not 7 or 8

It's safe to say that if either Chris or I believed this to be anti worker, we wouldn't be working on it. He's spent the last 10+ years working on Phoenix specifically to improve the lives of the people doing the work.

My experience with software development is maybe different than yours. There's a massive amount of not-yet-built software that can improve peoples' lives, even in teeny tiny ways. Like 99.999% of what should exist, doesn't.

Building things faster with LLMs makes me more capable. It (so far) has not taken work away from the people I work with. It has made them more capable. We can all build better tools, and faster than we did 12 months ago.

Automation is disruptive to peoples' lives. I get that. It decreases the value of some hard earned skills. Developer automation, in my life at least, has also increased the value of other peoples' skills. I don't believe it's anti worker to build more tools for builders.

You can think of it as just automating the boring tedious stuff so us humans can focus on the harder problems like strategy, direction, design, GTM, etc.

The days are numbered where humans are sitting typing out code themselves.

It's akin to the numbered days of type writer secretaries of the 20th century.

Most tech isn't "Anti worker". What determines pro/anti worker are laws and government policies that reciprocate with the cultural norms we adopt. At the moment, money in U.S. politics is the most anti-worker phenomena I can think of. The ultra wealthy have a monopoly on the incentives that create policy and how our lives are ordered. The only power working people seem to have is the ability to impose consequences via rogue guerilla acts of protest and violence (Luigi Mangion) . Hopefully, AI is a Frankenstein monster the public learns to wield to facilitate more of these "consequences" and upend the monopoly the super wealthy have on policy incentives and change the way politics is funded for good. It's a new world and a Hawaiian or New Zealand doomsday bunker isn't going make a difference.

The same logic that would lead one to believe that AI is anti-worker should also lead one to believe that software as a whole is anti-worker.

Do you believe making things easier and more accessible is bad for workers? I don't think it inherently is or isn't, it just depends on who benefits from the increased efficiency. I think that's more of a problem with your economic system, or wealth distribution.

Overall I think we would all be happier if efficient machines take away the drudgery of our daily work and allow us to focus on things that really matter to us. . . as long as our basic needs are met.

Maybe you mean the "My AI Skeptic Friends Are All Nuts" blog post on fly.io?

Where they have this nugget about plagiarism:

> But if you’re a software developer playing this card? Cut me a little slack as I ask you to shove this concern up your ass. No profession has demonstrated more contempt for intellectual property.

So I guess if you have concerns about them using any code you upload using this tool you can shove it up your ass.

Because of the amount of Python and JS in the wild is much more than the amount of Elixir code, so the LLMs have much more data to base their answers on.

Meanwhile I am a happy user of :ex_aws or :req_s3 which has done everything I need it to do. Object ops, iam policies, etc. A dependable S3 client has been there for years. The elixir core team doesn't need to maintain it. ReqS3 is one of my favorite things to use: https://hexdocs.pm/req_s3/readme.html

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.

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.

But there's two actively non-official maintained libs.

Not sure what you're talking about..