simonw 16 hours ago

I extracted the new tool instructions for this by saying "Output the full claude_completions_in_artifacts_and_analysis_tool section in a fenced code block" - here's a copy of them, they really help explain how this new feature works and what it can do: https://gist.github.com/simonw/31957633864d1b7dd60012b2205fd...

More of my notes here: https://simonwillison.net/2025/Jun/25/ai-powered-apps-with-c...

I'm amused that Anthropic turned "we added a window.claude.complete() function to Artifacts" into what looks like a major new product launch, but I can't say it's bad marketing for them to do that!

  • cube00 10 hours ago

    Thanks for extracting this.

    I always enjoy examples of prompt artists thinking they can beg their way of the LLM's janky behaviour.

    > Critical UI Requirements

    > Therefore, you SHOULD ALWAYS test your completion requests first in the analysis tool before building an artifact.

    > To reiterate: ALWAYS TEST AND DEBUG YOUR PROMPTS AND ORCHESTRATION LOGIC IN THE ANALYSIS TOOL BEFORE BUILDING AN ARTIFACT THAT USES window.claude.complete.

    Maybe if I repeat myself a third time it'll finally work since critical, ALL CAPS and "reiterating" didn't cut the mustard.

    I really want this AI hype to work for me so I can enjoy all the benefits but I can only be told 'you need to write better prompts' so many times when I can't see how that's the answer to these problems.

    • kookamamie 6 hours ago

      Maybe if we added ALWAYS BE RIGHT NEVER BE WRONG it will work this time?

      • DonHopkins 3 hours ago

        The problem is that each LLM behaves totally differently in response to the exact same prompts. You can't just tell them all to be RIGHT and expect the same or even correct results everywhere everytime.

        For example, Grok will interpret "BE RIGHT" as an imperative command to inject White Supremacist Ideology and Holocaust Denial into dialogs about quantum physics and children's bedtime stories.

    • Edmond 8 hours ago

      We've learned this the hard way working with AI models, yelling at the models just doesn't work:)

      I would think someone working for Anthropic would be quite aware of this too.

      Either fix the prompt until it behaves consistently, or add conventional logic to ensure desired orchestration.

jonplackett 18 hours ago

I used to love to make silly websites or apps with new technologies. Been doing it since flash. I have a pretty decent hit rate! It’s not unusually to get half a million or so people try one of them.

But with AI that model is just totally broken because the running cost is so high.

If I have half a million people come play my silly AI game that I have no wish to monetise - I am gonna be POOR very fast.

Log in with [insert ai vendor here] is something I’ve been hoping would happen for a while.

  • gavmor 16 hours ago

    "Log in With Google" to use Drive storage has long been a thing. Maybe proxying Gemini usage isn't too far off.

    • dcl 13 hours ago

      "Bring your own AI" or "Provide your AI API access key" will probably be coming to a lot of services/apps that we want 'our' AI's to interact with.

      I can see this also bringing strongly tiered AI's, there will be commodity/free AI's a and expensive ones for rich people/power users.

      • gavmor 12 hours ago

        I just hope I live to see the day personal agents are empowered to make ad hoc use of paid services on our behalf—via eg AITP (Agent Interaction & Transaction Protocol), which is specifically designed to enable autonomous, secure communication, negotiation, and value exchange between agents across trust boundaries. AITP includes explicit capabilities for "Payments" (AITP-01) and "Data Request" (AITP-03), allowing structured sharing of sensitive information like addresses and passwords that can be programmatically verified and executed.

        Similarly, the Coral Protocol aims to be an open and decentralized infrastructure for "The Internet of Agents," with "built-in economic transactions" at its core. This means agents can be compensated for their contributions via on-chain micropayments

        Oh, damn, no, that sounds like an expense-tracking nightmare. Budgeting becomes the principal executive input.

        • nsriv 7 hours ago

          Last line of your comment is what I was thinking the entire time. Another layer of abstraction between our minds and our wallets.

      • cube00 10 hours ago

        > "Provide your AI API access key" will probably be coming to a lot of services/apps that we want 'our' AI's to interact with.

        Considering provide your own API key is banned by a number of larger players (Reddit, Google Maps) to stop large numbers of users cashing in on the free/cheap low usage tiers I'd expect AI vendors would enforce the same rules soon once all this free VC hype funding dries up.

      • kgdiem 12 hours ago

        Snowflake does revenue sharing, it’s possible that AI providers can start doing that too.

  • nsoonhui 6 hours ago

    >> If I have half a million people come play my silly AI game that I have no wish to monetise - I am gonna be POOR very fast.

    But the article says:

      When someone uses your Claude-powered app:
    
      They authenticate with their existing Claude account
      Their API usage counts against their subscription, not yours
      You pay nothing for their usage
      No one needs to manage API keys
    
    So how would that impact you?
    • Pmop 6 hours ago

      Yep. Meanwhile I’m trying to figure out how can I make something that people would want to pay for, and how can I charge them, if they’re going to interact directly with Claude and burn their own quota.

      • wwdx 4 hours ago

        anthro needs to let the creator charge % on top of their usage quota or give points/money to the creator to fix up the incentives here

        • cranium 4 hours ago

          That's a really good idea! That would handle micropayments that nobody would even bother with (to pay, to process, to receive, ...).

          Could even have users select the payment %age or have it set by the contract tier between the app creator and the user (10% for simple user, 20% for pro access with other features, 40% enterprise,...).

    • archerx 5 hours ago

      That's still no good. The only real way it could work is by having models running locally with WASM.

  • mbm 17 hours ago

    Agreed, it's an interesting model. I wonder what the approval ui looks like for the app end-user? Is it super clear to them that they're financially responsible for their usage?

    • jonplackett 17 hours ago

      Yeah I wonder how that actually works - because I would guess people are logging in with their consumer login not an api login, so they’re not really even in the mindset of limits and cost per token.

      • mbm 16 hours ago

        Precisely. You click on a claude link, and suddenly it's, "You are now financially responsible for your actions from here on..." I'm sure they've spent a lot of time thinking through the ui/ux of this.

        • ameliaquining 13 hours ago

          Users of Claude-hosted apps can't thereby incur financial liability, because it counts against the usage limit of their consumer Claude plan, which either is free or has a fixed monthly subscription price. The worst that can happen is that they run out of quota and can't use Claude anymore until it resets, which happens every day on free plans and every five hours on paid ones. In no case is usage attributed to an API key with metered pricing.

          • mbm 12 hours ago

            Ah true. So the push becomes even stronger for people to upgrade to the max plans, when several of the "apps" they're using are consuming their allocated Claude tokens. Brilliant.

  • jerpint 16 hours ago

    This is seriously lacking but I think things like jailbreaks and malicious prompts make it a bit too brittle for now

    • jonplackett 15 hours ago

      The thing is though, it doesn’t need to have access to your personal info in the context, so it cant leak anything. And they are obviously used to people talking all sorts of jailbreak shit to their chatbot - so it isn’t really much worse than that.

      Also I reckon the cost of running a text chatbot is basically peanuts now (that is, for a giant tech company with piles of hard cash to burn to keep the server farm warm)

amelius 3 hours ago

Remember, folks: don't build your castle in someone else's kingdom.

  • owebmaster 12 minutes ago

    That's not a great advice, actually. Don't build just one castle and extract all value from the kingdom to your castles outside of it.

    • amelius 5 minutes ago

      That's ... a lot of work. If you have that kind of resources you might as well play an entirely different game.

WXLCKNO 19 hours ago

The tiniest step towards a future where AI eats all apps.

No persistent storage and other limitations make it just a toy for now but we can imagine how people will just create their own Todo apps, gym logging apps and whatever other simple thing.

no external API access currently but when that's available or app users can communicate with other app users, some virality is possible for people who make the best tiny apps.

  • meistertigran 17 hours ago

    Actually implementing persistent storage for simple apps isn't that hard, especially for a big corp. Personally, I was using LLMs coding capabilities to create custom single-file HTML apps, that would work offline with localStorage. It's not that there aren't good options out there, but you can't really customize them to work exactly how you want. Also it takes like half an hours to get what you want.

    The only downside was not being able to access the apps from other devices, so I ended up creating a tool to make them online accessible and sync the data, while using the same localStorage API. It's actually pretty neat.

  • amelius 4 hours ago

    > The tiniest step towards a future where AI eats all apps.

    I wouldn't be surprised if, at some point, we'll see nVidia starting an "AI AppStore" and charging Anthropic 30%.

  • sharemywin 17 hours ago

    I've used the interface in chatgpt to click on a button and talk back and forth with an AI and I could see this being pretty good interface for alot of "apps"

    weather, todo list, shopping list, research tasks, email someone, summarize email, get latest customized news, RSS feed summary, track health stats, etc.

    • SonomaSays 17 hours ago

      You could have a hybrid business model:

      Build a thing that does a complex thing elegantly (Some Deep Research Task) that is non trivial for others to setup, but many people want it.

      Charge a direct access in a traditional sense [$5 per project] -- but then have the Customer link their API to the execution cost - so they basically are paying for:

      "Go here and pay HN $5 to output this TASK, charge my API to get_it_done" This could be a seriously powerful tool for the Digital Consulting Services industry.

      (I mean that is what its model for)

      So this begs the question, will Anthropic be building in a payments mechanism for such to happen?

  • headcanon 18 hours ago

    One thing I've learned is that no matter how easy it is to create stuff, most users will still favor the one-click app install, even if they don't get full control over the workflow.

    With that said, I'm sure there are a lot of power users who are loving the lower barrier to creation

    • wombatpm 9 hours ago

      You can build lots of cool stuff. Getting corporate IT to allow api access is like pulling teeth. We have Outlook and Teams, which have APIs that can do things. But no one has the ability to access them. So much for automating your workflows.

      Reminds me of Lotus Notes back in the day. It could do anything and had great potential, but there were only 3 developers who had access. In a company of 50k employees.

  • handfuloflight 19 hours ago

    > No persistent storage

    What stops you from wiring it up to your endpoints that handle that?

    • js4ever 19 hours ago

      Current limitations: No external API calls (yet), No persistent storage

  • revskill 3 hours ago

    Human being is funny. They should just sit at home and doing nothing instead.

  • throwaway7783 16 hours ago

    Matter of time. It is trivial to overcome the current limitations.

  • jofla_net 19 hours ago

    Great, %1 of the competition that we have today. Cant wait to see a the wasteland when all apps will effectively be from a couple companies. /s

alach11 15 hours ago

This is starting to encroach on Lovable, right? I do suspect the effect of these "vibe coded" apps on the SaaS market will be smaller than expected. Heavier-featured apps will have all sorts of functionality and polish a user won't even think to ask Claude to build. And the amount of effort to describe everything you need an app to do is higher than it seems.

Instead, I think this is going to open a new paradigm with an immense long-tail of hyper-niche fit-for-purpose business applications. There's so much small-scale work that happens in corporations that isn't common enough to be worth building a product to solve. But it's still a big time-saving to the departments/users if they can improve the process with a vibe-coded app!

  • socketcluster 13 hours ago

    Yes and it may open the door for new platforms with pure backend (BaaS) focus. With AI hallucinations, letting AI write backend code is not feasible due to security implications. Access controls still require a control panel which can be easily audited.

    The frontend, however, is a completely different story.

    It reminds me of a saying from one of my ex-colleagues "Frontend development is like building a house of cards. If it falls, nobody gets hurt. On the other hand, backend development is like building a house out of wine glasses."

    AI and frontends are a natural fit, there is way more tolerance for brittleness 'move fast break things' on the frontend as the consequences of bugs are far less severe.

    • moron4hire 4 hours ago

      I am begging you to please discard this incredibly naive viewpoint before you get someone hurt. Please go learn more about secure development practices.

  • awb 15 hours ago

    Hyper-niche products come with some inherent risk that it’s not always profitable to maintain or develop them long-term.

    With a mass market product leader you’re sacrificing a bit of customization for long-term stability.

reidbarber 19 hours ago

The big feature here is that the shared artifacts can use the Claude API themselves (where usage is tied to the logged-in users of your shared artifact).

huevosabio 16 hours ago

I love this business model idea, but I think the model providers are the wrong company to do it. It should be something like OpenRouter.

As a developer, you probably want to access to the right models for your app rather than being locked in.

4b11b4 8 hours ago

This is interesting.

Have jokingly been thinking: "If you can't do, teach."

You can't just pour A1 on education and expect something magical to happen. But, I do think there's some potential for tutors/teachers on the fly to create some interactive learning tools to go along with whatever they are topic they are exploring with someone in the moment.

Just recently: "Make me an interactive artifact for teaching 2s complement where it shows the sign and unsigned version side by side you can click on the binary digits to toggle them between 1 and 0". A few tweaks to layout while I'm also explaining on pen and paper. Then I brought it out and it certainly helped things click

And I was thinking that these kind of mini lessons could be shared and forked and tweaked. Now you have a language model available by default...

isoprophlex 19 hours ago

Is this the end of - or at least a significant challenge to - SaaS?

Why buy into saas tooling if you can just slap something together - that you fully own - with something like this?

  • headcanon 18 hours ago

    Challenge, yes, but I wouldn't go far to say "end of".

    B2C SaaS will have more challenge the easier it gets to create things, but consumers have always been fickle anyway.

    I'd say B2B SaaS is mostly safe, partially because they want the support and don't want to have to maintain it.

    Today we have open-source versions of a lot of SaaS products, but the proprietary ones are still in business, mostly for that reason IME.

    • alvah 13 hours ago

      I think B2 (small) B SaaS is also in trouble pretty much now. Enterprise is a different thing though, the barriers to entry are not just building and maintaining the software.

      • msy 10 hours ago

        I don't buy this. Real small business have enough problems that trying to vibe code a Xero replacement isn't really high on the todo list.

        • NitpickLawyer 6 hours ago

          Small businesses also use a spreadsheet e-mailed from person to person. A vibe-coded x_table or x_base powered app would get them 80% there with minimal cost. I'd put it in a "it depends" category of things that might or might not happen in the near future.

    • calvinmorrison 17 hours ago

      you can swing it anyway you want - another reason we use spreadsheets, or another reason we don't use airtable, or CRM #37....

      all systems require support and upkeep... nobody wants to do it.

  • sealeck 18 hours ago

    - Compliance

    - Thing should work reliably (and you want someone else to be responsible for fixing it if it doesn't)

    - Security

    - Most SaaS is sufficiently complex that an LLM cannot implement it

    • samsolomon 17 hours ago

      Enterprise SaaS are business processes that lean extremely heavily on software. Some of that could be amended by AI, but it's much harder for me to see that getting wholesale replaced the same way many consumer apps could be.

    • jag729 17 hours ago

      In the limit, though, are these things real roadblocks to app builders replacing SaaS? Paying for reliability/support seems like the only real remaining advantage of SaaS if codegen models get 3-5x better, and even then the bar is the reliability of SaaS apps right now (which in a lot of cases is not that high).

      Could imagine a single universal app builder just charging a platform fee for support, or some business model along those lines. (Again, in the limit, I'm not sure that support would be too necessary)

    • throwacct 18 hours ago

      This x100. B2B is a different monster altogether.

  • giancarlostoro 18 hours ago

    When you have a service outage you think the AI will be able to troubleshoot the entire system and resolve the issues?

    • jkcorrea 18 hours ago

      if scaling laws and context windows continue, why not?

      • SonomaSays 17 hours ago

        There is coming a very_soon_time whereby one will have to ensure all the routes and failure_modes for the AIs plumbing are functional.

        What if the outage is specifically that AI_agent cant reach [thing]?

        • falcor84 17 hours ago

          > What if the outage is specifically that AI_agent cant reach [thing]?

          We already saw some examples of this in Anthropic's safety papers - the AI will reach out to the human to get help with that - essentially using a human as an API/tool.

  • nikcub 16 hours ago

    maybe not b2b saas since that has always been around service contracts - but a lot of those internal processes that currently run in excel are prime for AI mini-app replacement.

    this is delivering what no-code promised us.

levocardia 18 hours ago

This is cool...but what I really want is (1) Claude and I develop a cool app, (2) I give Claude a virtual credit card number with a spend limit, (3) Claude deploys it to whatever service they think works best (Railway, Vercel, ...) and points a domain name to that hosting service.

  • ethan_smith 6 hours ago

    The third-party deployment approach would require Claude to maintain integrations with dozens of services, handle authentication flows, and manage infrastructure decisions - significantly more complex than serving static content within their own ecosystem.

  • AtheistOfFail 17 hours ago

    Noone in cloud wants spend limits, everyone wants limitless billing.

kiru_io 7 hours ago

This feels like a indirect response to what Andrej Karpathy said in his last presentation, about how it took him barely any time to create the project, but spent a few days to figure out how to deploy the project.

asdev 18 hours ago

>They authenticate with their existing Claude account

Only works if both app producer and user are in the Claude ecosystem

bionhoward 13 hours ago

What’s this? Another category of companies forced to compete with Anthropic? It’s almost like it’s impossible to use Claude without breaking the Anthropic legal terms…

  • ameliaquining 13 hours ago

    I don't think Anthropic has been going after wrappers on legal grounds? They declined to renew a bespoke capacity agreement with Windsurf but that seems different.

ru552 19 hours ago

Is this much different from the custom GPTs that OpenAI pushed a year or two ago?

  • elpakal 17 hours ago

    Same question, but I'm less clear on how we devs get paid here.

    Still hoping someone builds the App Store for custom GPTs where we don't have to worry about payment and user infrastructure. Happy giving up a percentage for that butnot30percentguys.

    • ffsm8 17 hours ago

      In this case the code in question is actually running on the service providers metal, essentially PaaS.

      I wouldn't feel comfortable comparing that to the 30% i-wonder-who takes for providing a store to download packages that then run on the edge.

      (And fwiw, all of them should be able to take any percentage they want. It's only an issue if there is no other option)

  • ianbicking 15 hours ago

    It feels like what Custom GPTs should have been. Custom GPTs are barely able to do anything interesting beyond an initial prompt, there's no ability to modify the core user experience. The ability to run code and have it do subrequests makes this actually interesting.

  • handfuloflight 19 hours ago

    All things being equal, Claude is just better.

  • owebmaster 9 hours ago

    No. Same idea. OpenAI execution failed, let's see anthropic attempt.

4b11b4 8 hours ago

Would be cool if on a Pro plan Anthropic allowed an occasional session for an unauth'd user at at less frequent or restricted level

It might apply to your own rate limit...

nico 19 hours ago

This is a really cool feature and it’s big competition for services like Lovable, Bolt, v0

Seems like AI-assisted coding space is splitting in 2:

1) tools and services that aim mostly at prototyping and are close to no-code; most useful for users like PMs or very early stage entrepreneurs who just need to have something to show/share

2) professional tools that target “serious” developers who are already working on bigger/more complex code bases

Interesting that Claude is going after both. 1) with this new feature, and 2) with pretty much all their other services

throwaway7783 16 hours ago

This is the future of applications. Still not sure if model providers are the ones to do it. I think of LLM as infrastructure and I can build apps on it in a "general" way. Not the bespoke wrapper apps that are proliferating today, but LLM as a native interface to build(and use the app).

ukuina 13 hours ago

Is monetization coming soon?

i.e., toggle a "Commercial" switch and users are charged API cost plus 10-30% with the creator getting a third of that?

Also, the switch would disable "See, fork, and customize any artifact"

  • owebmaster 9 hours ago

    This is the missing piece and a real moat with the network effect. The new Google.

riskable 17 hours ago

If only this worked with image generation! There's vastly more applications for this kind of thing in that space. They're more fun too :)

tempodox 18 hours ago

This is the logical next step to code-generating LLMs, it makes perfect sense. I'm curious to see how useful it will actually be, and whether it will be worth the costs.

Oras 17 hours ago

Isn’t that what ChatGPT plugins tried to do? I don’t see the point.

If I create something, others can can use with their account, what’s my value?

  • cryptoz 17 hours ago

    I'm building something like this. The value to you would be that you could earn a margin on the token costs. That is, the end user is charged 2x the token cost of the API call. The API provider earns the base cost, the platform owner earns 20% of the remaining cost, and the webapp creator earns 80% of the remaining price.

    So for an API call that costs $0.50, the end user is charged $1; and from that AI API earns $0.50, the webapp creator earns $0.40 and the host earns $0.10.

    I'm trying this out with https://codeplusequalsai.com right now but it's not clear to me yet that it will take off!

    But clearly, the value to you should be that you could earn $ based on the token usage from end-users.

    • onel 6 hours ago

      I checked your website I it's an interesting idea. I think you need some additional copy though, because just landing on your homepage you don't really understand what it does. More exactly I don't know what to use it for. Your comment and GP's coming together gave me a better idea.

      What's your target audience? developers?

      • cryptoz 4 hours ago

        Fantastic feedback, my gosh, thank you. Yes the home content doesn’t do a good job of explaining what it is. Honestly that’s because a lot of the ideas I typed here are pretty fresh, and my ‘marketplace’ is only implemented on prod as a prototype. I do see the the mismatch in copy and the real utility.

        I’ll work on positioning and update the copy to keep in sync with my vision …

        And yeah, my target audience is developers, specifically those with not a lot of time but with a lot of ideas.

        Gosh thanks again, that’s super excellent feedback.

syedumaircodes 18 hours ago

Is this like roblox for AI? I'm new to this (HN and all) so I don't know much about it.

fake-name 9 hours ago

How do you host a app with Claude. Did they release the weights?

jongjong 15 hours ago

Nice. This is the feature I've been waiting for to plug my low-code backend into.

I was too lazy to build a whole frontend like Lovable.

muskmusk 18 hours ago

"everything evolves until it becomes an operating system"

  • falcor84 17 hours ago

    Or at least until it contains an "ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp"

owebmaster 17 hours ago

This will be a flop and they will buy some startup doing it much better. Anthropic (and OpenAI and Google and meta) just sucks with UX.

Also I'm expecting some revenue share if I'm bringing users to spend money with Anthropic API.

socketcluster 14 hours ago

Could this be the feature which finally unlocks the potential of my low-code Backend as a Service? https://saasufy.com/

Looking for people to try it out. You just need to create an account on saasufy.com (with GitHub) then paste (or attach) the README.md file from our GitHub https://github.com/Saasufy/saasufy-components/blob/main/READ... inside Claude, telling it what your Saasufy service URL is (shown on saasufy.com dashboard after deployment) then deploy directly from Claude.

This is a good approach. Developers can interact with Claude directly while BaaS platforms like Saasufy can host the backend and data in a secure way. This is ideal because the frontend can tolerate some hallucinations/brittleness, but the backend cannot. This approach could finally support production-ready apps, not just prototypes.