Show HN: One prompt generates an app with its own database

Fun note: I tried opening this in two tabs, and indeed the poops were real-time!

Appreciate the kind words :). Looks like there's a lively conversation in there!

Huh, that's a lot of creativity from the LLM! I am always surprised by it.

I was curious how GPT-5 would do with your prompt. Here's what it got:

http://noble-orca-yq331e.manyminiapps.com/

It got something, but _much_ less creative then Claude in this instance.

> Can you say more about that? What kind of queries does it support? Sounds a bit like datomic or datascript. How do you tell the agent to use it?

Yes, we definitely take inspiration from datomic and datascript, as well as Tao (Facebook's DB). EAVs have a few good properties. First, it's more natural to do last-write-wins at the column level this way. Second, we get a real shot at creating a multi-tenant database.

With EAVs you can either query them with datalog, or use SQL CTEs. Fun fact, on Instant's backend, we use a datalog-like langauge as intermediary representation, which ends up converting to a SQL CTE.

Technically, you can make query on these as you can on a traditional SQL DB.

To interact with all this, users (and in proxy agents) use a graphql-like language, called InstaQL. It's like if GraphQL was represented as plain javascript objects.

Here's the system prompt, which shows these off:

https://gist.github.com/stopachka/a6b07e1e6daeb85fa7c9555d8f...

> Do you use an agent SDK or is it home grown?

It's about 260 lines of home-grown code. Here's a snippet of how it looks:

https://gist.github.com/stopachka/a38f00545d048661cf15a3cf4d...

Two interesting things there:

1. Since Instant is reactive, we use it to convey the stream to the client. This way all chats are "resumable" by default, even if the user refreshes the page.

2. To make sure Instant writes don't block the stream, we use a "natural" buffer approach. Basically tokens from the LLM buffer up during every save.

Oh, interesting! I just took a look.

I updated the system prompt a bit, here's a version of your app that's working with it:

https://brave-elm-7m6ar8.manyminiapps.com/

(The chat: https://www.manyminiapps.com/?c=1a5d3481-d2e2-414c-a7c3-4d0c...)

---

For the curious, the issue was that the LLM originally decided to write the query:

```

    const { data } = db.useQuery({
      worlds: {
        $: { order: { createdAt: 'desc' } },
        snapshots: {
          $: { order: { timestamp: 'desc' }, limit: 1 }
        }
      }
    });

But we don't support limits on subqueries yet.

We had a specific note in the system prompt warning the LLM to avoid this. Interestingly, _removing_ the warning fixed the issue. I guess it's kind of like telling someone to not think of a red elephant.

Nice! I liked it's creativity in there. Since it doesn't haven LLM to generate code, it just writes a basic boilerplate and inserts your prompt.

Ah, wish there was a way it had access to babel/runtime. [1]

[1] Though then the mini app builder inside the mini app builder would have a security vulernability, if the mini mini apps actually evaluated.

I got this with a very short and basic prompt, it lets the user track blood sugar and ketone levels.

It worked really well, and it was very fast, especially considering that it is on the front page of HN. Congrats, very cool project

Link to the app https://vital-crow-mmrs4s.manyminiapps.com/

Update 2: Claude seems to be back. We have the GPT 5 version ready, just in case now : )

And it works! https://www.manyminiapps.com/?c=da20213e-6832-4cd8-ac73-7669...

Albeit slowly.

Oo cool idea! We don't limit the input size, so you could add more context. I wonder if giving it some docs on Instant's presence [1] could help it do the right thing with Doom. Ideally movements should be ephemeral rather than stored in the DB, and the system prompt we have doesn't say too much about that.

[1] https://www.instantdb.com/docs/presence-and-topics.md

Oh that's weird. Would you mind sending over a few links of the apps you made?

Oof, sorry about that. Do you have a link? Curious to dive deeper

I would suggest sharing the app you built, and seeing what others come up with.

Technically you could use the apps for yourself too, though everything is public so be wary.

Clicking "make" takes me straight back to the first page.

Easy.

Step 2. Scale unicorn SaaS to $1B valuation

Step 3. Sell it, become rich, buy superyacht