[HN Gopher] Show HN: ChartDB Agent - Cursor for DB schema design
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Show HN: ChartDB Agent - Cursor for DB schema design
Last year we launched ChartDB OSS
(https://news.ycombinator.com/item?id=44972238) - an open-source
tool that generates ER diagrams from your database (via
query/sql/dbml) without needing direct DB access. Now we're
launching the ChartDB Agent. It helps you design databases from
scratch or make schema changes with natural language. You can: -
Generate schemas by simply describing them in plain English -
Brainstorm new tables, columns, and relationships with AI -
Iterate visually in a diagram (ERD) - Deterministically export SQL
script Try it out here - https://chartdb.io/ai - no signup
required. Or sign up and use it on your own database Would love
to get your feedback :)
Author : guyb3
Score : 105 points
Date : 2025-10-01 13:38 UTC (9 hours ago)
(HTM) web link (app.chartdb.io)
(TXT) w3m dump (app.chartdb.io)
| quentindanjou wrote:
| This is really cool! Would love to use that for quite a bit of
| prototyping on some personal projects!
|
| Only thing I kinda dislike is the low readability of the
| connection because of that border around the table of the same
| color as the connection lines (I think things would look cleaner
| without it)
| apwell23 wrote:
| what makes this an "agent"
| bopbopbop7 wrote:
| The for loop I wrote today is an Agent, at least that's what
| I'm telling the investors.
| uxhacker wrote:
| And when will it do class designs? Maybe this would solve many an
| AI coding issue.
| OsrsNeedsf2P wrote:
| What can this do that Claude Code cannot? Is it just the ERD?
| pella wrote:
| "an open-source tool" --> https://github.com/chartdb/chartdb (
| AGPL-3.0 license )
|
| prompts:
|
| https://github.com/chartdb/chartdb/blob/c3c646bf7cbb1328f4b2...
| evanelias wrote:
| At quick glance I already see several things in that prompt are
| completely incorrect. For example: MariaDB has natively
| supported sequences for quite some time; for decades all
| versions of MySQL/MariaDB support "bool" or "boolean" as an
| alias; the timestamp default value advice is wrong as any
| arbitrary expression can be used; etc.
|
| These are all easily testable in Docker containers. There's a
| concerning lack of attention to detail here, or perhaps the
| prompt itself was also created using AI and it bakes in
| hallucinations from the get-go.
|
| As for the AGPL: in ChartDB's previous Show HN (only 6 weeks
| ago), I asked how they were running an enhanced paid SaaS when
| they had so many external contributions prior to adopting a
| CLA, and I did not receive a response [1].
|
| [1] https://news.ycombinator.com/item?id=44972986
| politician wrote:
| > There's a concerning lack of attention to detail here.
|
| I choose to believe that it's a brilliant feint. The author
| will run all these comments back into their LLM to generate
| fixes for all of these issues.
| daxfohl wrote:
| Wow, how can you afford offering free AI on the homepage for an
| OSS project? I can barely afford AI APIs even for my own personal
| use. Seems like it would drive costs through the roof.
| nacs wrote:
| Maybe they value the training data?
| trjordan wrote:
| My conversation
|
| "Design a schema like Calendly" --> Did it
|
| "OK let's scale this to 100m users" --> Tells me how it would. No
| schema change.
|
| "Did you update the schema?" --> Updates the schema, tells me
| what it did.
|
| We've been running into this EXACT failure mode with current
| models, and it's so irritating. Our agent plans migrations, so
| it's code-adjacent, but the output is a structured plan
| (basically: tasks, which are prompt + regex. What to do; where to
| do it.)
|
| The agent really wants to talk to you about it. Claude wants to
| write code about it. None of the models want to communicate with
| the user primarily through tool use, even when (as I'm sure
| ChartDB is) HEAVILY prompted to do so.
|
| I think there's still a lot of value there, but it's a bummer
| that we as users are going to have to remind all LLMs for a
| little bit to do keep using their tools beyond the 1st prompt.
| IChooseY0u wrote:
| isnt this what the agents are for, you assign them jobs to make
| changes then evaluate those changes. there is a necessary
| orchestration piece and maybe even a triage role to sort
| through things to do and errors to fix
| skeeter2020 wrote:
| I asked it to abstract a event-specific table to a GP "events"
| table which it did, but kept the specific table. I asked it to
| delete that table and it said it did, but did not. I got stuck
| in a loop asking it to remove the table that the LLM insisted
| was not part of the schema, but was present in the diagram.
|
| It was easier to close the tab than fire a human, but other
| than that not a great experience.
| sergiotapia wrote:
| to save tokens you should have a pre-baked replay play when you
| click those buttons i just want to see the end result and the
| process sped up since i dont know what the service does. good
| luck!
| thomask1995 wrote:
| This is super cool!
|
| Have you thought about making a tool to help preview/dry run
| migrations?
|
| I feel that's something I would want a ton of confidence in if an
| LLM is making migration scripts.
|
| Especially if it's doing scary stuff like breaking up a table.
| whilenot-dev wrote:
| How do you expect an LLM to help here? Can't you just use
| OverlayFS on the database volume, or a backup thereof, and run
| the migration against that?
| ako wrote:
| In my experience most AI coding tools can work with databases,
| especially if you give it an MCP tool to connect to your
| (development) database. It will generate mermaid er-diagrams by
| reading from your database catalog, it will generate SQL to
| create tables, views, etc. It will generate queries, validate
| them and return data. It will optimize your query performance by
| running the query, running explain plan, looking into
| pg_stat_statements (or whatevery your database uses), and propose
| SQL optimization, indexes to be created. It will also create demo
| data with realistic use cases like black friday or back to school
| discounts for prices, etc.
|
| A SQL MCP + mermaid is all you need.
|
| Btw, it can also do an awesome job turning query plans into
| readable mermaid flow diagrams, adding details to the chart,
| using color to highlight bottlenecks.
| debarshri wrote:
| Agreed
| EcommerceFlow wrote:
| Super cool and useful, thank you. Was just doing some database
| mapping so this is perfect!
| asdev wrote:
| I can prompt an LLM to make a mermaid diagram and iterate on it.
| Why do I need "ChartDB"?
| Aperocky wrote:
| I'd gonna go one step further and argue that you don't even
| need mermaid for creating DB schemas.. direct chat works fairly
| well for reference.
| ssantoshp wrote:
| always used direct chat with an ORM & can't complain
| not--felix wrote:
| The idea is great but it feels like it uses a dumb model
| daxfohl wrote:
| It'd be nice if it also included the queries for each use case,
| and had a better understanding of sharding. As is, I gave it a
| bunch of requirements, it created some tables. Was it sufficient?
| No idea, it didn't say what the query was for each requirement.
| Would it scale? Again, no idea without the queries. (But
| actually, no, it wouldn't have scaled; some requirements were
| impossible without cross-shard scans).
| encoderer wrote:
| 99% of apps never need to shard data. Probably closer to 99.9%
| if they are single tenant.
| daxfohl wrote:
| That seems off in my experience, but maybe it's different in
| different industries.
|
| Either way, working around sharding and scale seems like a
| place where a good AI could help provide recommendations and
| tradeoffs, so it's disappointing that the model doesn't seem
| to deal with it well. For basic relational schema design, I
| don't see much benefit of having AI.
| dorianmariecom wrote:
| reddit has only two tables ;)
| tdhz77 wrote:
| The visual is really nice. I can appreciate this tool, but once
| it's in my database it's for the human to manage and update. Do I
| go back to using this tool? How can this help? I don't want any
| tool to read data like mcp can. Read table names, sure.
| kumarm wrote:
| The UI presentation of Schema is really nice. Is there a
| javascript based UI for web that is used?
| Macuyiko wrote:
| On the homepage it says "Sinmple" above "Export SQL", fyi
| stronglikedan wrote:
| It seems very useful for people that haven't designed many
| databases (it follows good patterns), but I feel like I could
| build the ERD faster than I could build those detailed prompts
| (from the examples), and I would get the benefit of naming things
| my way.
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