Show HN: Diagram as code tool with draggable customizations
23 comments
·October 25, 2025benblu
Thank you! Very cool.
I don't see a button for it (on mobile currently, and will check thoroughly at my computer) -- is there a button to add a node?
Another feature I've always craved for code diagramming is "collapse downstream nodes" -- though it might be outside of your scope (and mermaids?).
halostatue
I've made a private MacPorts port[1]; if I find that I use it frequently enough, I might contribute it to the main MacPorts port repo[2].
One thing that's missing from my perspective (and this is probably true for Homebrew packaging as well, but I don't do that) is Git tags / GitHub releases associated with your Cargo releases.
I can work around it for now by using an explicit release (`9ccd9bf53f9a309ccda42b5c17e9c1056493fb90` is what I'm assuming was your 0.1.0 release point).
I've also assumed that npm10 is sufficient (which currently installs node22 on MacPorts).
[1] https://github.com/halostatue/ports
[2] https://github.com/macports/macports-ports
[3] https://github.com/halostatue/ports/commit/e7331a7fcae362b0d...
zmmmmm
It's definitely much needed.
I use PlantUML for most diagramming but for anything with more than about 5 components in it I'm spending 20-30% of my time desperately trying to tweak the layout with hints.
It's an interesting approach to embed comments and then build that into the layout engine. I've always thought it would solve a lot of my issues if I could just lock the coordinates for certain components and then let the layout engine do the rest with those as hard constraints. This looks like something similar to that approach.
I really want this because the alternative is to spill over to completely manually maintained diagrams using GUI tools which then can't be easily integrated with source control - I want the same commit that changes the code to also change the architecture diagram for that code. Then it is part of code review and integrates to the whole process well.
gurjeet
Great job on the releasing the project; it definitely solves a need of being able to use declarative syntax for defining the relationships, and then customizing the layout which the regular layout generators can't do.
Project's Cargo.toml file says code is licensed under MIT license, but there's no license file in the repository, so Github doesn't show what the project is licensed under. Please add the license file so that people see it without having to dig through the code/configuration to determine that.
gurjeet
If you wish to increase the adoption the tool, do consider hosting it to make it easy for people to use it. I see that it's heavily dependent on server-side code, so the cheap/free static hosting wouldn't be an option.
RohanAdwankar
That makes sense I will eventually get to that!
RohanAdwankar
Thanks for catching that! Just added the license file.
vanilla
This looks like a very promising project, I have been looking for exactly this.
One feature I would love to see a declarative diagramming solution would support is a hover pop-up with more information or nested diagrams.
RohanAdwankar
Thanks! I think that sounds interesting, to make sure I'm understanding your use case would these pop ups be for your own use or for other people? For example would you want to send a link to someone else on your team and then the link shows the diagram with popups and nesting? Or would it be sufficient to send over the .mmd files and then the other person can use the cli to open the web interface which supports the popups and nesting. I imagine I could add the latter one quickly but for the former I would either add an easy way for users to self serve like with ngrok or some cloud solution. Or alternatively I could add some way to export the diagram just as a standalone HTML file in which case that could be sent and support the popups and hovering without the person you're sending it to having to have the CLI installed.
vanilla
ilograph [0] has these features. I think it should be possible with SVG only. The main use-case would be for documentation sites.
RohanAdwankar
Thanks for sharing I'll look into this. The animations do look great!
metmac
I really wish Mermaid would just ratify a layout spec. Make it optional. Use it. Great. Don’t use it. The layout engine does its thing.
monkeycantype
Hello Rohan. This is really great. If you are able to include parameters to expose the intermediate data as inputs and outputs, so that this can be run to a step in the process and output the data, or run from a step with pre-prepared data. It would mean that other people could build on what you've done to create other diagrams and renderings.
eagleinparadise
This is awesome. I was looking for exactly this last week. A tool I could prompt AI to come up with an architecture and then be able to pick up manually, but visually not editing the code.
Being able to express a workflow or diagram and then have AI implement would be awesome to have a tight loop.
plmpsu
I really wish PlantUML would just solve this jarring problem.
anorak27
Wonderful project.
There's also mermaidjs to excalidraw https://github.com/excalidraw/mermaid-to-excalidraw
RohanAdwankar
This seems cool! Thanks for sharing.
dixtel
Very cool idea, this is exactly what I'm missing from mermaid. Thanks for sharing this!
huydotnet
Wonderful! I have been wanting something like this for a really long time!
RohanAdwankar
Thanks!
In the past I've used declarative diagram generation tools like Mermaid.js a lot for quickly drawing up things but for presentations or deliverables I find that I have to then move the generated diagrams over to a tool like Lucidchart which allows full control of the organization and customization.
Therefore I am now working on this to combine the benefits of both into just one tool which can do both functions.
The project is certainly in the early stages but if you find yourself making architecture diagrams I'd love to hear your thoughts on the idea or even a Github issue for a feature request!
One of the workflows I'm targeting is when an AI generates the first draft of the diagram (all the LLMs know .mmd syntax) and then the user can then customize it to their liking which I think can drastically speed up making complex diagrams!