FluidCAD – Parametric CAD with JavaScript
Hello HN users,This is a CAD by code project I have been working on on my free time for more than year now.I built it with 3 goals in mind:- It should be familiar to CAD designers who have used other programs. Same workflow, same terminology.- Reduce the mental effort required to create models as much as possible. This is achieved by: - Provide live rendering and visual guidance as you type. - Allow the user to reference existing edges/faces on the scene instead of having to calculate everything. - Provide interactive mouse helpers for features that are hard to write by code: Only 3 interactive modes for now: Edge trimming, Sketch region extrude, Bezier curve drawing. - Implicit coding whenever possible: e.g: There are sensible defaults for most parameters. The program will automatically fuse intersecting objects together so you do not have to worry about what object needs to be fused with what. - It should be reasonably fast: The scene objects are cached and only the updated objects are re-computed.I think I have achieved these goals to a good extent. The program is still in early stages and there are many features I want to add, rewrite but I think it is already usable for simple models.Update to add more details: This is based on Opencascade.js WASM binding. So you get all the good things that come with any brep kernel. Fillets, chamfers, step import and export...The scene is webview but the editing is in your local file. You use your own editor and the environment you are familiar with.One important feature that I think make this stand out among other code based cad software is the ability to transform features not just shapes. More here: https://fluidcad.io/docs/guides/patterns You can see it in action in the lantern example: https://fluidcad.io/docs/tutorials/lantern
FL score
out of 100
Verdict
medium confidence
Competition
6
competitors found, emerging market
Trend
No signal yet
A parametric CAD tool leveraging JavaScript for developers, offering an intuitive, interactive workflow that bridges the gap between traditional CAD and code-based design.
The pain
The gap
Build angle
Strengths
- Addresses very specific and severe pain points with existing code-CAD solutions.
- Clear competitive differentiation with a unique blend of code-first and visual/interactive CAD features.
- Market is emerging and growing, with no funded competitors, providing a strong opportunity for a niche player.
- The creator demonstrates deep domain knowledge and commitment with a year-long MVP development.
- Built on OpenCascade.js, offering powerful B-Rep capabilities.
Risks
- High build complexity and ongoing maintenance for a solo builder, potentially impacting feature velocity and stability.
- Monetization challenge in a market dominated by free and open-source alternatives; requires compelling value to convert users to a paid model.
- While the niche is growing, it is still relatively small compared to traditional CAD, limiting initial market size.
- User acquisition strategy needs to be highly targeted to reach the specific developer/engineer audience.
- Risk of users perceiving it as 'just another CAD-by-code tool' without understanding its unique value propositions.
Next steps
- Conduct in-depth user interviews with frustrated OpenSCAD/JSCAD/FreeCAD users to precisely pinpoint the features they would pay for.
- Experiment with different pricing models (e.g., freemium with advanced features, commercial licenses, one-time purchase for specific modules) to gauge willingness to pay.
- Focus MVP development on the 'narrowest wedge' – the absolute minimum features that solve a critical problem for a specific sub-segment and justify payment.
- Document a clear roadmap for features that address professional use cases where time savings translate directly to ROI.
Fly Labs Method
Is the pain real, is there a gap, is it the right time, can one person build it.
- Problem clarity
- 25
- Solution gap
- 22
- Willingness to pay
- 19
- Buildability
- 12
Strong problem and solution gap for scriptable CAD users, but build complexity and monetization in a free market pose challenges for a solo builder.
Value Equation
Dream outcome and how likely it feels, against the time and effort it costs.
Good market pain, strong value proposition, and niche growth, but high build complexity and monetization challenge in a free market.
One-Person Business
Curiosity pull, identity fit, and a path from free value to paid for a solo creator.
Strong problem clarity and creator fit, but the complexity of building/maintaining a CAD tool and monetization in a free market pose challenges for solo scaling.
Viral Frameworks
Hook strength, shareability, and how cheaply it can be tested.
Clear target audience and strong value proposition, but business model and long-term solo builder sustainability are key assumption risks.
Builder Lens
Evidence the problem exists, timing, defensibility, and a model that fits on a napkin.
Strong demand for a better code-CAD tool with a clear target, but validating the narrowest paid wedge and managing build complexity are key.
Why this verdict
Five lenses, one composite. How scoring works
The angle
This weekend
- Conduct in-depth user interviews with frustrated OpenSCAD/JSCAD/FreeCAD users to precisely pinpoint the features they would pay for.
- Experiment with different pricing models (e.g., freemium with advanced features, commercial licenses, one-time purchase for specific modules) to gauge willingness to pay.
- Focus MVP development on the 'narrowest wedge' – the absolute minimum features that solve a critical problem for a specific sub-segment and justify payment.
- Document a clear roadmap for features that address professional use cases where time savings translate directly to ROI.
Who is already there, emerging market
- OpenSCADVisit
A free software for creating solid 3D CAD objects using a descriptive programming language.
Pricing: Free and open-source.
- JSCADVisit
An open-source set of modular, browser, and command-line tools for creating parametric 2D and 3D designs with Javascript code.
Pricing: Free and open-source.
- CadQueryVisit
An intuitive, easy-to-use Python-based language for building parametric 3D CAD models, offering a Pythonic API and B-Rep modeling.
Pricing: Free and open-source.
- BlocksCADVisit
A free online platform designed to help students learn coding and CAD, and create using a block-based interface.
Pricing: $149/year starting price for individual users, with school licenses around $7.50 per student per year.
- FreeCADVisit
A free and open-source parametric 3D modeler primarily for designing real-life objects, with a traditional CAD approach and Python scripting capabilities.
Pricing: Free and open-source.
- AntimonyVisit
A computer-aided design (CAD) tool from a parallel universe in which CAD software evolved from Lisp machines rather than drafting tables.
Pricing: Free and open-source.
What they charge
Recent news
- Show HN: FluidCAD – Parametric CAD with JavaScript
Hacker News, April 10 2026
Market signals
The 'CAD by code' or scriptable CAD market appears to be a growing niche, driven by developers and engineers seeking reproducible, parametric, and automated design workflows. There's a strong emphasis on open-source solutions, with projects leveraging languages like Python and JavaScript. Recent discussions highlight the desire for better performance, improved user experience, and more advanced features within this paradigm.
What frustrates people
- OpenSCAD's mesh-based modeling is not ideal for smooth surfaces or CNC manufacturing, and its lack of an interactive UI can be cumbersome.
- FreeCAD is often perceived as difficult to learn and use, with a frustrating UI and instability issues.
- JSCAD lacks comprehensive features like advanced chamfers and fillets, and can be slower for complex operations.
- CadQuery's GUI development for macOS is lacking, and its dependency management (Anaconda, Docker) can be problematic.
- Users often express a desire for better performance, more intuitive model viewers, and advanced text editors in script-based CAD tools.
Semble – Code search for agents that uses 98% fewer tokens than grep
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Consus (YC F24) – LLM gateway for companies handling sensitive data
Hey Hacker News! I'm Eric, the founder of Consus. We route all AI requests to ITAR restricted and controlled unclassified information (CUI) compliant infrastructure. Consus itself satisfies ITAR restrictions, and we recently completed our FedRAMP equivalency audit against the 410 FedRAMP High controls. FedRAMP High is the U.S. government’s strictest security baseline for cloud services handling sensitive unclassified data. A breach of this data could cause severe or catastrophic harm. Achieving FedRAMP equivalency, or authorization, is required before processing CUI information.Demo: https://youtu.be/6MYxJe6P4oYAerospace and defense is experiencing rapid growth. Unfortunately, most companies are struggling to use AI because of necessary data protections & compliance risk. These companies can move even faster if they could use the AI tools that most other industries take for granted.I spent most of my career prior to Consus in aerospace & defense. I launched national security payloads at SpaceX, and was an early employee at Castelion. I’ve watched first hand how compliance red-tape makes it difficult for companies to adopt new technologies and trust vendors that touch their sensitive data. For example, I worked with a satellite manufacturer that doesn’t allow any AI tools, even for non-sensitive work.Even as AI has become extremely useful over the past 9-12 months, I was surprised by how many aerospace & defense companies refused to touch it. They could see how it could be helpful, but they were scared about model providers training on their data, violating an ITAR rule, or risk losing new business because of a failed cyber assessment. These are all rational fears.There were a lot of ways to solve some/all of these problems, but we focused on building a compliant AI inference layer that can "plug" into any AI tool or workflow. Just as OpenRouter integrates with most tools, Consus can connect to tools like ChatGPT or Clau
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