Describe your app. Get a buildable system design.
Free Claude skill that designs your application using the 7 building blocks framework.
You give it one paragraph about what your app does. It walks you through 5 questions about users, external services, scheduled work, and your features. It hands back a labeled architecture: which blocks you need, why, and a recommended technology for each. Works on claude.ai. Works in Claude Code. Apache 2.0.
Free · Open source · No signup
This is what you get.
A real example. Generated from the paragraph below.
The input
"Photo Backup. A private app that auto-uploads photos from your phone and generates thumbnails for fast browsing. Users sign in, photos sync in the background to a personal library, and a thumbnail grid loads instantly even on a slow connection. No social features, no comments, no algorithm. Just the photos."
Output 1 of 2 — the architecture diagram
Output 2 of 2 — the markdown design doc
The diagram and the doc are both the output. The diagram shows you the shape; the doc tells your coding tool exactly what to build.
How it works
Describe the app
One or two sentences. What does it do? Who uses it?
Answer 2 quick questions
Users (humans, AI agents, both?) and external forces (third-party APIs, scheduled work).
Walk through 3-5 features
Plain English. The skill decomposes each feature into the blocks it needs.
Get the design
A markdown design doc, an architecture diagram PNG, and per-block technology recommendations.
Total time: about 10 minutes of conversation.
Install in 30 seconds
Pick the surface you already use.
On claude.ai
Settings → Capabilities → Skills → Add Skill. Upload the zipped repo, or paste the GitHub URL.
Download .zipIn Claude Code
Clone the repo into your skills directory and you are done.
git clone https://github.com/systemthinkinglab/design-with-blocks-plugin \
~/.claude/skills/design-with-blocksThen invoke with /design-with-blocks in any session.
What this skill does not do
Honest framing so you know exactly what you are getting.
It does not write your app code.
Pattern-first design ends at the architecture. The skill hands the doc to your coding tool; the coding tool builds it.
It does not teach you to design any future system on your own.
It generates one plan. The thinking that lets you generate plans without it lives in Course I.
This skill gets you started with one design.
Course I teaches the thinking behind it, so the next design is yours.
The codebase you just inherited becomes legible. The system design interview becomes a structured conversation. The AI-generated architecture lands on your desk and you can tell whether it is right. That fluency is what Course I builds, through hands-on discovery labs, AI-graded design challenges, and case studies of Instagram, Netflix, and Uber.
Launch price · becomes $149