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Dário Pimentel
Dário Pimentel

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RepoLens AI — Understand Any GitHub Repository in Seconds

GitHub Copilot CLI Challenge Submission

This is a submission for the GitHub Copilot CLI Challenge

What I Built

RepoLens AI is an AI-powered web application that instantly analyzes any public GitHub repository and delivers a comprehensive technical report — complete with stunning, zero-dependency SVG visualizations you won't find anywhere else.

Paste a GitHub URL, and in seconds you get:

  • Architectural Summary
  • Full Stack Breakdown
  • Strengths & ⚠️ Weaknesses
  • Improvement Suggestions
  • Beginner-Friendly Tasks

But what truly sets RepoLens AI apart are its 5 unique visualizations, all built in pure SVG with zero chart libraries:

Visualization What it does
Language Ring Animated donut chart with official GitHub language colors
Health Radar Pentagon radar chart scoring 5 health dimensions
Architecture Graph Interactive node graph of the project's folder structure with collapse/expand breathe animation
Repo Personality Myers-Briggs style analysis — assigns an archetype (Pioneer, Guardian, Architect, Sprinter, Scholar, Community) with traits, radar chart, and dimension breakdown
Hero Orb Atmospheric animated background orb for visual depth

The app also features:

  • Full i18n — English (default) + Portuguese, with AI responses respecting the selected language
  • Responsive design — Desktop 2-column grid for Strengths/Weaknesses, mobile-first everywhere
  • Copy & Export — Copy analysis to clipboard or download as .md
  • Analysis timer — Shows how long the AI took
  • History — Recently analyzed repos saved locally
  • Smart fallback — Graceful degradation when AI quota is exceeded

Tech Stack: React 19 + Vite 7.3 + TailwindCSS v4 | Express 5 + ES Modules | Google Gemini AI with automatic model discovery and fallback chain | GitHub REST API

Demo

🔗 Live App: repolens-ai.vercel.app

Repository: https://github.com/DARIO-engineer/RepoLens.AI

Screenshots

The clean landing page with animated orb background

AI-generated analysis with responsive 2-column layout on desktop

Language DNA donut ring and Health Radar pentagon — pure SVG, zero libraries

Interactive Architecture Graph with radial layout — click the center node to trigger the collapse/expand breathe animation

Repo Personality — Myers-Briggs for repositories. Archetype, traits, radar chart, and dimension breakdown

Built with Copilot CLI showcase — real commands used during development

Full i18n: one click to switch between English and Portuguese

My Experience with GitHub Copilot CLI

GitHub Copilot CLI wasn't just a helper in this project — it was my pair programming partner from start to finish. Every major feature, every tricky bug, every architectural decision went through gh copilot in the terminal.

How I Used It

1. Architecture & Refactoring

$ gh copilot suggest "refactor express server into modular architecture with services and routes"
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Copilot suggested creating services/github.js, services/gemini.js, and routes/analyze.js with clean separation of concerns. What would have taken me 30+ minutes of planning happened in seconds.

2. Critical Bug Resolution

$ gh copilot explain "why is API_KEY undefined when using ES modules with dotenv"
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This was a showstopper. ES module imports are hoisted, so dotenv.config() runs after the imports that need the env vars. Copilot immediately identified the issue and suggested import "dotenv/config" as the first import. Bug fixed in under 10 seconds.

3. Zero-Dependency Visualizations

$ gh copilot suggest "create an SVG pentagon radar chart in React without any chart library"
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The Health Radar visualization was born from this single command. Copilot generated polar coordinate calculations, requestAnimationFrame animation, and interactive hover — all in pure SVG. I then refined it, but the foundation was solid from the start.

4. AI Output Normalization

$ gh copilot suggest "build a normalizeAnalysis function that transforms any AI output format into canonical sections"
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Gemini's output format is unpredictable. Copilot generated a fuzzy-matching system with accent stripping, universal header regex, and variation mapping that makes the analysis 100% consistent regardless of how Gemini formats its response.

5. Performance Optimization

$ gh copilot suggest "smart file tree filtering for GitHub repos to reduce prompt size"
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Created an intelligent filter system with CODE_EXTENSIONS, IMPORTANT_FILES, and IGNORED_PATTERNS to keep the file tree compact. This reduced prompt size by ~60%, making analysis faster and cheaper.

6. Frontend Polish

$ gh copilot suggest "animated SVG donut chart for language breakdown with GitHub official colors"
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The Language Ring visualization came from this — cubic ease-out animation, hover glow effects, 35+ official GitHub language colors with HSL fallback.

Impact by the Numbers

Metric Value
CLI commands used 40+
Bugs resolved 12
Features generated 8
Estimated time saved ~6 hours

What I Learned

Copilot CLI fundamentally changed how I approach development:

  • Think in prompts, not code — Instead of writing boilerplate, I describe what I want and refine the output
  • Debug fastergh copilot explain is incredibly powerful for understanding why something fails, not just what failed
  • Architectural confidence — Using gh copilot suggest for structure decisions gives you well-reasoned patterns immediately
  • Zero-dependency mindset — Copilot helped me build complex SVG visualizations that would normally require Chart.js or D3 — keeping the bundle lean (96KB gzipped JS)

The CLI workflow is addictive. No context switching to a browser, no copy-pasting from StackOverflow. Just terminal → prompt → solution → build. This is how I want to develop from now on.


Built with ❤️ by DARIO-engineer using GitHub Copilot CLI v0.0.410

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