RepoSentry — AI Codebase Intelligence (Docs, Diagrams, Security, CI) built with Copilot CLI

# devchallenge# githubchallenge# githubcopilot# cli
RepoSentry — AI Codebase Intelligence (Docs, Diagrams, Security, CI) built with Copilot CLIMahesh

This is a submission for the GitHub Copilot CLI Challenge What I Built RepoSentry is an...

This is a submission for the GitHub Copilot CLI Challenge

What I Built

RepoSentry is an open-source CLI that answers the question every developer eventually hits:

“How do I understand this codebase fast enough to ship safely?”

Point it at any repository and it generates a full intelligence report:

  • Docs suite (README, API docs, setup, contributing, changelog, FAQ)
  • Architecture diagrams (Mermaid: dependency graph, data flow, ERD, API flow)
  • Security audit (pattern scan + Copilot analysis + threat model diagram)
  • CI/CD suggestions (GitHub Actions + Docker / Compose + production guide)
  • API testing assets (Postman collection + shell script + coverage report)
  • Performance anti-pattern scan + audit
  • Team templates (PR template, issue templates, CODEOWNERS, onboarding)
  • A weighted Health Score (A+ → F) with history + compare view

The goal is to make RepoSentry something you can clone and use immediately on any repo:

  • onboarding new teammates
  • evaluating OSS dependencies before adopting them
  • standardizing baseline docs/security/CI across multiple projects
  • creating a “before vs after” health score as you improve quality

RepoSentry is also intentionally demo-friendly (for judges): it has a preview server UI, progress spinners, and a clear final score summary.

Demo

Quick demo (3 minutes) 

# 1) install
npm i -g reposentry

# 2) run analysis in any repo
cd path/to/any-repo
reposentry analyze --force

# 3) open the UI
reposentry serve
# open http://localhost:3000
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“Judge mode” demo (shows uniqueness fast)

1) Run RepoSentry once

reposentry analyze --force
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2) Make a small improvement (add a README section, add CI, add tests)

3) Run again

reposentry analyze --force
reposentry compare
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4) Open the compare UI

reposentry serve
# click “Compare Scores”
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Screenshots

  • Full analysis run output
  • Copilot-powered fixes

(Images uploaded below.)

RepoSentry full analysis run

RepoSentry Copilot-powered fix (1)

RepoSentry Copilot-powered fix (2)

My Experience with GitHub Copilot CLI

This challenge asked us to build an application using GitHub Copilot CLI.

RepoSentry uses Copilot CLI in two ways:

1) Copilot CLI as the development partner

I used Copilot CLI during development to:

  • iterate on the CLI UX (commands, flags, interactive mode)
  • design a modular “engine” architecture (docs / security / CI / tests / etc.)
  • harden real security issues (output overwrite protection, server path traversal defenses, markdown sanitization)
  • write focused tests (Vitest) for the tricky parts

The biggest win: I could stay in the terminal, ask for a plan, refine prompts, and immediately turn those results into code with fast iteration.

2) Copilot CLI inside the product (the core superpower)

RepoSentry is not just “built with Copilot CLI” — it’s powered by it.

Under the hood, RepoSentry:

  • scans your repository (languages/frameworks, routes/models/imports, git history)
  • builds a structured prompt context (file tree + detected signals)
  • calls Copilot CLI to generate outputs for each engine
  • writes results into a consistent .reposentry/ folder

Example outputs you can open immediately:

  • HEALTH_REPORT.md + analysis.json
  • ARCHITECTURE.md + diagrams/*.mmd
  • security/SECURITY_AUDIT.md + security/threat-model.mmd
  • infrastructure/ci.yml and deployment guidance

Reliability + safety choices (important for real repos)

  • RepoSentry never asks Copilot to write into your repo directly.
  • It writes generated files only into the configured output directory.
  • The preview server blocks path traversal and escapes raw HTML in markdown.
  • If Copilot CLI isn’t installed/logged-in, RepoSentry still runs and produces placeholder outputs.

How to Run It (for judges) 

npm i -g reposentry

# in any project
reposentry analyze --force
reposentry serve
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If Copilot CLI isn’t configured yet:

  • Install Copilot CLI: npm i -g @github/copilot (or winget install GitHub.Copilot on Windows)
  • Authenticate: run copilot once and use /login

Links