Tech Stack Detector Skill

This skill provides intelligent detection of technologies, frameworks, and tools used in a project.

Detection Matrix

Languages

Language	Detection Files	Indicators
TypeScript	tsconfig.json, *.ts, *.tsx	"typescript" in deps
JavaScript	*.js, *.jsx, jsconfig.json	No tsconfig
Python	pyproject.toml, setup.py, *.py	python, pip, poetry
Go	go.mod, go.sum, *.go	module declaration
Rust	Cargo.toml, *.rs	[package] section
Java	pom.xml, build.gradle, *.java	Maven/Gradle markers
C#	*.csproj, *.sln	MSBuild configs
Ruby	Gemfile, *.rb	gem declarations
PHP	composer.json, *.php	"require" section

Frontend Frameworks

Framework	Detection	Key Indicators
React	react in deps	JSX files, hooks patterns
Vue	vue in deps	.vue files, Options/Composition API
Angular	@angular/core	*.component.ts, decorators
Svelte	svelte in deps	.svelte files
Next.js	next in deps	pages/ or app/ directory
Nuxt	nuxt in deps	nuxt.config.*
Remix	@remix-run/*	app/routes/ structure
Astro	astro in deps	.astro files

Backend Frameworks

Framework	Detection	Key Indicators
Express	express in deps	app.use(), route handlers
Fastify	fastify in deps	Plugin architecture
NestJS	@nestjs/core	Decorators, modules
Django	django in requirements	settings.py, urls.py
FastAPI	fastapi in requirements	@app.get() decorators
Flask	flask in requirements	@app.route()
Spring	spring-boot in pom	@RestController
Rails	rails in Gemfile	MVC structure
Laravel	laravel/framework	artisan, routes/web.php

Desktop Frameworks

Framework	Detection	Key Indicators
Electron	electron in deps	main.js, preload.js
Tauri	@tauri-apps/*	tauri.conf.json
Qt	CMakeLists.txt + Qt	#include <Qt*>

Build Tools

Tool	Detection File	Config Pattern
Vite	vite.config.*	defineConfig()
Webpack	webpack.config.*	module.exports = {}
Rollup	rollup.config.*	export default {}
esbuild	esbuild.config.*	build() calls
Turbo	turbo.json	pipeline config
Nx	nx.json	projects, generators
Parcel	package.json "source"	No config file needed
SWC	.swcrc	jsc config

Package Managers

Manager	Detection File	Lock File
npm	package.json	package-lock.json
yarn	package.json	yarn.lock
pnpm	package.json	pnpm-lock.yaml
bun	package.json	bun.lockb
pip	requirements.txt	-
poetry	pyproject.toml	poetry.lock
cargo	Cargo.toml	Cargo.lock
maven	pom.xml	-
gradle	build.gradle	gradle.lockfile

Testing Frameworks

Framework	Detection	Config File
Jest	jest in deps	jest.config.*
Vitest	vitest in deps	vitest.config.*
Mocha	mocha in deps	.mocharc.*
Cypress	cypress in deps	cypress.config.*
Playwright	@playwright/test	playwright.config.*
Pytest	pytest in requirements	pytest.ini, pyproject.toml
JUnit	pom.xml + junit	-
RSpec	rspec in Gemfile	.rspec

Databases

Database	Detection	Connection Patterns
PostgreSQL	pg, psycopg2	postgres://, postgresql://
MySQL	mysql2, mysqlclient	mysql://
MongoDB	mongodb, mongoose	mongodb://
Redis	redis, ioredis	redis://
SQLite	sqlite3, better-sqlite3	.db, .sqlite files
Prisma	@prisma/client	schema.prisma
Drizzle	drizzle-orm	drizzle.config.ts

Cloud & Infrastructure

Service	Detection	Config
AWS	@aws-sdk/*	.aws/, serverless.yml
GCP	@google-cloud/*	gcloud references
Azure	@azure/*	azure-pipelines.yml
Vercel	vercel in deps	vercel.json
Docker	Dockerfile	docker-compose.yml
Kubernetes	k8s manifests	*.yaml with apiVersion
Terraform	*.tf files	main.tf, variables.tf

Detection Algorithm

async function detectTechStack(projectRoot: string): Promise<TechStack> {
  const detections: Detection[] = [];

  // Phase 1: File-based detection (fast)
  const files = await glob(['package.json', 'tsconfig.json', '*.config.*', ...]);
  for (const file of files) {
    detections.push(...detectFromFile(file));
  }

  // Phase 2: Content-based detection (selective)
  const sampleFiles = selectRepresentativeFiles(projectRoot);
  for (const file of sampleFiles) {
    detections.push(...detectFromContent(file));
  }

  // Phase 3: Confidence scoring
  const stack = aggregateDetections(detections);
  return rankByConfidence(stack);
}

Output Format

## Tech Stack Analysis

### Primary Technologies
| Technology | Version | Confidence | Evidence |
|------------|---------|------------|----------|
| TypeScript | 5.3.x | HIGH | tsconfig.json, *.ts files |
| React | 18.x | HIGH | package.json, JSX patterns |
| Next.js | 14.x | HIGH | next.config.js, app/ directory |

### Build & Development
| Tool | Version | Purpose |
|------|---------|---------|
| pnpm | 8.x | Package manager |
| Turbo | 1.x | Monorepo build |
| Vite | 5.x | Dev server, bundling |

### Testing
| Framework | Coverage | Purpose |
|-----------|----------|---------|
| Jest | HIGH | Unit tests |
| Playwright | MEDIUM | E2E tests |

### Infrastructure
| Service | Purpose |
|---------|---------|
| Docker | Containerization |
| Vercel | Deployment |

### Uncertain Detections
⚠️ Redis: Found redis dependency but no connection config
⚠️ GraphQL: Found @apollo/client but no schema files

Integration with Steering

When invoked during /steering:

1. Phase 2 (Tech Discovery) automatically uses this skill
2. Populates tech.md with detected stack
3. Generates accurate build commands
4. Identifies environment variable requirements
5. Detects testing framework for test commands

Confidence Levels

HIGH:   Config file + code evidence + dependencies
MEDIUM: Config file + dependencies (no code evidence)
LOW:    Dependencies only (may be unused)