unbuilt.app AGENTS.md

AGENTS.md — unbuilt.app

Tech stack detection for websites via Playwright + pattern matching.

Project Structure

Monorepo (yarn workspaces + turborepo):

apps/cli/          — CLI tool (`unbuilt <url>`)
apps/web/          — Next.js web app (unbuilt.app)
packages/analyzer/ — Orchestrates detection: navigates page, runs all detectors, two-pass analysis
packages/features/ — Detection categories & patterns (this is where you add new detections)
packages/helpers/  — Shared utilities
packages/resources/— Resource tracking (scripts, stylesheets, etc.)

How Detection Works

1. Resources are collected from a live page (scripts, stylesheets, documents, headers, filenames)
2. Patterns match against those resources using regex and browser checks
3. Two-pass analysis: first pass detects everything independently, second pass runs dependencies checks so categories can reference each other's results
4. Each category returns: { name, confidence, detectedFeatures, secondaryMatches }

Pattern Interface

interface Pattern {
  score: number;           // Weight (0-1). Higher = stronger signal
  name: string;            // Identifier for this pattern
  scripts?: RegExp[];      // Match against JS bundle contents
  stylesheets?: RegExp[];  // Match against CSS contents
  documents?: RegExp[];    // Match against HTML document
  headers?: Record<string, RegExp>; // Match against HTTP headers
  filenames?: RegExp[];    // Match against resource URLs
  browser?: (page, browser) => boolean | Promise<boolean>; // Runtime check
  dependencies?: (analysis) => boolean; // Cross-category dependency check (2nd pass)
}

Key Types

• Pattern — packages/features/src/types/pattern.ts
• FeatureResult — packages/features/src/types/feature.ts
• CalculationResult — packages/features/src/types/feature.ts
• AnalysisFeatures — packages/features/src/types/analysis.ts
• AnalyzeResult — packages/analyzer/src/types.ts

Adding a Pattern to an Existing Category