Stack Detection

This skill provides comprehensive technology stack detection for any project. It goes beyond simple file-existence checks to analyze actual configurations, versions, and usage patterns.

When to Use

• At the start of any blueprint-dev workflow (/blueprint-dev:bp:discover)
• When agents need to adapt their output to the project's specific stack
• When generating CLAUDE.md suggestions based on detected technologies

How It Works

Detection Layers

1. Manifest Analysis: Read package managers (package.json, composer.json, Gemfile, etc.) for declared dependencies
2. Config File Analysis: Read framework configs for specific settings (e.g., Next.js app router vs pages router)
3. Code Pattern Analysis: Grep source files for usage patterns that confirm or refine detections
4. Infrastructure Analysis: Check for Docker, CI/CD, deployment configs

Fingerprint Matching

Use the fingerprints in references/fingerprints.md to match specific technologies. Each fingerprint has:

• Primary signal: File or pattern that strongly indicates the technology
• Confirming signals: Additional evidence that increases confidence
• Version detection: How to determine the specific version in use
• Variant detection: Sub-variants (e.g., Next.js App Router vs Pages Router)

Output

Results go to .blueprint/stack-profile.json using the template in references/profile-template.md.

Key Principles

• Verify, don't guess: Only report technologies you can confirm through multiple signals
• Version matters: react@18 and react@19 may need different agent behavior
• Conventions matter more than dependencies: How the project uses a technology is more valuable than knowing it's installed
• Fast by default: The SessionStart hook does a quick scan; deep analysis happens only when /discover is explicitly run