Library Detection Skill Skill

Library Detection Skill

Automatically detect the technology stack of a project by analyzing package manifests and configuration files. Returns structured data for use in onboarding, documentation discovery, and tool configuration.

Variables

| Variable | Default | Description | |----------|---------|-------------| | SCAN_DEPTH | 3 | Max directory depth to search for manifests | | INCLUDE_DEV_DEPS | true | Include development dependencies in analysis | | DETECT_FRAMEWORKS | true | Identify frameworks from dependencies | | DETECT_TEST_TOOLS | true | Identify test frameworks and runners | | OUTPUT_FORMAT | json | Output format: json, markdown, or toon |

Instructions

MANDATORY - Follow the Workflow steps below in order. Do not skip steps.

Scan for package manifests in the project
Parse each manifest to extract dependencies
Classify dependencies into categories
Detect frameworks and test tools from dependency patterns
Output structured stack summary

Red Flags - STOP and Reconsider

If you're about to:

Assume a framework without checking imports or config files
Skip manifest files because "the project is simple"
Hardcode framework versions instead of reading from manifests
Report a library without verifying it's actually used

STOP -> Read the manifest files -> Verify with imports/configs -> Then report

Workflow

1. Discover Manifests

Scan for these files (in order of priority):

| File | Language | Parser | |------|----------|--------| | package.json | JavaScript/TypeScript | JSON | | pyproject.toml | Python | TOML | | requirements.txt | Python | Line-based | | go.mod | Go | Go mod | | Cargo.toml | Rust | TOML | | pubspec.yaml | Dart/Flutter | YAML | | CMakeLists.txt | C/C++ | CMake | | meson.build | C/C++ | Meson | | WORKSPACE | Bazel | Bazel | | pom.xml | Java | XML | | build.gradle | Java/Kotlin | Gradle DSL | | Gemfile | Ruby | Ruby DSL | | composer.json | PHP | JSON |

Also check for:

Dockerfile - containerization
docker-compose.yml - container orchestration
.github/workflows/*.yml - CI/CD
Makefile - build system
tsconfig.json - TypeScript config
vite.config.* / webpack.config.* - bundlers

2. Parse Dependencies

For each manifest, extract:

Production dependencies: runtime requirements
Development dependencies: build/test tools
Peer dependencies: expected host environment
Optional dependencies: feature flags

3. Classify Stack

Group findings into:

{
  "languages": ["typescript", "python", "go", "rust", "dart", "cpp"],
  "frameworks": [
    {"name": "react", "version": "^18.0.0", "category": "frontend"},
    {"name": "fastapi", "version": "^0.100.0", "category": "backend"}
  ],
  "test_frameworks": [
    {"name": "vitest", "version": "^1.0.0"},
    {"name": "pytest", "version": "^7.0.0"}
  ],
  "build_tools": ["vite", "uv", "docker"],
  "databases": ["postgresql", "redis"],
  "cloud_providers": ["aws", "vercel"],
  "ci_cd": ["github-actions"]
}

4. Framework Detection Patterns

Use the cookbook for specific detection logic:

Read ./cookbook/manifest-parsing.md for parsing rules
Match dependency names against known framework patterns

5. Output

Return the structured stack summary in the requested format.

Cookbook

Manifest Parsing

IF: Parsing any package manifest
THEN: Read and execute ./cookbook/manifest-parsing.md

Quick Reference

Detection Patterns

| Dependency Pattern | Detected As | |--------------------|-------------| | react, react-dom | React framework | | vue, @vue/* | Vue framework | | next | Next.js framework | | fastapi | FastAPI framework | | django | Django framework | | flask | Flask framework | | express | Express.js framework | | vitest, jest | JavaScript test framework | | pytest | Python test framework | | gtest, gmock, catch2 | C/C++ test framework | | flutter, flutter_test | Flutter framework | | @testing-library/* | Testing utilities |

Category Mappings

| Category | Examples | |----------|----------| | frontend | react, vue, svelte, angular | | backend | fastapi, django, express, gin | | database | prisma, sqlalchemy, typeorm | | testing | vitest, jest, pytest, playwright | | build | vite, webpack, esbuild, rollup | | linting | eslint, prettier, ruff, black | | typing | typescript, mypy, pyright | | build-native | cmake, meson, bazel |

Output Schema

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "project_root": {"type": "string"},
    "scanned_at": {"type": "string", "format": "date-time"},
    "languages": {
      "type": "array",
      "items": {"type": "string"}
    },
    "frameworks": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "name": {"type": "string"},
          "version": {"type": "string"},
          "category": {"type": "string"}
        }
      }
    },
    "test_frameworks": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "name": {"type": "string"},
          "version": {"type": "string"}
        }
      }
    },
    "build_tools": {
      "type": "array",
      "items": {"type": "string"}
    },
    "databases": {
      "type": "array",
      "items": {"type": "string"}
    },
    "cloud_providers": {
      "type": "array",
      "items": {"type": "string"}
    },
    "ci_cd": {
      "type": "array",
      "items": {"type": "string"}
    },
    "manifests_found": {
      "type": "array",
      "items": {"type": "string"}
    }
  }
}

Integration

Other skills and commands can use this skill for:

Documentation discovery: Map detected frameworks to doc sources
Onboarding: Generate quickstart guides tailored to the stack
Tool configuration: Auto-configure linters, formatters, test runners
Agent routing: Select appropriate AI providers based on stack

Example usage in another skill:

## Prerequisites

Before implementing, run the `library-detection` skill to identify:
- Test frameworks (for writing tests)
- Build tools (for verification)
- Database libraries (for data layer work)

Agent Skills: Library Detection Skill

Install this agent skill to your local

Skill Files