---
name: skill-master
description: Discover codebase patterns and auto-generate SKILL files for .claude/skills/. Use when analyzing project for missing skills, creating new skills from codebase patterns, or syncing skills with project structure.
version: 1.0.0
---

# Skill Master

## Overview

Analyze codebase to discover patterns and generate/update SKILL files in `.claude/skills/`. Supports multi-platform projects with stack-specific pattern detection.

**Capabilities:**
- Scan codebase for architectural patterns (ViewModel, Repository, Room, etc.)
- Compare detected patterns with existing skills
- Auto-generate SKILL files with real code examples
- Version tracking and smart updates

## How the AI discovers and uses this skill

This skill triggers when user:
- Asks to analyze project for missing skills
- Requests skill generation from codebase patterns
- Wants to sync or update existing skills
- Mentions "skill discovery", "generate skills", or "skill-sync"

**Detection signals:**
- `.claude/skills/` directory presence
- Project structure matching known patterns
- Build/config files indicating platform (see references)

## Modes

### Discover Mode

Analyze codebase and report missing skills.

**Steps:**
1. Detect platform via build/config files (see references)
2. Scan source roots for pattern indicators
3. Compare detected patterns with existing `.claude/skills/`
4. Output gap analysis report

**Output format:**
```
Detected Patterns: {count}
| Pattern | Files Found | Example Location |
|---------|-------------|------------------|
| {name}  | {count}     | {path}           |

Existing Skills: {count}
Missing Skills: {count}
- {skill-name}: {pattern}, {file-count} files found
```

### Generate Mode

Create SKILL files from detected patterns.

**Steps:**
1. Run discovery to identify missing skills
2. For each missing skill:
   - Find 2-3 representative source files
   - Extract: imports, annotations, class structure, conventions
   - Extract rules from `.ruler/*.md` if present
3. Generate SKILL.md using template structure
4. Add version and source marker

**Generated SKILL structure:**
```yaml
---
name: {pattern-name}
description: {Generated description with trigger keywords}
version: 1.0.0
---

# {Title}

## Overview
{Brief description from pattern analysis}

## File Structure
{Extracted from codebase}

## Implementation Pattern
{Real code examples - anonymized}

## Rules
### Do
{From .ruler/*.md + codebase conventions}

### Don't
{Anti-patterns found}

## File Location
{Actual paths from codebase}
```

## Create Strategy

When target SKILL file does not exist:
1. Generate new file using template
2. Set `version: 1.0.0` in frontmatter
3. Include all mandatory sections
4. Add source marker at end (see Marker Format)

## Update Strategy

**Marker check:** Look for `<!-- Generated by skill-master command` at file end.

**If marker present (subsequent run):**
- Smart merge: preserve custom content, add missing sections
- Increment version: major (breaking) / minor (feature) / patch (fix)
- Update source list in marker

**If marker absent (first run on existing file):**
- Backup: `SKILL.md` → `SKILL.md.bak`
- Use backup as source, extract relevant content
- Generate fresh file with marker
- Set `version: 1.0.0`

## Marker Format

Place at END of generated SKILL.md:

```html
<!-- Generated by skill-master command
Version: {version}
Sources:
- path/to/source1.kt
- path/to/source2.md
- .ruler/rule-file.md
Last updated: {YYYY-MM-DD}
-->
```

## Platform References

Read relevant reference when platform detected:

| Platform | Detection Files | Reference |
|----------|-----------------|-----------|
| Android/Gradle | `build.gradle`, `settings.gradle` | `references/android.md` |
| iOS/Xcode | `*.xcodeproj`, `Package.swift` | `references/ios.md` |
| React (web) | `package.json` + react | `references/react-web.md` |
| React Native | `package.json` + react-native | `references/react-native.md` |
| Flutter/Dart | `pubspec.yaml` | `references/flutter.md` |
| Node.js | `package.json` | `references/node.md` |
| Python | `pyproject.toml`, `requirements.txt` | `references/python.md` |
| Java/JVM | `pom.xml`, `build.gradle` | `references/java.md` |
| .NET/C# | `*.csproj`, `*.sln` | `references/dotnet.md` |
| Go | `go.mod` | `references/go.md` |
| Rust | `Cargo.toml` | `references/rust.md` |
| PHP | `composer.json` | `references/php.md` |
| Ruby | `Gemfile` | `references/ruby.md` |
| Elixir | `mix.exs` | `references/elixir.md` |
| C/C++ | `CMakeLists.txt`, `Makefile` | `references/cpp.md` |
| Unknown | - | `references/generic.md` |

If multiple platforms detected, read multiple references.

## Rules

### Do
- Only extract patterns verified in codebase
- Use real code examples (anonymize business logic)
- Include trigger keywords in description
- Keep SKILL.md under 500 lines
- Reference external files for detailed content
- Preserve custom sections during updates
- Always backup before first modification

### Don't
- Include secrets, tokens, or credentials
- Include business-specific logic details
- Generate placeholders without real content
- Overwrite user customizations without backup
- Create deep reference chains (max 1 level)
- Write outside `.claude/skills/`

## Content Extraction Rules

**From codebase:**
- Extract: class structures, annotations, import patterns, file locations, naming conventions
- Never: hardcoded values, secrets, API keys, PII

**From .ruler/*.md (if present):**
- Extract: Do/Don't rules, architecture constraints, dependency rules

## Output Report

After generation, print:
```
SKILL GENERATION REPORT

Skills Generated: {count}

{skill-name} [CREATED | UPDATED | BACKED_UP+CREATED]
├── Analyzed: {file-count} source files
├── Sources: {list of source files}
├── Rules from: {.ruler files if any}
└── Output: .claude/skills/{skill-name}/SKILL.md ({line-count} lines)

Validation:
✓ YAML frontmatter valid
✓ Description includes trigger keywords
✓ Content under 500 lines
✓ Has required sections
```

## Safety Constraints

- Never write outside `.claude/skills/`
- Never delete content without backup
- Always backup before first-time modification
- Preserve user customizations
- Deterministic: same input → same output