tianzecn Deep Code Analysis
This Skill provides comprehensive codebase investigation capabilities using the codebase-detective agent with semantic search and pattern matching.
Prerequisites (MANDATORY)
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║ BEFORE INVOKING THIS SKILL ║
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║ ║
║ 1. INVOKE code-search-selector skill FIRST ║
║ → Validates tool selection (claudemem vs grep) ║
║ → Checks if claudemem is indexed ║
║ → Prevents tool familiarity bias ║
║ ║
║ 2. VERIFY claudemem status ║
║ → Run: claudemem status ║
║ → If not indexed: claudemem index -y ║
║ ║
║ 3. DO NOT start with Read/Glob ║
║ → Even if file paths are mentioned in the prompt ║
║ → Semantic search first, Read specific lines after ║
║ ║
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When to use this Skill
Claude should invoke this Skill when:
- User asks "how does [feature] work?"
- User wants to understand code architecture or patterns
- User is debugging and needs to trace code flow
- User asks "where is [functionality] implemented?"
- User needs to find all usages of a component/service
- User wants to understand dependencies between files
- User mentions: "investigate", "analyze", "find", "trace", "understand"
- User is exploring an unfamiliar codebase
- User needs to understand complex multi-file functionality
Instructions
Phase 1: Determine Investigation Scope
Understand what the user wants to investigate:
- Specific Feature: "How does user authentication work?"
- Find Implementation: "Where is the payment processing logic?"
- Trace Flow: "What happens when I click the submit button?"
- Debug Issue: "Why is the profile page showing undefined?"
- Find Patterns: "Where are all the API calls made?"
- Analyze Architecture: "What's the structure of the data layer?"
Phase 2: Invoke codebase-detective Agent
Use the Task tool to launch the codebase-detective agent with comprehensive instructions:
Use Task tool with:
- subagent_type: "code-analysis:detective"
- description: "Investigate [brief summary]"
- prompt: [Detailed investigation instructions]
Prompt structure for codebase-detective:
# Code Investigation Task
## Investigation Target
[What needs to be investigated - be specific]
## Context
- Working Directory: [current working directory]
- Purpose: [debugging/learning/refactoring/etc]
- User's Question: [original user question]
## Investigation Steps
1. **Initial Search** (CLAUDEMEM REQUIRED):
- FIRST: Check `claudemem status` - is index available?
- ALWAYS: Use `claudemem search "semantic query"` for investigation
- NEVER: Use grep/glob for semantic understanding tasks
- Search for: [concepts, functionality, patterns by meaning]
2. **Code Location**:
- Find exact file paths and line numbers
- Identify entry points and main implementations
- Note related files and dependencies
3. **Code Flow Analysis**:
- Trace how data/control flows through the code
- Identify key functions and their roles
- Map out component/service relationships
4. **Pattern Recognition**:
- Identify architectural patterns used
- Note code conventions and styles
- Find similar implementations for reference
## Deliverables
Provide a comprehensive report including:
1. **📍 Primary Locations**:
- Main implementation files with line numbers
- Entry points and key functions
- Configuration and setup files
2. **🔍 Code Flow**:
- Step-by-step flow explanation
- How components interact
- Data transformation points
3. **🗺️ Architecture Map**:
- High-level structure diagram
- Component relationships
- Dependency graph
4. **📝 Code Snippets**:
- Key implementations (show important code)
- Patterns and conventions used
- Notable details or gotchas
5. **🚀 Navigation Guide**:
- How to explore the code further
- Related files to examine
- Commands to run for testing
6. **💡 Insights**:
- Why the code is structured this way
- Potential issues or improvements
- Best practices observed
## Search Strategy
### ⚠️ CRITICAL: Tool Selection
**BEFORE ANY SEARCH, CHECK CLAUDEMEM STATUS:**
```bash
claudemem status
✅ PRIMARY METHOD: claudemem (Indexed Memory)
# Index if needed
claudemem index -y
# Semantic search (ALWAYS use this for investigation)
claudemem search "authentication login session" -n 15
claudemem search "API endpoint handler route" -n 20
claudemem search "data transformation pipeline" -n 10
Why claudemem is REQUIRED for investigation:
- Understands code MEANING, not just text patterns
- Finds related code even with different terminology
- Returns ranked, relevant results
- AST-aware (understands code structure)
❌ WHEN NOT TO USE GREP
| User Request | ❌ DON'T | ✅ DO |
|---|---|---|
| "How does auth work?" | grep -r "auth" src/ |
claudemem search "authentication flow" |
| "Find API endpoints" | grep -r "router" src/ |
claudemem search "API endpoint handler" |
| "Trace data flow" | grep -r "transform" src/ |
claudemem search "data transformation" |
| "Audit architecture" | ls -la src/ |
claudemem search "architecture layers" |
⚠️ DEGRADED FALLBACK (Only if claudemem unavailable)
Only use grep/find if:
- claudemem is NOT installed, AND
- User explicitly accepts degraded mode
# DEGRADED MODE - inferior results expected
grep -r "pattern" src/ # Text match only, no semantic understanding
find . -name "*.ts" # File discovery only
Always warn user: "Using grep fallback - results will be less accurate than semantic search."
Output Format
Structure your findings clearly with:
- File paths using backticks:
src/auth/login.ts:45 - Code blocks for snippets
- Clear headings and sections
- Actionable next steps
### Phase 3: Present Analysis Results
After the agent completes, present results to the user:
1. **Executive Summary** (2-3 sentences):
- What was found
- Where it's located
- Key insight
2. **Detailed Findings**:
- Primary file locations with line numbers
- Code flow explanation
- Architecture overview
3. **Visual Structure** (if complex):
EntryPoint (file:line) ├── Validator (file:line) ├── BusinessLogic (file:line) │ └── DataAccess (file:line) └── ResponseHandler (file:line)
4. **Code Examples**:
- Show key code snippets inline
- Highlight important patterns
5. **Next Steps**:
- Suggest follow-up investigations
- Offer to dive deeper into specific parts
- Provide commands to test/run the code
### Phase 4: Offer Follow-up
Ask the user:
- "Would you like me to investigate any specific part in more detail?"
- "Do you want to see how [related feature] works?"
- "Should I trace [specific function] further?"
## Example Scenarios
### Example 1: Understanding Authentication
User: "How does login work in this app?"
Skill invokes codebase-detective agent with: "Investigate user authentication and login flow:
- Find login API endpoint or form handler
- Trace authentication logic
- Identify token generation/storage
- Find session management
- Locate authentication middleware"
Agent provides:
- src/api/auth/login.ts:34-78 (login endpoint)
- src/services/authService.ts:12-45 (JWT generation)
- src/middleware/authMiddleware.ts:23 (token validation)
- Flow: Form → API → Service → Middleware → Protected Routes
### Example 2: Debugging Undefined Error
User: "The dashboard shows 'undefined' for user name"
Skill invokes codebase-detective agent with: "Debug undefined user name in dashboard:
- Find Dashboard component
- Locate where user name is rendered
- Trace user data fetching
- Check data transformation/mapping
- Identify where undefined is introduced"
Agent provides:
- src/components/Dashboard.tsx:156 renders user.name
- src/hooks/useUser.ts:45 fetches user data
- Issue: API returns 'full_name' but code expects 'name'
- Fix: Map 'full_name' to 'name' in useUser hook
### Example 3: Finding All API Calls
User: "Where are all the API calls made?"
Skill invokes codebase-detective agent with: "Find all API call locations:
- Search for fetch, axios, http client usage
- Identify API client/service files
- List all endpoints used
- Note patterns (REST, GraphQL, etc)
- Find error handling approach"
Agent provides:
- 23 API calls across 8 files
- Centralized in src/services/*
- Using axios with interceptors
- Base URL in src/config/api.ts
- Error handling in src/utils/errorHandler.ts
## Success Criteria
The Skill is successful when:
1. ✅ User's question is comprehensively answered
2. ✅ Exact code locations provided with line numbers
3. ✅ Code relationships and flow clearly explained
4. ✅ User can navigate to code and understand it
5. ✅ Architecture patterns identified and explained
6. ✅ Follow-up questions anticipated
## Tips for Optimal Results
1. **Be Comprehensive**: Don't just find one file, map the entire flow
2. **Provide Context**: Explain why code is structured this way
3. **Show Examples**: Include actual code snippets
4. **Think Holistically**: Connect related pieces across files
5. **Anticipate Questions**: Answer follow-up questions proactively
## Integration with Other Tools
This Skill works well with:
- **claudemem CLI**: For local semantic code search with Tree-sitter parsing
- **MCP gopls**: For Go-specific analysis
- **Standard CLI tools**: grep, ripgrep, find, git
- **Project-specific tools**: Use project's search/navigation tools
## Notes
- The codebase-detective agent uses extended thinking for complex analysis
- **claudemem is REQUIRED** - grep/find produce inferior results
- Fallback to grep ONLY if claudemem unavailable AND user accepts degraded mode
- claudemem requires OpenRouter API key (https://openrouter.ai)
- Default model: `voyage/voyage-code-3` (best code understanding)
- Run `claudemem --models` to see all options and pricing
- Results are actionable and navigable
- Great for onboarding to new codebases
- Helps prevent incorrect assumptions about code
## Tool Selection Quick Reference
┌─────────────────────────────────────────────────────────────────────┐ │ BEFORE ANY CODE INVESTIGATION: │ │ │ │ 1. INVOKE code-search-selector skill │ │ 2. Run: claudemem status │ │ 3. If indexed → USE claudemem search │ │ 4. If not indexed → Index first OR ask user │ │ 5. NEVER default to grep when claudemem available │ │ 6. NEVER start with Read/Glob for semantic questions │ │ │ │ grep is for EXACT STRING MATCHES only, NOT semantic understanding │ └─────────────────────────────────────────────────────────────────────┘
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**Maintained by:** tianzecn
**Plugin:** code-analysis v2.2.0
**Last Updated:** December 2025