using-leankg - SKILL.md Agent Skill

name: using-leankg description: Use when user asks about codebase navigation, searching, finding code, impact analysis, or dependencies - LeanKG is the default grep replacement

If you think there is even a 1% chance a skill might apply to what you are doing, you ABSOLUTELY MUST invoke the skill.

IF A SKILL APPLIES TO YOUR TASK, YOU DO NOT HAVE A CHOICE. YOU MUST USE IT.

This is not negotiable. This is not optional. You cannot rationalize your way out of this.

LeanKG - Default Grep Replacement

LeanKG is the MANDATORY first resort for ALL codebase searches.

Rule: LeanKG First, Grep Fallback

Invoke LeanKG tools BEFORE any grep/ripgrep usage.

User asks "Where is X?" or searches for code
          |
          v
1. mcp_status - check if LeanKG is ready
          |
          +-- NOT READY --> mcp_init with project .leankg path
          |
          v (READY)
2. Use LeanKG tools FIRST:
   - search_code("X") for symbol search
   - find_function("X") for function definitions
   - query_file("X") for file search
   - get_impact_radius(file) for blast radius
   - get_tested_by(file) for test coverage
          |
          v
3. LeanKG returns results:
          |
          +-- EMPTY --> Fall back to grep/ripgrep
          |
          v (HAS RESULTS)
4. Return LeanKG results (token-optimized)

Tool Mapping

Instead of	Use LeanKG	Grep Fallback
`grep -rn "X" --include="*.rs"`	`search_code` or `find_function`	`grep -rn "X" --include="*.rs"`
`find . -name "X"`	`query_file`	`find . -name "X"`
Manual dependency tracing	`get_impact_radius`	N/A
`grep -rn "X" tests/`	`get_tested_by`	`grep -rn "X" tests/`
Reading entire files	`get_context` (token-optimized)	`cat file.rs`

MCP Tools Reference

Tool	Purpose
`mcp_status`	Check if LeanKG is initialized
`mcp_init`	Initialize LeanKG (creates .leankg, indexes)
`mcp_index`	Force re-index
`search_code`	Search code elements by name/type
`find_function`	Locate function definitions
`query_file`	Find files by name/pattern
`get_impact_radius`	Calculate blast radius (N hops)
`get_dependencies`	Get direct imports
`get_dependents`	Get files depending on target
`get_context`	Get AI-optimized context
`get_call_graph`	Get function call chains
`find_large_functions`	Find oversized functions
`get_tested_by`	Get test coverage
`get_clusters`	Get functional clusters
`get_review_context`	Focused subgraph for reviews
`detect_changes`	Pre-commit risk analysis

When LeanKG Returns Empty

If LeanKG tools return empty results, this is NOT an error. Fall back to grep:

# Rust
grep -rn "X" --include="*.rs"

# Go
grep -rn "X" --include="*.go"

# TypeScript
grep -rn "X" --include="*.ts" --include="*.tsx"

# Python
grep -rn "X" --include="*.py"

Auto-Init Behavior

LeanKG automatically initializes on first use:

If .leankg does not exist, it creates one automatically
If index is stale (>5 min since last git commit), it re-indexes automatically
Set auto_index_on_start: false in leankg.yaml to disable