Night Market Skill — ported from claude-night-market/cartograph. For the full experience with agents, hooks, and commands, install the Claude Code plugin.

Code Community Detection#

Identify architectural clusters and module boundaries in the codebase.

Prerequisites#

This skill requires the gauntlet plugin for graph data. Discover it:

bash

GRAPH_QUERY=$(find ~/.claude/plugins -name "graph_query.py" -path "*/gauntlet/*" 2>/dev/null | head -1)

If gauntlet is not installed: Fall back to directory structure analysis. Group files by directory and use import statements to identify module boundaries. Generate a Mermaid diagram from directory-level relationships.

If installed but no graph.db: Tell the user to run /gauntlet-graph build.

Steps#

1. Run community detection (requires gauntlet): bash

   python3 "$GRAPH_QUERY" --action communities
   
   

   Fallback (no gauntlet): Analyze directory structure and cross-directory imports: bash

   # Directory-level grouping
   find . -name "*.py" -not -path "*/node_modules/*" | \
       sed 's|/[^/]*$||' | sort | uniq -c | sort -rn
   
   # Cross-directory imports (rg preferred, grep fallback)
   if command -v rg &>/dev/null; then
     rg "^from |^import " --type py -l . | \
       xargs -I{} rg "^from \w+ import|^import \w+" {} --no-filename
   else
     grep -rh "^from \|^import " --include="*.py" .
   fi | sort | uniq -c | sort -rn | head -20
   
   

   Group by top-level directories and count cross-directory imports to estimate coupling.

2. Display clusters: text

   Community         | Nodes | Cohesion | Description
   auth              |    12 |    0.85  | Authentication module
   db                |     8 |    0.92  | Database access layer
   api/handlers      |    15 |    0.71  | API request handlers
   utils             |     6 |    0.45  | Shared utilities
   
   

3. Show coupling warnings: If communities have

   10 cross-boundary edges, highlight them:

   text

   WARNING: High coupling between 'auth' and 'api/handlers'
   (23 cross-community edges, severity: high)
   
   

4. Generate Mermaid diagram:

   Rendering diagram...

5. Suggest improvements:

   • Low cohesion (<0.5): "Consider splitting this module into more focused components"
   • High coupling (>20 edges): "Consider introducing an interface to reduce direct dependencies"

Algorithm#

Uses the Leiden algorithm (when igraph is available) with edge-type-specific weights. Falls back to file-based grouping otherwise.

Edge TypeWeightCALLS1.0INHERITS0.8IMPLEMENTS0.7IMPORTS_FROM0.5TESTED_BY0.4CONTAINS0.3