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

Architecture Diagram

Generate a Mermaid flowchart showing high-level component relationships in a codebase.

When To Use

• Visualizing how plugins/modules relate to each other
• Onboarding to understand system structure
• Documenting architecture for PR reviews
• Answering "how does this system fit together?"

Workflow

Step 1: Explore the Codebase

Dispatch the codebase explorer agent to analyze the scope:

Agent(cartograph:codebase-explorer)
Prompt: Explore [scope] and return a structural model.
Focus on packages, modules, and their relationships
for an architecture diagram.

If no scope is provided, use the project root.

Step 2: Generate Mermaid Syntax

Transform the structural model into a Mermaid flowchart.

Rules for architecture diagrams:

• Use

  flowchart TD

  (top-down) for hierarchical systems
• Use

  flowchart LR

  (left-right) for pipeline/flow systems
• Group related modules into subgraphs by package
• Use descriptive edge labels for relationships
• Limit to 15-20 nodes maximum (aggregate small modules)
• Use shapes to distinguish component types:

  • [Rectangle]

    for modules/packages

  • ([Stadium])

    for entry points/commands

  • [(Database)]

    for data stores

  • {Diamond}

    for decision points

Example output:

flowchart TD
    subgraph sanctum[Sanctum Plugin]
        commit[Commit Messages]
        pr[PR Preparation]
        workspace[Workspace Review]
    end

    subgraph leyline[Leyline Plugin]
        git[Git Platform]
        patterns[Error Patterns]
    end

    commit --> git
    pr --> workspace
    pr --> git
    workspace --> patterns

Step 3: Render via MCP

Call the Mermaid Chart MCP to render:

mcp__claude_ai_Mermaid_Chart__validate_and_render_mermaid_diagram
  prompt: "Architecture diagram of [scope]"
  mermaidCode: [generated syntax]
  diagramType: "flowchart"
  clientName: "claude-code"

If rendering fails, fix the Mermaid syntax based on the error message and retry (max 2 retries).

Step 4: Present Results

Show the rendered diagram to the user with a brief summary of what it depicts (2-3 sentences).