knowledge-graph-visualizer

name	knowledge-graph-visualizer
version	1.0.0
description	Transform a knowledge graph into Mermaid diagrams for architecture visualization, dependency mapping, and data flow analysis.
author	iscmga
tags	["visualization","mermaid","diagrams","knowledge-graph","architecture","dependencies"]
triggers	{"globs":["**/knowledge-graph.json","**/docs/diagrams/*.md"],"keywords":["visualize","diagram","mermaid","graph diagram","architecture diagram","dependency diagram","show knowledge graph"]}

Knowledge Graph Visualizer

Transform .understand/knowledge-graph.json into Mermaid diagrams that render natively in GitHub, GitLab, Obsidian, and most markdown viewers. Produces architecture overviews, dependency graphs, data flow maps, and file organization trees.

When to Activate

• After running codebase-understanding (knowledge graph exists)
• "Show me a diagram of this codebase"
• "Visualize the architecture"
• "Generate dependency diagrams"
• "Draw the knowledge graph"
• As part of the repo-augmentation pipeline (Stage 1.75, alongside docs-generation)

Prerequisites

• .understand/knowledge-graph.json must exist. Run codebase-understanding first if it doesn't.

Output Structure

docs/
└── diagrams/
    ├── README.md              # Index of all diagrams with descriptions
    ├── architecture.md        # Layer overview diagram
    ├── dependencies.md        # Module dependency graph
    ├── data-flow.md           # How data flows through the system
    └── file-map.md            # File organization treemap

Pipeline — 6 Steps

Step 1: READ knowledge graph
         |
Step 2: GENERATE docs/diagrams/architecture.md
         |
Step 3: GENERATE docs/diagrams/dependencies.md
         |
Step 4: GENERATE docs/diagrams/data-flow.md
         |
Step 5: GENERATE docs/diagrams/file-map.md
         |
Step 6: GENERATE docs/diagrams/README.md (index)

Step 1: Read Knowledge Graph

Load .understand/knowledge-graph.json and extract:

layers[]     → for architecture diagram
nodes[]      → for all diagrams (files, classes, functions)
edges[]      → for dependency and data-flow diagrams
tour[]       → for highlighting entry points
metadata     → for labels and titles

Step 2: Generate docs/diagrams/architecture.md

A top-down view of architectural layers and their relationships.

# Architecture Overview

> Auto-generated from knowledge graph. Commit: `<hash>`

## Layer Diagram

```mermaid
flowchart TD
    subgraph <Layer1>[" <Layer1 Name> — <description snippet> "]
        L1F1["<top file 1>"]
        L1F2["<top file 2>"]
        L1F3["<top file 3>"]
    end

    subgraph <Layer2>[" <Layer2 Name> — <description snippet> "]
        L2F1["<top file 1>"]
        L2F2["<top file 2>"]
    end

    <Layer1> --> <Layer2>
    <Layer2> --> <Layer3>
`` `

## Layer Details

| Layer | Files | Description |
|-------|-------|-------------|
| <name> | <count> | <description> |

Construction rules:

• One subgraph per layer from layers[]
• Show top 3-5 files per layer (by edge count — most connected first)
• Draw edges between subgraphs based on cross-layer imports/calls/depends_on edges
• Use --> for direct dependencies, -.-> for weak/optional dependencies
• Add brief descriptions in subgraph labels
• If a layer has >10 files, add a ...and N more node

Step 3: Generate docs/diagrams/dependencies.md

A graph showing how modules/files depend on each other.

# Dependency Graph

> Shows import and dependency relationships between key files.

## Full Dependency Graph

```mermaid
graph LR
    A["src/index.ts"] --> B["src/routes/api.ts"]
    A --> C["src/config/db.ts"]
    B --> D["src/services/userService.ts"]
    B --> E["src/services/postService.ts"]
    D --> F["src/models/User.ts"]
    E --> F
    E --> G["src/models/Post.ts"]

    style A fill:#f9f,stroke:#333
    style F fill:#bbf,stroke:#333
`` `

Construction rules:

• Include only imports, calls, depends_on, and routes_to edge types
• Filter to top 30-40 most-connected nodes to keep the diagram readable
• If the graph has >40 nodes, generate per-layer subgraphs instead of one flat graph
• Use graph LR (left-to-right) for dependency flow
• Style entry points with a distinct fill color (pink/highlighted)
• Style high-complexity nodes with a warning color
• Add a legend section explaining the colors

Per-layer variant (for large codebases):

If total nodes > 40, generate additional focused diagrams:

## <Layer Name> Dependencies

```mermaid
graph LR
    %% Only nodes in <Layer> and their direct dependencies
    ...
`` `

Step 4: Generate docs/diagrams/data-flow.md

Shows how data moves through the system.

# Data Flow

> How data enters, transforms, and exits the system.

## Request Flow

```mermaid
flowchart LR
    Client([Client]) --> Entry["Entry Point<br/><entry file>"]
    Entry --> Router["Router<br/><router file>"]
    Router --> Service["Service Layer<br/><service file>"]
    Service --> Data["Data Layer<br/><model/db file>"]
    Data --> DB[(Database)]

    Service --> External["External API<br/><integration file>"]
`` `

Construction rules:

• Use flowchart LR for left-to-right data flow
• Start from entry points (tour step 1, or highest fan-out nodes)
• Follow imports → calls → reads_from/writes_to edge chains
• Use special shapes:
  • ([...]) for external actors (Client, User)
  • [(...)] for databases
  • ["..."] for internal components
  • {{"..."}} for decision points
• Group related nodes if they form a pipeline
• Add :::className for styling if needed
• If the system has multiple entry points (e.g., HTTP + cron + queue), show each as a separate flow

Event-driven variant:

If subscribes/publishes edges are present:

## Event Flow

```mermaid
flowchart TD
    Publisher["<publisher file>"] -->|publishes| EventBus{{Event Bus}}
    EventBus -->|subscribes| HandlerA["<handler A>"]
    EventBus -->|subscribes| HandlerB["<handler B>"]
`` `

Step 5: Generate docs/diagrams/file-map.md

A treemap/hierarchy showing file organization.

# File Organization

> Directory structure with architectural layer annotations.

## File Tree

```mermaid
flowchart TD
    Root["<project-name>/"]
    Root --> Src["src/"]
    Root --> Config["config/"]
    Root --> Tests["tests/"]

    Src --> SrcAPI["api/ <br/> 🔵 API Layer"]
    Src --> SrcSvc["services/ <br/> 🟢 Service Layer"]
    Src --> SrcData["models/ <br/> 🟡 Data Layer"]

    SrcAPI --> API1["routes.ts"]
    SrcAPI --> API2["middleware.ts"]

    SrcSvc --> Svc1["userService.ts"]
    SrcSvc --> Svc2["postService.ts"]

    SrcData --> Data1["User.ts"]
    SrcData --> Data2["Post.ts"]
`` `

Construction rules:

• Use flowchart TD (top-down) for tree hierarchy
• Group files by directory, then annotate with layer assignment
• Use emoji color indicators for layers:
  • 🔵 API
  • 🟢 Service
  • 🟡 Data
  • 🟣 UI
  • ⚙️ Config
  • 🧪 Testing
  • 🏗️ Infrastructure
• Show individual files only for directories with ≤8 files
• For larger directories, show count: "controllers/ (15 files)"
• Max depth: 3 levels (project → directory → subdirectory)

Step 6: Generate docs/diagrams/README.md

Index page linking all diagrams:

# Diagrams

> Visual representations of the **<project name>** codebase.
> Generated from knowledge graph at commit `<hash>`.

## Available Diagrams

| Diagram | Description | Best For |
|---------|-------------|----------|
| [Architecture Overview](architecture.md) | Layer diagram showing system structure | Understanding the big picture |
| [Dependency Graph](dependencies.md) | Import/call relationships between files | Finding coupling and dependencies |
| [Data Flow](data-flow.md) | How data moves through the system | Understanding request/event lifecycle |
| [File Map](file-map.md) | Directory structure with layer annotations | Navigating the codebase |

## How to View

These diagrams use [Mermaid](https://mermaid.js.org/) syntax which renders natively in:
- GitHub / GitLab markdown preview
- Obsidian
- VS Code (with Mermaid extension)
- Notion (paste as code block, select Mermaid)

For other viewers, paste the mermaid code blocks into [mermaid.live](https://mermaid.live/).

Mermaid Best Practices

Follow these rules to keep diagrams renderable and readable:

Size Limits

• Max 50 nodes per diagram. Beyond that, split into sub-diagrams.
• Max 3 nesting levels for subgraphs.
• Node labels under 40 characters. Truncate file paths: src/services/userService.ts → userService.ts (show full path in a table below the diagram).

Syntax Safety

• Quote all node labels with ["..."] to avoid Mermaid parsing errors.
• Avoid special characters in node IDs — use alphanumeric + underscores only.
• Sanitize file names for IDs: src/api/routes.ts → src_api_routes_ts.
• Test each diagram mentally — if it has syntax errors, Mermaid renders nothing.

Readability

• Use graph LR for dependency/flow diagrams (left-to-right reads naturally).
• Use flowchart TD for hierarchies and architecture (top-down).
• Add spacing with empty lines between subgraph blocks.
• Use style directives sparingly — only for entry points and high-complexity nodes.
• Include a legend/key if colors or shapes have meaning.

Node ID Convention

Generate deterministic IDs from file paths:

File path:  src/api/routes.ts
Node ID:    src_api_routes_ts
Label:      ["routes.ts"]

This ensures:

• No ID collisions
• Reproducible diagrams on regeneration
• Valid Mermaid syntax (no dots or slashes in IDs)

Incremental Updates

Same strategy as docs-generation:

1. Check if docs/diagrams/ exists
2. Compare commit hash in docs/diagrams/README.md with current knowledge graph
3. If different → regenerate all diagrams
4. If same → skip

Quality Checks

Before finalizing:

• All 4 diagram files + README exist in docs/diagrams/
• Each Mermaid code block is syntactically valid (no unclosed quotes, balanced brackets)
• No diagram exceeds 50 nodes
• Architecture diagram has one subgraph per layer
• Dependency diagram includes only the most-connected nodes
• Data flow diagram starts from an entry point
• File map depth does not exceed 3 levels
• All node IDs are sanitized (no special characters)
• README index links are valid

Anti-Patterns

• Giant hairball graphs: A 200-node dependency diagram is useless. Filter aggressively — show the top 30-40 most important nodes.
• Unlabeled diagrams: Every diagram needs a title, description, and context about what it shows.
• Syntax errors: One bad character and the entire Mermaid block fails to render. Always sanitize IDs and quote labels.
• Redundant diagrams: Don't generate 4 diagrams that show the same thing differently. Each diagram has a distinct purpose.
• Static screenshots: Never generate image files. Mermaid is text-based and diff-friendly — that's the whole point.
• Ignoring the knowledge graph: Don't read source files to build diagrams. The knowledge graph is the single source of truth.

Integration Points

With docs-generation skill

Run alongside docs-generation. The docs can link to diagrams, and diagrams link back to docs:

• docs/architecture.md can embed or link to docs/diagrams/architecture.md
• docs/modules/<layer>.md can link to the relevant subgraph in the dependency diagram

With codebase-understanding skill

This skill REQUIRES the knowledge graph as input. Always run codebase-understanding first.

With repo-augmentation skill

Slots in as Stage 1.75 alongside docs-generation. The updated pipeline:

1. Understand → knowledge-graph.json
2. Document → docs/ (prose)
3. Visualize → docs/diagrams/ (Mermaid)
4. Equip → install relevant skills
5. Generate → CLI