D2 MCP Server

D2 MCP Server

A Model Context Protocol (MCP) server that provides D2 diagram generation and manipulation capabilities.

D2 is a modern diagram scripting language that turns text to diagrams. This MCP server allows AI assistants like Claude to create, render, export, and save D2 diagrams programmatically.

The server provides 16 MCP tools for complete-source authoring, validation, rendering, embedded D2 guidance, and incremental Oracle editing.

With the new Oracle API integration, AI assistants can now build and modify diagrams incrementally, making it perfect for:

• Converting conversations into architecture diagrams
• Building flowcharts step-by-step as requirements are discussed
• Creating entity relationship diagrams from database schemas
• Generating system diagrams from code analysis
• Refining diagrams based on user feedback without starting over

Features

Source-First Diagram Operations

• d2create** - Create diagrams from complete D2 source or start empty
• d2getsource - Retrieve the canonical source, including Oracle edits
• d2updatesource - Validate then atomically replace complete source
• d2format** - Format valid source without storing it
• d2validate** - Validate raw or stored source and suggest conservative repairs
• d2export** - Export with bundled D2 v0.9 renderers (SVG, PNG, PDF, PPTX, GIF, ASCII)
• d2save** - Save an export inside a configured workspace root
• d2help** - Search or retrieve embedded D2 v0.9 guidance
• d2capabilities** - List the versioned capability catalog

Oracle API for Incremental Editing

• d2oraclecreate - Create shapes and connections incrementally
• d2oracleset - Set attributes on existing elements
• d2oracledelete - Delete specific elements from diagrams
• d2oraclemove - Move shapes between containers
• d2oraclerename - Rename diagram elements
• d2oraclegetinfo** - Get information about shapes, connections, or containers
• d2oracleserialize - Get the current D2 text representation of the diagram

Additional Features

• Bundled layouts - Dagre, ELK, and TALA
• Typed rendering - Layout, theme overrides, bundled fonts, scale, padding, sketch, animation, board selection, and bounded output options
• 20 themes - Support for all D2 themes (18 light + 2 dark)

Project Structure

d2mcp/
├── cmd/                  # Application entry point
├── internal/
│   ├── domain/          # Business entities and interfaces
│   │   ├── entity/      # Domain entities
│   │   └── repository/  # Repository interfaces
│   ├── usecase/         # Business logic
│   ├── infrastructure/  # External implementations
│   │   ├── d2/          # D2 library integration
│   │   └── mcp/         # MCP server implementation
│   └── presentation/    # MCP handlers
│       └── handler/     # Tool handlers
└── pkg/                 # Public packages

Prerequisites

• Go 1.27 or higher
• D2 v0.9.0 (included as a Go dependency)

All export formats use bundled Go renderers; no rsvg-convert, ImageMagick, or Chromium installation is required.

The embedded capability catalog is based on the official D2 language tour, D2 API documentation, and D2 v0.9.0 release.

Installation

From Source

# Clone the repository
git clone https://github.com/recursivefunctions/d2mcp.git
cd d2mcp

# Build the binary
make build

# Or build for all platforms
make build-all

Using Go Install

go install github.com/recursivefunctions/d2mcp/cmd@latest

Using Docker

docker run --rm -i \
  --mount type=bind,src="$PWD",dst=/workspace \
  ghcr.io/recursivefunctions/d2mcp:0.5.0

Shortened. The full README is on GitHub.