drawio-engineering-mcp

A Model Context Protocol server that gives Claude (and other LLMs) the ability to create, view, and analyze engineering diagrams in draw.io.
Built on the official draw.io MCP, extended with 10 tools and 269 drag-and-drop engineering symbols
covering RF, electrical, PCB, EMC, wireless, and general engineering.

---

Quick Start

1. Install

git clone https://github.com/RFingAdam/drawio-engineering-mcp.git
cd drawio-engineering-mcp
npm install

2. Add to Claude Code

claude mcp add drawio-engineering -s user -- node /path/to/drawio-engineering-mcp/src/index.js

3. Add to Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "drawio-engineering": {
      "command": "node",
      "args": ["/path/to/drawio-engineering-mcp/src/index.js"]
    }
  }
}

4. Verify

Start a new Claude session. You should see 10 tools available:

open_drawio_xml, open_drawio_csv, open_drawio_mermaid, open_drawio_engineering,
create_rf_block_diagram, create_emc_test_setup, create_pcb_stackup,
markup_schematic, read_drawio, export_drawio

---

Tools

Viewer / Editor Tools

Tool	Description
open_drawio_xml	Open draw.io with XML content
open_drawio_csv	Open draw.io with CSV data
open_drawio_mermaid	Open draw.io with Mermaid syntax
open_drawio_engineering	Open draw.io with 269 engineering stencils loaded in sidebar

Generator Tools

Tool	Description
create_rf_block_diagram	Auto-layout RF signal chain from JSON (gain/NF cascade, Friis formula)
create_emc_test_setup	CISPR 25 / ISO 11452 EMC test setup diagrams from templates
create_pcb_stackup	PCB cross-section stackup diagrams (4-layer, 6-layer, custom)
markup_schematic	Annotate schematic screenshots with redlines, revision clouds, callouts

Analysis Tools

Tool	Description
read_drawio	Parse .drawio files into structured JSON (shapes, edges, styles)
export_drawio	Export diagrams to SVG (or PNG with puppeteer)

---

Usage Examples

RF Signal Chain

Ask Claude:

"Create an RF receiver signal chain with antenna, SAW filter, LNA, mixer with PLL LO, IF filter, and ADC. Show cumulative gain and noise figure."

The create_rf_block_diagram tool generates a color-coded, auto-laid-out diagram with Friis cascade annotations.

EMC Test Setup

"Show me a CISPR 25 radiated emissions test setup"

Uses create_emc_test_setup with the cispr25_re template. Also supports cispr25_ce, iso11452_2_ri, and iso11452_4_ci.

PCB Stackup

"Generate a 6-layer PCB stackup with Rogers 4003C for the RF layers"

The create_pcb_stackup tool renders color-coded cross-sections with material properties and impedance annotations.

Engineering Diagrams with Stencils

"Open draw.io with the RF and PCB stencils loaded — I need to draw an antenna matching network"

Uses open_drawio_engineering which loads stencil libraries into the draw.io sidebar for drag-and-drop.

Schematic Markup

"Here's a screenshot of my schematic. Circle the decoupling caps that need to be moved closer to the IC, and add a note about the missing ferrite bead."

The markup_schematic tool overlays annotations on the image as a locked background layer.

---

Stencil Libraries

269 symbols across 13 libraries, automatically loaded in the draw.io sidebar:

Library	Symbols	Contents
rf-blocks	30	Core RF blocks (LNA, PA, mixer, filter, switch, antenna, etc.)
rf-amplifiers-mixers	16	Amplifier variants (LNA, PA, VGA, driver, buffer, log, limiting) + mixers
rf-filters-attenuators	17	BPF, LPF, HPF, notch, cavity, SAW, BAW, DSA, step/variable atten
rf-passive-components	14	Circulators, isolators, directional couplers, Wilkinson, hybrid, balun
rf-sources-oscillators	10	Crystal, TCXO, OCXO, VCO, PLL, DDS, synthesizer
rf-switches-detectors	15	SPDT, SP4T, transfer, T/R, power detector, ADC, DAC
rf-antennas-txlines	20	Dipole, patch, horn, array, MIMO, coax, microstrip, waveguide
ee-power-ics	20	LDO, buck, boost, flyback, battery, SoC, FPGA, MCU, QFN, BGA
ee-connectors	14	SMA, U.FL, N-type, BNC, USB-C, RJ45, pin header, B2B
ee-test-equipment-emc	18	Spectrum analyzer, VNA, scope, LISN, CDN, anechoic chamber
pcb-stackup-vias	30	Copper/prepreg/core layers, through/blind/buried/micro vias, impedance traces
wireless-telecom	27	WiFi, BLE, LTE, 5G NR, LoRa, Zigbee, Thread, protocol badges, OFDM, QAM
general-engineering	38	System blocks, rack diagrams, cables, thermal management, R/L/C/transformer

Loading Specific Libraries

By default, all libraries load. To load only specific ones:

{
  "stencils": ["rf-blocks", "ee-connectors", "pcb-stackup-vias"]
}

---

Project Structure

drawio-engineering-mcp/
├── src/
│   ├── index.js                    # MCP server entry point
│   ├── core/
│   │   ├── compression.js          # pako deflate + base64 URL generation
│   │   ├── browser.js              # Cross-platform browser opener
│   │   └── xml-builder.js          # Fluent XML builder for mxGraphModel
│   ├── tools/
│   │   ├── open-xml.js             # open_drawio_xml
│   │   ├── open-csv.js             # open_drawio_csv
│   │   ├── open-mermaid.js         # open_drawio_mermaid
│   │   ├── open-engineering.js     # open_drawio_engineering (stencil loader)
│   │   ├── create-rf-block-diagram.js
│   │   ├── create-emc-test-setup.js
│   │   ├── create-pcb-stackup.js
│   │   ├── markup-schematic.js
│   │   ├── read-drawio.js
│   │   └── export-drawio.js
│   ├── generators/
│   │   ├── rf-signal-chain.js      # RF cascade layout + Friis calculations
│   │   ├── emc-setup.js            # EMC test setup diagram generation
│   │   ├── pcb-stackup.js          # PCB cross-section rendering
│   │   └── layout.js               # Shared layout utilities
│   └── data/
│       ├── rf-components.json      # Default gain/NF/P1dB for RF components
│       ├── emc-standards.json      # CISPR/ISO template definitions
│       └── pcb-materials.json      # Dk/Df for FR-4, Rogers, Megtron, etc.
├── docs/
│   └── stencils/                   # 13 XML stencil library files (269 symbols)
├── package.json
├── LICENSE                         # Apache 2.0
└── README.md

Based On

Extended from the official draw.io MCP server (@drawio/mcp) by JGraph Ltd.

License

Apache 2.0