Engineering diagrams in draw.io — RF block diagrams, PCB stackups, and EMC test setups generated from structured prompts.
Drive it from your IDE, terminal, or AI agent and skip the manual stencil-dragging.

Quick start ·
Tools ·
Workflows ·
Documentation

What is drawio-engineering-mcp?

drawio-engineering-mcp is a Node.js MCP server that gives an AI agent
the ability to create, view, and analyze engineering diagrams in
draw.io. It extends the
official draw.io MCP (@drawio/mcp)
with 10 tools and 269 drag-and-drop engineering symbols across RF,
PCB, EMC, wireless, electrical, and general engineering.

Where the upstream MCP gives you a diagram editor, this one gives you a
diagram generator: an RF receiver signal chain with Friis-cascade
annotations, a CISPR 25 / ISO 11452 test setup, a 6-layer PCB stackup
with material-property labels — all from a one-sentence prompt or
structured JSON input.

What it does well:

🤖 AI-native via MCP. First-class Model Context Protocol
server with 10 tools wired into the draw.io browser app.
🎨 269 engineering stencils. RF blocks, amplifiers, filters,
antennas, PCB stackup vias, EMC test equipment, wireless protocol
badges, connectors, power ICs — all auto-loaded into the draw.io sidebar.
⚡ Auto-layout generators. create_rf_block_diagram runs Friis
gain/NF cascade math; create_pcb_stackup renders cross-sections
with material properties; create_emc_test_setup uses CISPR / ISO
templates.
✅ Round-trip. read_drawio parses .drawio XML into structured
JSON (shapes, edges, styles) so an agent can analyze an existing
diagram. export_drawio renders to SVG / PNG.
🔒 AGPL-3.0-or-later. Built on the official draw.io MCP foundation
(Apache-2.0); this server's engineering extensions are AGPL-3.0-or-later.

Quick start

Install

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

Three surfaces, same answer

Claude Code

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

Claude Desktop

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

Any MCP client — first prompt

Start a new session and ask:

"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 agent calls create_rf_block_diagram and opens draw.io with a
color-coded, auto-laid-out diagram annotated with Friis cascade values.

Tools

10 MCP tools across 3 categories. Full reference in docs/tools.md.

Viewer / editor

Tool	Purpose	Key arguments
`open_drawio_xml`	Open draw.io with raw XML content	`xml`
`open_drawio_csv`	Open draw.io with CSV data	`csv`, `style`
`open_drawio_mermaid`	Open draw.io with Mermaid syntax	`mermaid`
`open_drawio_engineering`	Open draw.io with the 269 engineering stencils loaded in the sidebar	`stencils`

Generators

Tool	Purpose	Key arguments
`create_rf_block_diagram`	Auto-layout RF signal chain from JSON (Friis gain/NF cascade)	`blocks`, `frequency_ghz`
`create_emc_test_setup`	CISPR 25 / ISO 11452 EMC test setup diagrams from templates	`template`, `dut_name`
`create_pcb_stackup`	PCB cross-section stackup diagrams (4-layer / 6-layer / custom)	`layers`, `materials`
`markup_schematic`	Annotate schematic screenshots with redlines, revision clouds, callouts	`image_path`, `annotations`

Analysis

Tool	Purpose	Key arguments
`read_drawio`	Parse `.drawio` files into structured JSON (shapes, edges, styles)	`file_path`
`export_drawio`	Export diagrams to SVG (or PNG with puppeteer)	`file_path`, `format`

Stencil libraries

269 engineering symbols across 13 libraries, automatically loaded by
open_drawio_engineering into the draw.io sidebar:

Library	Symbols	Contents
`rf-blocks`	30	Core RF blocks (LNA, PA, mixer, filter, switch, antenna, …)
`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	Wi-Fi, 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

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

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

Workflows

drawio-engineering-mcp fits in the following eng-mcp-suite
workflow bundles:

emc-compliance — pair create_emc_test_setup with
mcp-emc-regulations to generate the test setup diagram for the
exact CISPR / ISO method the limit lookup returned.
pcb-review — generate create_pcb_stackup cross-sections during
a mcp-pcb-emcopilot design review.
rf-design — use create_rf_block_diagram to visualize the
cascade an LNA / mixer / filter chain produces — Friis numbers
annotated automatically.

Part of eng-mcp-suite.
Use in the emc-compliance, pcb-review, or rf-design workflow bundles.

See the suite manifest
for the full list of sibling MCPs and bundle definitions.

Documentation

📘 Quick Start — install through first call.
🛠️ Tool reference — every MCP tool, every argument.
📐 Usage examples — practical end-to-end walkthroughs.
🏗️ Architecture — how this MCP fits in eng-mcp-suite.

Part of eng-mcp-suite

_{This MCP server is part of}

_{An open umbrella for engineering MCP servers across RF, EMC, PCB,
signal integrity, EM simulation, and lab test. Same brand, same docs
structure, designed to compose. See the
full catalog
or jump to a sibling:}

Domain	Sibling MCPs
RF / Transmission lines	lineforge
EMC regulatory	mcp-emc-regulations
PCB / SI	mcp-pcb-emcopilot (private — public soon)
EM simulation	mcp-openems, mcp-nec2-antenna (private — public soon)
Diagrams	drawio-engineering-mcp (this repo)
3D / rendering	mcp-blender
Remote access	mcp-remote-access
Lab gear	copper-mountain-vna-mcp, mcp-rs-spectrum-analyzer, mcp-rs-siggen, mcp-rs-cmw500

Based on

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

Contributing

Contributions are welcome.

Pick a GitHub issue.
Fork + branch (feature/your-thing or fix/your-bug).
Run tests (npm test) if present.
Open a PR — link the issue, request review.

License

AGPL-3.0-or-later. Relicensed from Apache-2.0 in v1.1.0 to
align with the eng-mcp-suite toolkit-wide AGPL move. The upstream
draw.io MCP foundation remains Apache-2.0; this server's engineering
extensions and added tooling are AGPL-3.0-or-later.

Acknowledgments

JGraph Ltd / draw.io — for the
upstream @drawio/mcp and the underlying diagram editor.
The MCP working group — for the Model Context Protocol specification.

_{Part of eng-mcp-suite — built for RF engineers, PCB designers, EMC labs, and AI agents.}