drawio-engineering-mcp

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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

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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.

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Quick start

Install

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

Three surfaces, same answer

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Claude Code

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

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Claude Desktop

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

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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.

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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

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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"]
}

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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.

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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.

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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

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Based on

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

Contributing

Contributions are welcome.

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

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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.

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_{Part of <a href="https://github.com/RFingAdam/eng-mcp-suite">eng-mcp-suite</a> — built for RF engineers, PCB designers, EMC labs, and AI agents.}

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