Wiring Diagram MCP Server
Give Claude, Cursor, or any MCP client the ability to generate 12V/24V/48V wiring diagrams and size wires, fuses, batteries, solar, and inverters — for campers, boats, and off-grid systems. Hosted, free, and no install: just add one URL.
https://mcp.voltplan.app/mcpNo install · No API key · MIT licensed · Works with Claude, Cursor, Cline
What the Wiring Diagram MCP does
VoltPlan is an electrical system designer for low-voltage DC installs. The MCP server exposes the same engine to your AI assistant: describe a system in plain language and the assistant calls the right tools to size every cable, pick fuses, plan the battery and solar side, and render a finished wiring diagram. Unlike a generic diagramming MCP, it knows the electrical math — a 2000 W inverter at 12V draws ~170 A, so the cable to the battery must be 2 AWG (35 mm²) or heavier with a 200 A Class T fuse near the positive terminal. It works that out for you.
Connect your client
The server is hosted at https://mcp.voltplan.app/mcp over HTTP. Add that URL to your client — there is nothing to install. Pick yours below, then restart the client.
Claude Code
One command from the terminal.
claude mcp add wiring-diagram \
--transport http https://mcp.voltplan.app/mcpClaude Desktop
Add to claude_desktop_config.json.
{
"mcpServers": {
"wiring-diagram": {
"url": "https://mcp.voltplan.app/mcp"
}
}
}Cursor
Add to ~/.cursor/mcp.json.
{
"mcpServers": {
"wiring-diagram": {
"url": "https://mcp.voltplan.app/mcp"
}
}
}Cline & other clients
Any client with remote-MCP support uses the same URL and HTTP transport.
url: https://mcp.voltplan.app/mcp
transport: httpPrefer to run it locally or self-host? The GitHub repo has npx and self-hosted instructions.
Tools the MCP exposes
Nine tools cover sizing and rendering, served by the wiring-diagram server.
| tool | does |
|---|---|
| generate_wiring_diagram | Render a complete 12V/24V/48V wiring diagram (PNG or SVG) from batteries, loads, chargers, and solar arrays. |
| calculate_wire_gauge | Recommend AWG / mm² wire size, voltage drop, and matching fuse for a single DC circuit. |
| calculate_battery_bank | Size a battery bank from daily energy demand, days of autonomy, and depth of discharge. |
| calculate_battery_config | Work out a series/parallel topology of cells or batteries for a target voltage and capacity. |
| calculate_charging_time | Estimate charge time from a charger or solar array against a battery bank. |
| calculate_inverter_size | Recommend an inverter size from AC load profile, surge needs, and system voltage. |
| calculate_power_budget | Build a 24h power budget from a load list to size batteries, solar, and wiring. |
| calculate_solar_size | Size a solar array from daily energy needs, sun hours, and system voltage. |
| list_component_types | Enumerate the component categories VoltPlan understands before another tool call. |
What you can ask once it is connected
With the MCP connected, your assistant calls the tools automatically. Try prompts like these:
Prefer to do it yourself?
Wiring Diagram Maker
The same engine as a free in-browser drag-and-drop diagram tool — no install.
Open the maker →API & agent docs
HTTP API, llms.txt corpora, and the full machine-readable index for agents.
Read the docs →Wire Gauge Calculator
Quick one-cable AWG / mm², voltage drop, and fuse sizing in the browser.
Size a cable →Frequently Asked Questions
What is the Wiring Diagram MCP?
It is a Model Context Protocol (MCP) server published by VoltPlan. Once connected to an MCP-compatible client like Claude Desktop, Claude Code, or Cursor, it gives your AI assistant a set of tools to generate 12V/24V/48V wiring diagrams and to size wires, fuses, battery banks, solar arrays, inverters, and charging times for campers, boats, vans, and off-grid systems. The assistant calls these tools on your behalf during a normal chat.
How do I connect to the Wiring Diagram MCP?
Use the hosted server — there is nothing to install. Add the URL https://mcp.voltplan.app/mcp to your client. In Claude Code run "claude mcp add wiring-diagram --transport http https://mcp.voltplan.app/mcp". In Claude Desktop or Cursor add a "wiring-diagram" entry with that url to the mcpServers block of your config, then restart the client. No API key or account is required.
Do I need to install or run anything?
No. The server is hosted at https://mcp.voltplan.app/mcp, so you only paste a URL into your client — no npx, no Node.js, nothing running on your machine. If you would rather run it locally or self-host, the GitHub repo has npx and self-hosted instructions, but the hosted endpoint is the recommended path.
Which MCP clients are supported?
Any client that supports a remote MCP server over HTTP: Claude Desktop, Claude Code, Cursor, Cline, Windsurf, and others. You add the same URL in each; only the config file location differs.
Is the Wiring Diagram MCP free?
Yes. The hosted server is free to use, the project is open source under the MIT license, and the underlying VoltPlan diagram and sizing engine is free. There is no API key and no account.
What can the AI assistant actually do with it?
Nine tools cover the full design loop: generate a wiring diagram (PNG/SVG), calculate wire gauge and fuse size, size a battery bank, work out a series/parallel battery configuration, estimate charging time, recommend an inverter size, build a 24h power budget, size a solar array, and list known component types. You describe a system in plain language and the assistant calls the right tools to size and draw it.
How is this different from a generic diagram MCP?
Generic diagramming tools draw boxes and arrows with no electrical knowledge. The VoltPlan MCP understands voltage, current, and DC sizing rules, so it picks the correct wire gauge and fuse for every connection (3% voltage-drop rule, 125% fuse rule, NEC/ABYC-aligned ampacities) and flags wiring that would damage equipment. It is purpose-built for low-voltage DC system design, not general flowcharts.
Does it work for AC house wiring?
No. It is scoped to low-voltage DC systems (12V/24V/48V) in campers, RVs, vans, boats, and off-grid cabins, including the AC side where shore power feeds a charger or inverter. It is not built for residential or commercial AC wiring, breaker-panel layout, three-phase, or PCB-level schematics.
Add it to your client now
Paste one URL and your assistant can draw and size complete DC electrical systems. Hosted, free, and open source.
https://mcp.voltplan.app/mcp