VoltPlan Wiring Diagrams

Official registry Other

Generate 12V/24V/48V wiring diagrams and size wires, fuses, batteries, solar, and inverters.

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)

Claude Code

claude mcp add --transport http voltplan-wiring-diagrams 'https://mcp.voltplan.app/mcp'

JSON configuration (Claude Desktop, Cursor, VS Code)

{
    "mcpServers": {
        "voltplan-wiring-diagrams": {
            "type": "http",
            "url": "https://mcp.voltplan.app/mcp"
        }
    }
}

NPM package wiring-diagram-mcp

Claude Code

claude mcp add voltplan-wiring-diagrams -e 'VOLTPLAN_API_URL=<VOLTPLAN_API_URL>' -- npx -y wiring-diagram-mcp@0.3.0

JSON configuration (Claude Desktop, Cursor, VS Code)

{
    "mcpServers": {
        "voltplan-wiring-diagrams": {
            "command": "npx",
            "args": [
                "-y",
                "wiring-diagram-mcp@0.3.0"
            ],
            "env": {
                "VOLTPLAN_API_URL": "<VOLTPLAN_API_URL>"
            }
        }
    }
}

Environment variables

VOLTPLAN_API_URL URL of the VoltPlan API instance

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents

VoltPlan Wiring Diagrams · MCP Server
Why this exists
What it does
Demo
5-minute setup
Architecture
Telemetry
Examples
Roadmap
Related
About
License

VoltPlan Wiring Diagrams · MCP Server

I refit my boat with Claude as the electrician. Here's the MCP that made it possible.

An MCP server that gives Claude (or any MCP-compatible AI) domain expertise in 12V / 24V / 48V electrical systems — sizing the bank, picking the wire gauge, recommending the fuse, and generating a complete wiring diagram. For boats, campers, vans, and off-grid builds.

{ "mcpServers": { "wiring-diagram": { "url": "https://mcp.voltplan.app/mcp" } } }

Drop that into your claude_desktop_config.json, restart Claude, ask: "Plan a 400 Ah lithium house bank for a 30 ft sailboat with 2 days of autonomy." Done.

Why this exists

Built while refitting Largo, a 1996 Maxum, in Roermond. The math kept getting in the way of the work — sizing the bank, then the gauge, then the fuse, then redoing all of it after one load changed. So I gave Claude the math. Now it sizes the bank, picks the gauge, and generates the diagram. I'd rather just do the cabling.

The calculations are the same ones any cruiser or vanlifer ends up doing on graph paper at 11pm. This server makes them a one-sentence prompt.

What it does

Nine tools, all callable by name from any MCP client:

Tool	What it does
`calculate_power_budget`	Daily energy draw from a list of loads (Wh, Ah, peak power)
`calculate_battery_bank`	Bank size for given consumption + autonomy + DoD
`calculate_battery_config`	Series/parallel arrangement to hit a target voltage and capacity
`calculate_solar_size`	Panel wattage to recharge daily, accounting for sun hours and losses
`calculate_wire_gauge`	AWG / mm² for current and run length, with fuse recommendation
`calculate_inverter_size`	Inverter wattage for AC loads, with surge headroom and DC current draw
`calculate_charging_time`	Time from X% to Y% SoC, with bulk and absorption phases
`generate_wiring_diagram`	Complete schematic as an image (PNG, default) or icon-free SVG, auto-fused and protected, plus a link that opens the system in the VoltPlan editor
`list_component_types`	Component reference and example configs for diagram building

Demo

Three real prompts, three real outputs.

1. Size a sailboat house bank

"Plan a 400 Ah lithium house bank for a 30 ft sailboat. Loads: 12V fridge 24/7 (60W), LED nav and cabin lights (25W, 4h/day), USB chargers (30W, 2h/day), occasional inverter for a laptop (90W, 3h/day). 2 days of autonomy without solar, LiFePO4 with 80% DoD."

Claude calls calculate_power_budget then calculate_battery_bank:

Total daily energy: 1,870 Wh/day  (155.8 Ah/day at 12V)
Peak load:           205 W        (17.1 A)

Required capacity (2 days × 80% DoD):  4,675 Wh / 389.6 Ah
Recommended bank: 4 × 100 Ah / 12.8 V LiFePO4 in parallel (4P)
Total / usable:   400 Ah / 5,120 Wh   →   4,096 Wh usable
                  ≈ 2.2 days of autonomy

2. Pick a gauge for an inverter run

"What gauge wire for a 50A inverter run, 3 meters one-way, 12V, marine environment, max 3% drop?"

Claude calls calculate_wire_gauge:

Recommended cable:    16 mm² (6 AWG)   — rated 65 A
Voltage drop:         0.34 V (2.80%)   ✓ within target
Total resistance:     6.7 mΩ
Power lost as heat:   16.8 W
Fuse:                 70 A ANL bolt-down, within 18 cm of battery+

Status: OK — wire size meets all requirements.

(Ampacity alone would allow 10 mm² / 8 AWG, but voltage drop drives the choice up at this length.)

3. Generate a full schematic

"Generate a wiring diagram for: 2 × 100W solar → MPPT → 200 Ah LiFePO4 → BMV-712 monitor → main 12V bus → fridge, lights, USB."

Claude calls generate_wiring_diagram and shows the schematic as an image: batteries with terminals, MPPT charger, auto-generated shunt, main switch, low-voltage cutoff, and fused load lines in red/black with computed gauges. Below it comes a link that opens the system in the VoltPlan editor with the battery, the solar panel and the first load already placed, to finish, save and turn into a shopping list.

Loads need only power or current, batteries only capacityAh or energyWh; the server derives the rest, and voltages default to the first battery's.

See examples/ for five fully-worked scenarios — sailboat refit, Sprinter van, off-grid cabin, day sailer, live-aboard — each with the prompt, the expected tool calls, and the resulting numbers.

5-minute setup

Claude Desktop (hosted — easiest)

Edit claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "wiring-diagram": {
      "url": "https://mcp.voltplan.app/mcp"
    }
  }
}

Restart Claude. The hammer icon in the chat input means tools are active.

Claude Desktop (local via npx)

{
  "mcpServers": {
    "wiring-diagram": {
      "command": "npx",
      "args": ["wiring-diagram-mcp"]
    }
  }
}

Claude Code

# hosted
claude mcp add wiring-diagram --transport http https://mcp.voltplan.app/mcp

# local
claude mcp add wiring-diagram -- npx wiring-diagram-mcp

Cursor

Edit ~/.cursor/mcp.json (or .cursor/mcp.json per-project):

{
  "mcpServers": {
    "wiring-diagram": {
      "url": "https://mcp.voltplan.app/mcp"
    }
  }
}

Cline (VS Code)

Open the Cline panel → MCP Servers → Edit MCP Settings, then:

{
  "mcpServers": {
    "wiring-diagram": {
      "url": "https://mcp.voltplan.app/mcp"
    }
  }
}

Self-hosted HTTP server

npm install
npm run build
npm run start:http   # listens on http://localhost:3001/mcp

Env var	Default	Purpose
`VOLTPLAN_API_URL`	`https://voltplan.app`	VoltPlan instance for diagram rendering
`VOLTPLAN_PB_URL`	`https://base.voltplan.app`	VoltPlan catalogue (public, read-only) for curated cable and fuse links
`VOLTPLAN_TELEMETRY`	on	`off` disables the usage events described under Telemetry
`PORT`	`3001`	HTTP server port

Docker

docker build -t wiring-diagram-mcp .
docker run -p 3001:3001 wiring-diagram-mcp

Architecture

Calculations run inside the MCP server and are deterministic. Diagram rendering hits the VoltPlan API and returns a PNG (or SVG) that the AI client shows in the chat. calculate_wire_gauge additionally reads VoltPlan's public catalogue (cached for an hour) to link the recommended cable and fuse to a curated product; without it the links fall back to a store search.

Links and attribution

Buy links go through voltplan.app/api/go with source=mcp, which picks the reader's local Amazon store; VoltPlan earns a commission on purchases (Amazon Associate). Links to voltplan.app pages carry utm_source=mcp.

Telemetry

The server sends anonymous usage events to VoltPlan's cookieless analytics (Umami): connection handshakes and tool calls, with the tool name, a few coarse inputs (system voltage, output format) and the client's product name (e.g. claude-ai, from the MCP clientInfo or the HTTP User-Agent). No prompts, no tool arguments beyond those, no IP-derived identifiers. Set VOLTPLAN_TELEMETRY=off to disable it.

Examples

Worked scenarios in examples/:

Roadmap

AC-side calculations: shore power inlet, breaker panel sizing, isolation transformer
More battery chemistries: AGM/Gel sizing curves, lead-carbon
Multi-bank topologies: starter + house with combiner / DC-DC charger
Wire run optimization: shared trunks, terminal block placement

VoltPlan — web app for visual electrical system design
VoltPlan Wire Gauge Calculator — free, no signup

About

Built by Stefan Lange-Hegermann (yuzuhub.com). Powered by VoltPlan.

Issues, ideas, and pull requests welcome on GitHub.

License

MIT — see LICENSE.

Frequently asked questions

What is VoltPlan Wiring Diagrams?

Generate 12V/24V/48V wiring diagrams and size wires, fuses, batteries, solar, and inverters.

How do I install VoltPlan Wiring Diagrams?

It runs as a remote server. In Claude Code: claude mcp add --transport http voltplan-wiring-diagrams 'https://mcp.voltplan.app/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does VoltPlan Wiring Diagrams need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is VoltPlan Wiring Diagrams open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains VoltPlan Wiring Diagrams?

It is published by YUZU-Hub. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.

Server details

Listed in: Official MCP Registry
Publisher: YUZU-Hub
Category: Other
Runs: Remote + Local
GitHub stars: ★ 0
License: MIT
Language: TypeScript
Last commit: Oct 26, 2026
Open issues: 0
Version: 0.3.0
Published: Oct 26, 2026

io.github.YUZU-Hub/wiring-diagram-mcp

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Other

VoltPlan Wiring Diagrams

Install

Documentation

VoltPlan Wiring Diagrams · MCP Server

Why this exists

What it does

Demo

1. Size a sailboat house bank

2. Pick a gauge for an inverter run

3. Generate a full schematic

5-minute setup

Claude Desktop (hosted — easiest)

Claude Desktop (local via npx)

Claude Code

Cursor

Cline (VS Code)

Self-hosted HTTP server

Docker

Architecture

Links and attribution

Telemetry

Examples

Roadmap

Related

About

License

Frequently asked questions