SPICEBridge

AI-powered circuit design through simulation — an MCP server that gives language models direct access to SPICE circuit simulation via ngspice. Describe a circuit in plain English and let the AI handle netlist generation, simulation, measurement, and spec verification.

Features

28 tools covering the full circuit design workflow
11 built-in templates with automatic component value calculation (E24 series)
Simulation: AC sweep, transient, DC operating point
Measurement: bandwidth, gain, DC levels, transient metrics, power
Monte Carlo & worst-case analysis under component tolerances
Multi-stage composition — connect circuit stages with automatic port mapping
Model wizard — generate SPICE .lib models from datasheet parameters
KiCad export — output .kicad_sch schematics
Web viewer — interactive schematic viewer in the browser
Cloud setup wizard — one-command deployment with Cloudflare tunnels (spicebridge setup-cloud)
Spec verification — compare results against design targets

Install

pip install spicebridge

Requirements

Python 3.10+
ngspice installed and on PATH

Quick Start

Local (Claude Code / stdio)

Add to your .mcp.json:

{
  "mcpServers": {
    "spicebridge": {
      "command": "spicebridge"
    }
  }
}

Cloud (Streamable HTTP)

spicebridge --transport streamable-http --port 8000

Cloud Setup Wizard

One command to go from a local install to a public MCP endpoint:

spicebridge setup-cloud          # interactive (named tunnel, permanent URL)
spicebridge setup-cloud --quick  # quick tunnel (temporary URL, no account needed)

The wizard handles the full deployment pipeline:

Installs cloudflared automatically (macOS via Homebrew, Linux via APT) if not found
Authenticates with Cloudflare (browser-based OAuth, named tunnel mode only)
Creates or reuses a tunnel — prompts to pick an existing one or make a new one
Configures DNS routing for your custom domain (named tunnel mode)
Generates an API key for authentication
Starts the SPICEBridge server and tunnel together
Prints connection info with a ready-to-paste JSON config for Claude.ai

Quick tunnels give you a temporary trycloudflare.com URL instantly — no Cloudflare account required. Named tunnels give you a permanent custom domain (e.g. spicebridge.example.com).

Additional options:

spicebridge setup-cloud --domain mcp.example.com  # specify custom domain
spicebridge setup-cloud --port 9000                # custom port
spicebridge setup-cloud --no-install               # skip cloudflared installation

Example

1. load_template("rc_lowpass_1st", specs={"f_3dB_hz": 1000})
   -> netlist with R=1.6k, C=100nF, circuit_id: "a1b2c3d4"

2. run_ac_analysis(circuit_id, start_freq=1, stop_freq=1e6)
   -> frequency response data

3. measure_bandwidth(circuit_id)
   -> f_3dB_hz: 995

4. compare_specs(circuit_id, specs={"f_3dB_hz": {"target": 1000, "tolerance_pct": 5}})
   -> PASS

5. draw_schematic(circuit_id)
   -> schematic SVG

Tools

Create & Configure

Tool	Description
`create_circuit`	Store a SPICE netlist, returns a circuit ID
`delete_circuit`	Delete a stored circuit and clean up resources
`list_templates`	List available circuit templates
`load_template`	Load a template with parameter substitution
`calculate_components`	Calculate component values from target specs
`modify_component`	Change a component value in a stored circuit
`validate_netlist`	Check a netlist for errors before simulation

Simulate

Tool	Description
`run_ac_analysis`	AC frequency sweep
`run_transient`	Transient (time-domain) analysis
`run_dc_op`	DC operating point analysis

Measure

Tool	Description
`measure_bandwidth`	Find -3 dB bandwidth from AC results
`measure_gain`	Measure gain at a specific frequency
`measure_dc`	Extract DC operating point values
`measure_transient`	Measure time-domain characteristics
`measure_power`	Calculate power dissipation

Evaluate & Export

Tool	Description
`get_results`	Retrieve last simulation results
`compare_specs`	Check measurements against target specs
`draw_schematic`	Generate a schematic diagram (PNG/SVG)
`export_kicad`	Export as KiCad 8 schematic (.kicad_sch)
`open_viewer`	Start the interactive web schematic viewer

Composition & Ports

Tool	Description
`set_ports`	Define port-to-node mappings for a circuit
`get_ports`	Return port definitions (auto-detect if unset)
`connect_stages`	Compose multiple stages into a single circuit

Advanced Analysis

Tool	Description
`run_monte_carlo`	Monte Carlo analysis under component tolerances
`run_worst_case`	Worst-case analysis at tolerance extremes
`auto_design`	Full design loop in one call: template + simulate + verify

Model Management

Tool	Description
`create_model`	Generate a SPICE .lib model from datasheet parameters
`list_models`	List all saved models in the model library

Development

git clone https://github.com/clanker-lover/spicebridge.git
cd spicebridge
pip install -e ".[dev]"
pytest

License

GPL-3.0-or-later