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:

1. Installs cloudflared automatically (macOS via Homebrew, Linux via APT) if not found
2. Authenticates with Cloudflare (browser-based OAuth, named tunnel mode only)
3. Creates or reuses a tunnel — prompts to pick an existing one or make a new one
4. Configures DNS routing for your custom domain (named tunnel mode)
5. Generates an API key for authentication
6. Starts the SPICEBridge server and tunnel together
7. 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