ltspice — Local Claude Code Plugin for LTspice
A local plugin that gives Claude Code full read/build/edit/simulate/visualize
capability over LTspice circuits. Every schematic produced is a standard .asc
file that opens in the LTspice GUI on double-click.
What's inside
ltspice/
.claude-plugin/plugin.json Plugin manifest
.claude-plugin/marketplace.json Lets the repo install via /plugin marketplace
skills/ltspice-circuits/SKILL.md Auto-loaded workflow primer
commands/ /ltspice:inspect, sim, plot, build, open
lib/ltspice_cli.py The CLI Claude calls
lib/mcp_server.py Optional MCP wrapper (Claude Desktop, etc.)
lib/requirements.txt spicelib, numpy, matplotlib
references/ Deep LTspice references the skill links to
tests/ Pytest suite + reference circuits
Install
This is a Claude Code plugin. Pick one of two install methods, then install
the Python dependencies.
Option A — clone into your local plugins folder (simplest)
Claude Code auto-discovers any plugin under ~/.claude/plugins/local/, so a
plain clone is enough:
git clone <REPO-URL> "$env:USERPROFILE\.claude\plugins\local\ltspice"
Restart Claude Code. The /ltspice:* commands and the ltspice-circuits
skill load automatically (it shows up as ltspice@skills-dir in /plugin).
Option B — install as a marketplace plugin (clean enable/disable + updates)
The repo doubles as a Claude Code marketplace, so you can also do:
/plugin marketplace add <github-owner>/<repo>
/plugin install ltspice@ltspice
Install the Python dependencies (required for both options)
cd into the plugin folder and install its requirements:
cd "$env:USERPROFILE\.claude\plugins\local\ltspice" # or wherever it was installed
py -m pip install --user -r lib\requirements.txt
py -m pip install --user pytest # only needed for the test suite
CLI usage
The /ltspice:* slash commands are the normal entry point. To call the CLI
directly (from the plugin folder):
py lib\ltspice_cli.py <subcommand>
Subcommands
Read/debug:
inspect <file.asc> — structured circuit view (components, nets, directives)sim <file.asc> — batch-mode simulation; reports errors or log tailsignals <file.raw> — list traces; surfaces stepped-sweep structureprobe <file.raw> <sig> [--at X] [--values N] — numeric extraction;
handles AC complex traces automatically (reports |mag| @phase, in dB)op <file.asc> — operating-point analysis (replaces other analyses)plot <file.raw> <sig> [sig...] — render PNG (for AC: Bode magnitude in dB)open <file> — launch .asc/.raw in LTspice GUI (Windows file-association)
Edit (byte-safe, preserves geometry and CRLF):
set-value <file.asc> <RefDes> <value> — change one component's Valueset-directive <file.asc> <regex> <new> — replace a SPICE directive
Build from scratch:
new <file.asc> — blank schematic with Version 4.1 headerpins <symbol> — show pin coordinates (relative or with --x/--y/--rotation)add-component <file> <symbol> <x> <y> — auto-numbers RefDes; reports pin coordsadd-wire <file> <x1> <y1> <x2> <y2>add-flag <file> <x> <y> <name> (name=0 for ground)add-directive <file> <body>
Advanced:
meas <file.log> [name] — read .meas directive results from a simulation lognetlist <file.asc> [--out P] — convert a schematic to a SPICE netlist (.net)new-symbol <file.asy> <n_pins> — generate a minimal .asy block symbol for a subcircuit
Test suite
Run the full suite to verify everything works on your machine:
cd "$env:USERPROFILE\.claude\plugins\local\ltspice\tests"
py -m pytest -v
Or double-click tests/run_tests.bat.
126 tests covering: .asc parsing, symbol/pin lookup with rotation,
build-from-scratch, byte-safe edits, simulating seven reference circuits with
numeric claims (voltage divider, RC low-pass AC + transient, diode IV,
2N3904 common emitter, half-wave rectifier, RC step with .meas), and PNG
plot generation.
The seven reference circuits in tests/circuits/ are standalone .asc files
— double-click them to open in LTspice and verify the claims yourself.
See tests/circuits/README.md for the table of expected values.
Per-project setup
In any project directory:
my-project/
CLAUDE.md Tells Claude this is an LTspice project
circuits/ New schematics (double-click → LTspice)
plots/ PNG renders from `ltspice plot`
The plot subcommand auto-targets ./plots/ if it exists.
Requirements
