jlc-mcp

MCP server for JLC/LCSC component sourcing and KiCad library conversion.

Search JLCPCB's parts database, fetch components as KiCad-compatible symbols and footprints, and manage organized component libraries - all through the Model Context Protocol.

Why LCSC?

LCSC is JLC PCB's preferred supplier for assembly (PCBA). Components with LCSC part numbers (e.g., C2040) are guaranteed to be available when ordering PCB assembly from JLCPCB.

• Basic Parts Library: Components marked as "Basic" have no extended part fee ($3 savings per unique part)
• In-Stock Filtering: Search only parts currently available for immediate assembly
• Direct Integration: Fetched components are ready for JLC assembly without manual library work

Features

• Search JLCPCB parts database with stock levels and pricing
• Fetch components directly to KiCad-compatible symbol/footprint format
• Category-based library organization (Resistors, Capacitors, ICs, etc.)
• Hybrid footprint strategy: standard packages use KiCad built-ins, custom packages are generated
• EasyEDA community library support for modules and breakouts
• 3D model downloads (STEP/OBJ formats)

Usage

Option 1: Quick Start (npx)

No installation required - run directly:

npx -y jlc-mcp@latest

Claude Desktop configuration (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "jlc": {
      "command": "npx",
      "args": ["-y", "jlc-mcp@latest"]
    }
  }
}

Option 2: Local Development

Clone and build:

git clone https://github.com/anthropics/ai-eda.git
cd ai-eda/packages/jlc-mcp
bun install
bun run build

Claude Desktop configuration:

{
  "mcpServers": {
    "jlc": {
      "command": "node",
      "args": ["/absolute/path/to/jlc-mcp/dist/index.js"]
    }
  }
}

Note: Restart Claude Desktop after modifying the configuration.

Tools Reference

Search & Discovery

| Tool | Description | Key Parameters | |------|-------------|----------------| | component_search | Search JLCPCB parts or EasyEDA community | query, source, in_stock, basic_only, limit |

Library Management

| Tool | Description | Key Parameters | |------|-------------|----------------| | library_install | Install component to KiCad library | id, project_path?, include_3d?, force? | | library_batch_install | Install up to 10 components at once | ids, include_3d?, force? | | library_get_component | Get installed component metadata | id (LCSC ID) | | library_update | Regenerate all components with latest data | project_path?, dry_run? | | library_fix | Apply pin corrections to a component | id, corrections |

Usage Examples

Search for components

component_search(query="STM32F103", in_stock=true, basic_only=true)

Returns matching components with LCSC IDs, stock levels, and pricing.

Install a component

library_install(id="C8734")

Downloads the component and returns:

• symbol_ref: Reference for schematic (e.g., JLC-MCP-ICs:STM32F103C8T6)
• footprint_ref: Reference for PCB (e.g., Package_QFP:LQFP-48_7x7mm_P0.5mm)

Install to project-local library

library_install(id="C8734", project_path="/path/to/kicad/project", include_3d=true)

Batch install components

library_batch_install(ids=["C2040", "C5446", "C14663"])

Install multiple components in parallel (up to 10 at once).

Regenerate libraries

library_update()

Creates the category-based library structure if it doesn't exist:

• Creates JLC-MCP-Resistors.kicad_sym, JLC-MCP-Capacitors.kicad_sym, etc.
• Creates JLC-MCP.pretty/ footprint directory
• Creates JLC-MCP.3dshapes/ 3D model directory

Library Organization

Category-Based Routing

Components are automatically sorted into category-specific libraries:

| Library | Components | |---------|------------| | JLC-MCP-Resistors.kicad_sym | Resistors, potentiometers | | JLC-MCP-Capacitors.kicad_sym | Capacitors (ceramic, electrolytic, etc.) | | JLC-MCP-Inductors.kicad_sym | Inductors, ferrite beads | | JLC-MCP-Diodes.kicad_sym | Diodes, LEDs, Zeners | | JLC-MCP-Transistors.kicad_sym | MOSFETs, BJTs | | JLC-MCP-ICs.kicad_sym | Integrated circuits, MCUs | | JLC-MCP-Connectors.kicad_sym | Connectors, headers | | JLC-MCP-Misc.kicad_sym | Everything else |

Storage Paths

Global (default):

Libraries are stored in the KiCad 3rdparty folder for cross-platform portability:

• macOS/Windows: ~/Documents/KiCad/9.0/3rdparty/jlc_mcp/
• Linux: ~/.local/share/kicad/9.0/3rdparty/jlc_mcp/

Table entries use ${KICAD9_3RD_PARTY} for portable paths.

~/Documents/KiCad/9.0/3rdparty/jlc_mcp/
├── symbols/
│   ├── JLC-MCP-Resistors.kicad_sym
│   ├── JLC-MCP-Capacitors.kicad_sym
│   └── ...
├── footprints/
│   └── JLC-MCP.pretty/
└── 3dmodels/
    └── JLC-MCP.3dshapes/

Project-local (when project_path specified):

<project>/libraries/
├── symbols/
│   └── JLC-MCP-*.kicad_sym
├── footprints/
│   └── JLC-MCP.pretty/
└── 3dmodels/
    └── JLC-MCP.3dshapes/

Hybrid Footprint Strategy

• Standard packages (0603, 0805, SOIC-8, SOT-23, etc.) use KiCad's built-in footprints
• Non-standard packages get custom footprints generated in JLC-MCP.pretty/

This keeps libraries small while ensuring compatibility.

Integration with ai-eda

When used with the ai-eda toolkit, the /eda-source command provides an interactive component sourcing workflow:

1. Reads project constraints from design-constraints.json
2. Searches local KiCad libraries first, then LCSC online
3. Downloads and analyzes component datasheets
4. Presents options with thermal and assembly validation
5. Fetches selected components with proper references

Example:

/eda-source main-mcu

The command guides you through selecting an MCU that fits your project's requirements, validates it against design constraints, and adds it to your libraries.

Development

bun run dev        # Development with watch mode
bun run build      # Build to ./dist
bun run start      # Run the server
bun run typecheck  # Type checking
bun run test       # Run tests
bun run clean      # Remove dist/

How It Works

1. Search: Queries JLCPCB's API for component data
2. Fetch: Retrieves symbol/footprint data from EasyEDA (LCSC's component library backend)
3. Convert: Transforms EasyEDA format to KiCad S-expression format
4. Route: Categorizes components and routes to appropriate library files
5. Store: Writes KiCad-compatible files and updates library tables

License

MIT