LAN MCP CUPS

An MCP server for printing to CUPS network printers via streamable HTTP. Discover printers on a network print server, add them to your local system, and send print jobs directly from Claude Code or other MCP clients.

Transport Modes

• HTTP (default): Runs as an HTTP server at http://127.0.0.1:3000/mcp
• Stdio (legacy): For clients that spawn the process directly

Use Cases

1. Printer Discovery & Setup

"I just set up my laptop on the network. There's a print server somewhere - help me find the printers and add them."

2. Print from Context

"There's a PDF in this repo - print it on the laser printer."

Installation

Using npx (Recommended)

The easiest way to use LAN MCP CUPS is via npx, which runs the package directly without global installation:

npx lan-mcp-cups

With a CUPS server configured:

MCP_CUPS_SERVER=print-server.local npx lan-mcp-cups

Using npm

For a permanent global installation:

npm install -g lan-mcp-cups

Then run:

lan-mcp-cups

Or with environment variable:

MCP_CUPS_SERVER=print-server.local lan-mcp-cups

Claude Code Configuration

Streamable HTTP (Recommended)

Start the server first:

MCP_CUPS_SERVER=print-server.local npx lan-mcp-cups

Then add to your Claude Code settings (~/.claude/settings.json):

{
  "mcpServers": {
    "cups": {
      "url": "http://127.0.0.1:3000/mcp"
    }
  }
}

Stdio Mode (Legacy)

For clients that don't support HTTP transport:

{
  "mcpServers": {
    "cups": {
      "command": "npx",
      "args": ["lan-mcp-cups"],
      "env": {
        "MCP_CUPS_SERVER": "print-server.local",
        "MCP_CUPS_TRANSPORT": "stdio"
      }
    }
  }
}

Replace print-server.local with your CUPS server hostname or IP address.

Environment Variables

CUPS Configuration

| Variable | Default | Description | |----------|---------|-------------| | MCP_CUPS_SERVER | (none) | CUPS server hostname or IP (required for network printing) | | MCP_CUPS_PORT | 631 | CUPS server port | | MCP_CUPS_DEFAULT_PRINTER | (none) | Default printer name | | MCP_CUPS_MAX_COPIES | 10 | Maximum copies per job (0 = unlimited) |

Transport Configuration

| Variable | Default | Description | |----------|---------|-------------| | MCP_CUPS_TRANSPORT | http | Transport mode: http or stdio | | MCP_CUPS_HTTP_HOST | 127.0.0.1 | HTTP server bind address | | MCP_CUPS_HTTP_PORT | 3000 | HTTP server port |

Tools

list_printers

List all printers available on the CUPS server.

User: What printers are available?
AI: [calls list_printers]

Printers on print-server.local:

printer HP_LaserJet is idle.
printer Brother_Color is idle.
system default destination: HP_LaserJet

print_file

Print a local file to a printer on the CUPS server.

Parameters:

• file_path (required) - Path to the file to print
• printer (optional) - Printer name
• copies (optional) - Number of copies
• options (optional) - CUPS options like landscape, sides=two-sided-long-edge

User: Print the README.pdf on the laser printer
AI: [calls print_file with file_path="README.pdf", printer="HP_LaserJet"]

✓ Sent to HP_LaserJet
  File: README.pdf

add_printer

Add a network printer from the CUPS server to your local system. Makes it available for regular printing from any application.

Parameters:

• printer_name (required) - Name of the printer on the remote server
• local_name (optional) - Local name for the printer
• set_default (optional) - Set as system default

User: Add the Brother printer and make it my default
AI: [calls add_printer with printer_name="Brother_Color", set_default=true]

✓ Added printer "Brother_Color"
  URI: ipp://print-server.local/printers/Brother_Color
  Set as default printer

Common CUPS Options

Pass these in the options parameter:

• landscape - Landscape orientation
• sides=two-sided-long-edge - Duplex (long edge binding)
• sides=two-sided-short-edge - Duplex (short edge binding)
• media=A4 or media=Letter - Paper size
• page-ranges=1-5 - Print specific pages
• fit-to-page - Scale to fit
• number-up=2 - Multiple pages per sheet

Requirements

• Linux or macOS with CUPS installed
• Network access to a CUPS print server
• Node.js 18+

Troubleshooting

"No printers found"

• Check MCP_CUPS_SERVER is set correctly
• Verify the server is reachable: lpstat -h print-server.local -p

"Permission denied" when adding printers

• Add your user to the lpadmin group: sudo usermod -aG lpadmin $USER
• Log out and back in for group changes to take effect

Printer not accepting jobs

• Check printer status on the server
• The printer may be paused or have errors

License

MIT

Author

Daniel Rosehill