cisco-pt-mcp 0.1.2

MCP server that drives Cisco Packet Tracer through a bridge extension.

cisco-pt-mcp

An MCP server that lets any MCP-aware client (Claude Desktop, Cursor, Backboard, VS Code, ...) drive a running Cisco Packet Tracer instance.

┌───────────────────┐                       ┌──────────────────────┐
│                   │                       │     cisco-pt-mcp     │
│     MCP client    │ ◄──── stdio MCP ────► │   server (Python)    │
│                   │                       │                      │
└───────────────────┘                       └───────────┬──────────┘
                                                        │
                                                        │  Socket.IO 127.0.0.1:7531
                                                        ▼
                                           ┌─────────────────────────┐
                                           │      Packet Tracer +    │
                                           │     cisco-pt-mcp.pts    │
                                           │     bridge extension    │
                                           └─────────────────────────┘

The PT extension shows a small bridge window (Extensions → Packet Tracer MCP) with a connection-status pill and a tool-call activity log — purely diagnostic.

Layout

cisco-pt-mcp/
├─ pyproject.toml                  # console_script: cisco-pt-mcp = mcp_server.server:main
├─ mcp_server/
│  ├─ __main__.py                  # python -m mcp_server entrypoint
│  ├─ server.py                    # MCP stdio server, registers tools, forwards to bridge
│  ├─ bridge.py                    # PTBridge: Socket.IO server on 127.0.0.1:7531
│  └─ tools.py                     # 9 tool schemas (single source of truth)
├─ extension/source/                # packaged into cisco-pt-mcp.pts
│  ├─ main.js                      # PT lifecycle, Extensions menu item
│  ├─ window.js                    # webview controller (this-sm:index.html)
│  ├─ runcode.js                   # $se('runCode') eval host
│  ├─ userfunctions.js             # the 9 tool implementations (PT scripting host)
│  ├─ devices.js / links.js / modules.js   # PT type-id lookup tables
│  └─ interface/                   # webview, browser context
│     ├─ index.html                # status pill + activity log
│     ├─ interface.js              # Socket.IO client, $se dispatcher
│     └─ socket.io.min.js          # vendored client
└─ tests/test_smoke.py             # 6 offline smoke tests

The split between extension/source/*.js (PT scripting host: ipc.network(), webViewManager, $se) and extension/source/interface/* (webview browser context: DOM, socket.io, talks to PT only via $se('runCode', ...)) is load-bearing — see Cisco's own Cisco-Agent extension for the same pattern.

Install

1. Server

The server is published on PyPI. No cloning or venv setup required — uvx handles everything in an isolated environment. Install uv if you don't have it yet (single command on any platform), then register the server with your MCP client:

Client	One-line registration
Claude Code	claude mcp add cisco-pt-mcp --scope user -- uvx cisco-pt-mcp
Claude Desktop	%APPDATA%\Claude\claude_desktop_config.json — JSON below
Cursor	%USERPROFILE%\.cursor\mcp.json (or .cursor/mcp.json per project) — same JSON
VS Code	.vscode/mcp.json — JSON below (note different key name)
Codex CLI	%USERPROFILE%\.codex\config.toml — TOML below
Backboard CLI	backboard config add-mcp '{"name": "cisco-pt-mcp", "command": "uvx", "args": ["cisco-pt-mcp"]}'

Claude Desktop / Cursor (mcpServers):

{
  "mcpServers": {
    "cisco-pt-mcp": { "command": "uvx", "args": ["cisco-pt-mcp"] }
  }
}

VS Code (servers):

{
  "servers": {
    "cisco-pt-mcp": { "command": "uvx", "args": ["cisco-pt-mcp"] }
  }
}

Codex CLI (TOML):

[mcp_servers.cisco-pt-mcp]
command = "uvx"
args = ["cisco-pt-mcp"]

Backboard CLI (one-shot command, persists to ~/.backboard/config.json):

backboard config add-mcp "{\"name\": \"cisco-pt-mcp\", \"command\": \"uvx\", \"args\": [\"cisco-pt-mcp\"]}"

Verify with backboard config list-mcp. Toggle off/on later with backboard config disable-mcp cisco-pt-mcp / enable-mcp cisco-pt-mcp.

Fallback: If uvx isn't available, install the package manually and point directly at the binary:

{ "mcpServers": { "cisco-pt-mcp": { "command": "C:\\path\\to\\.venv\\Scripts\\cisco-pt-mcp.exe" } } }

For remote use, expose this server through mcp-remote; HTTP transport is intentionally not built in.

2. Extension

Install extension/cisco-pt-mcp.pts through Packet Tracer's own extension manager:

1. Open Packet Tracer.
2. Extensions → Extensions Manager → Install Extension…
3. Pick extension/cisco-pt-mcp.pts from this repo.
4. Restart Packet Tracer when prompted.

Extensions → Packet Tracer MCP now shows in the menu — click it to open the bridge window.

Prefer to drop it in by hand? The per-user extensions directory is %USERPROFILE%\Cisco Packet Tracer <version>\extensions\cisco-pt-mcp\.

To rebuild after editing extension/source/*.js, use PT's Extensions → Scripting workflow to re-package the source folder into a new .pts, then reinstall via the Extensions Manager.

Run

1. Launch Packet Tracer; click Extensions → Packet Tracer MCP. The bridge window opens with status connecting then offline.
2. Launch your MCP client. It spawns cisco-pt-mcp.exe as a subprocess; within a second the bridge window flips to connected.
3. Ask the model to do something. Tool calls show up in the bridge window's Activity log.

Tools exposed

Tool	Purpose
addDevice	Drop a router/switch/PC on the canvas
addModule	Install an interface module in a device slot
addLink	Connect two devices with a cable
removeDevice	Delete one or more devices
removeLink	Delete one or more cables
configurePcIp	Set IP / DHCP / gateway / DNS on a PC
configureIosDevice	Run IOS CLI commands on a router/switch
getNetwork	Snapshot of all devices, interfaces, cables
getDeviceInfo	Detail view of a single device

All tool calls return JSON {success, ...}; errors come back as {success: false, error: "..."} so the model can recover.

Configuration

Variable	Default	Meaning
CISCO_PT_MCP_TOOL_TIMEOUT	60	Seconds to wait for a tool result
CISCO_PT_MCP_LOG_LEVEL	INFO	Server log level

The bridge endpoint is hard-coded to 127.0.0.1:7531 (both ends are local). To retarget, edit MCP_URL in extension/source/interface/interface.js and the constants in mcp_server/bridge.py, then rebuild the .pts.

Tests

pip install -e .[dev]
pytest tests\ -v

Offline tests — no Packet Tracer required.

License

MIT