netscli-mcp

Model Context Protocol (MCP) server exposing netscli-core tools to LLM agents over JSON-RPC on stdio.

Most users want the netscli binary crate and run netscli serve. This crate is the library it wraps, for embedding the same MCP surface inside a different host process.

Exposed tools

discover_network — live hosts on a subnet.
scan_ports — TCP port scan on a host.
ping_host — ping with packet-loss and RTT statistics.
dns_lookup — forward DNS, all record types. Reverse lookups are not exposed over MCP.
get_arp_table — ARP/neighbour table with vendor resolution.
inspect_host — comprehensive host inspection (ping + scan + DNS).
sweep_network — discovery + port scan in one call.
list_network_interfaces — interfaces with addresses and MAC.
discover_mdns — mDNS/DNS-SD (Bonjour) device discovery (requires the mdns feature, enabled by default).

With the pcap feature (requires libpcap/Npcap at runtime):

capture_pcap — network packet capture to a .pcap file in one blocking tool call.
start_pcap_capture — start a capture as a background job for longer captures.
get_pcap_capture_status — poll a capture job's running/completed/ failed status.
get_pcap_capture_result — fetch a completed capture job's result.

All tool calls return structured JSON so agents don't have to scrape human-oriented output.

Using it standalone

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    netscli_mcp::run_server().await
}

This runs a JSON-RPC MCP server on stdin/stdout. Point your MCP client (Claude Code, Cursor, etc.) at the resulting binary.

MCP client config

For Claude Desktop / Code, with the netscli binary installed:

{
  "mcpServers": {
    "netscli": {
      "command": "netscli",
      "args": ["serve"]
    }
  }
}

Which hosts it will scan

By default this server only scans the local networks: RFC1918 ranges, loopback, link-local, and the carrier-grade NAT range that overlay networks like Tailscale use. A request aimed anywhere else is refused.

The reason is that this surface is driven by a model rather than by the person at the keyboard, and a model may be reading a web page, an issue comment, or a file someone else wrote. The size limits bound how much can be scanned in one call; they say nothing about whose network it is, and the packets leave from your machine and your IP.

To scan public hosts — your own servers, for instance — start the server with the opt-in:

{
  "mcpServers": {
    "netscli": {
      "command": "netscli",
      "args": ["serve"],
      "env": { "NETSCLI_MCP_ALLOW_PUBLIC_TARGETS": "1" }
    }
  }
}

This is a policy, not a sandbox. It stops a model being talked into scanning a stranger; it does not constrain whoever starts the server.

License