conn3x mcp

conn3x mcp starts a Model Context Protocol server on standard input and output. An assistant that speaks MCP can use it to look up Conn3x’s modules and official circuits, check a circuit with validate and lint, and say what a saved plan would change on each host.

Nothing it does applies anything, writes state, or connects to a host. It never runs a plan.

This command is Conn3x only, and new in v0.10.0. It’s experimental: its tools and their output may change between releases.

Usage

conn3x mcp

You don’t run it by hand. Add it to your assistant’s MCP servers as the command conn3x with the argument mcp. Most clients take a JSON entry like this one:

{
  "mcpServers": {
    "conn3x": {
      "command": "conn3x",
      "args": ["mcp"]
    }
  }
}

The server runs in the directory the client starts it in, so validate, lint and summarise_plan read paths relative to that. It speaks MCP revisions 2025-06-18, 2025-03-26 and 2024-11-05.

Tools

Tool	Arguments	What it returns
search_modules	query	Modules a step can use, by name or words in their description. An empty query lists them all.
module_docs	module (required)	One module’s arguments: name, type, whether it’s required, and what it does. The same text as its page in these docs, for this version of Conn3x.
search_circuits	query	Official circuits, by name or words in their description, category or tags, with each one’s repository, latest version, grade and whether it passes. Reads https://conn3x.org/circuits.json.
validate	dir	conn3x validate on a directory: whether the configuration is valid, with each error and warning.
lint	dir	conn3x lint on a directory.
summarise_plan	plan_file (required), dir	For a plan saved with conn3x plan -out=FILE: which steps it would create, change, replace or remove on each host, and the cloud resources apart.

dir defaults to the current directory. For summarise_plan, it defaults to the plan file’s directory.

What stays out

summarise_plan leaves out every attribute value, so a secret in the plan doesn’t reach the assistant. It reads the plan file and nothing else.

search_circuits is the only tool that uses the network, and only to fetch the public circuit catalogue.