MCP Servers — Tool Discovery & Execution

# Run as: iex --dot-iex path/to/notebook.exs

# Title: MCP Servers — Tool Discovery & Execution

# ── What is MCP? ──

# The [Model Context Protocol](https://modelcontextprotocol.io) lets LLMs call
# external tools through a standard interface. Skynet can both **connect to**
# MCP servers (as a client) and **expose actions as** an MCP server.

# ── Connected Servers ──

# See which MCP servers are configured and connected:

alias Toolbox.MCP.ConnectionManager

ConnectionManager.list_connections()

# ── Discover Available Tools ──

# Each connected server exposes tools. Let's list them:

alias Toolbox.MCP.ToolRegistry

tools = ToolRegistry.list_all_tools()

tools
|> Enum.group_by(& &1["_server"])
|> Enum.each(fn {server, tool_list} ->
  IO.puts("\n--- #{server} ---")
  for tool <- tool_list do
    IO.puts("  #{tool["name"]}: #{tool["description"] |> String.slice(0..80)}")
  end
end)

:ok

# ── Call an MCP Tool ──

# Use the `MCPCall` action to invoke a tool on a connected server:

alias Toolbox.Actions.MCPCall

# Example: list files using the filesystem MCP server
{:ok, result} =
  MCPCall.run(
    %{
      server: :filesystem,
      tool: "list_directory",
      arguments: %{"path" => "/tmp"}
    },
    %{}
  )

result

# ── Add a Server at Runtime ──

# You can connect to additional MCP servers without restarting:

# Example: connect to a local MCP server
ConnectionManager.add_server(:my_server, %{
  transport: :stdio,
  command: "npx",
  args: ["-y", "@modelcontextprotocol/server-filesystem", "/home"]
})

# ── Skynet as MCP Server ──

# Skynet also exposes its own actions as MCP tools. External agents
# (Claude Code, Cursor, etc.) can connect to Skynet's MCP server.

# The exposed actions are configured in `config/runtime.exs`:

Application.get_env(:toolbox, :mcp_server)

# To connect from Claude Code, add to your `.claude/settings.json`:

# ```json
# {
#   "mcpServers": {
#     "skynet": {
#       "type": "streamable-http",
#       "url": "http://your-server:4288/mcp"
#     }
#   }
# }
# ```