Installation & Setup

Setting up Hermes MCP for your Elixir project involves a few straightforward steps.

Adding the Dependency

Add Hermes MCP to your dependencies in mix.exs:

def deps do
  [
    {:hermes_mcp, "~> 0.2.0"}
  ]
end

Then run:

mix deps.get

Supervision Tree Integration

Hermes MCP is designed to be integrated into your application's supervision tree. This provides robust lifecycle management and automatic recovery in case of failures.

Basic Integration Example

defmodule MyApp.Application do
  use Application

  def start(_type, _args) do
    children = [
      # Start the MCP transport
      {Hermes.Transport.STDIO, [
        name: MyApp.MCPTransport,
        client: MyApp.MCPClient, 
        command: "mcp",
        args: ["run", "path/to/server.py"]
      ]},
      
      # Start the MCP client using the transport
      {Hermes.Client, [
        name: MyApp.MCPClient,
        transport: MyApp.MCPTransport,
        client_info: %{
          "name" => "MyApp",
          "version" => "1.0.0"
        },
        capabilities: %{
          "resources" => %{},
          "tools" => %{},
          "prompts" => %{}
        }
      ]}
      
      # Your other application services
      # ...
    ]
    
    opts = [strategy: :one_for_one, name: MyApp.Supervisor]
    Supervisor.start_link(children, opts)
  end
end

Configuration Options

Client Configuration

The Hermes.Client accepts the following options:

Transport Configuration

The Hermes.Transport.STDIO accepts the following options:

Environment Requirements

• Elixir 1.18 or later
• Erlang/OTP 26 or later