# `Mead.MCP.Server`
[🔗](https://github.com/albertosca/mead/blob/main/lib/mead/mcp/server.ex#L1)

The server side of MCP: an HTTP listener that lets a client with the configured token drive
sessions as tools (see `Mead.MCP.Server.Tools`). The last child of the root supervisor.

Configured by `config :mead, :mcp_server` (see `Mead.MCP.Server.Configuration`). Without a
`:token` it starts nothing and logs one info line, so a runtime that was never set up for it
opens no port. An invalid setting stops the application at boot with a message that names the
setting and never contains the token.

The listener is a `Bandit` instance running `Mead.Gateway`, which serves `Mead.MCP.Server.Plug`
when `:mcp_server` has a token and `Mead.Deck.Plug` when `:deck` has one (the deck reuses the
`:allowed_origins` of `:mcp_server`), and starts when either does. It is supervised
`:one_for_one`, so a listener that dies is started again without touching the hub or the
sessions. A port that is already taken stops the start, loudly, as any other boot error.

Tests start their own server with `:settings`, `:deck_settings` (replacing the application
environment) and `:deck_options` (extra options for `Mead.Deck.Plug`, such as the session
handler).

# `child_spec`

Returns a specification to start this module under a supervisor.

See `Supervisor`.

# `port`

```elixir
@spec port(Supervisor.supervisor()) :: {:ok, :inet.port_number()} | :error
```

The port the listener is bound to, which is what a test that asked for port 0 needs to know.
`:error` when the server has no listener or is not running.

# `start_link`

```elixir
@spec start_link(keyword()) :: Supervisor.on_start()
```

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*Consult [api-reference.md](api-reference.md) for complete listing*