# `ExAthena.Mcp`
[🔗](https://github.com/udin-io/ex_athena/blob/v0.7.1/lib/ex_athena/mcp.ex#L1)

Facade for MCP (Model Context Protocol) server management.

## Read APIs (high-level — requires Supervisor running)

  * `list_servers/0` — metadata for every registered MCP server. Disabled
    servers are not started and therefore do not appear in this list.
  * `list_tools/1` — cached tools for a server by name.

## Low-level APIs (client-pid based)

  * `list_tools/2` — list tools from a running `Client` pid.
  * `call_tool/4` — invoke a named tool on a running `Client` pid.

# `call_tool`

```elixir
@spec call_tool(pid(), String.t(), map(), non_neg_integer()) ::
  {:ok, map()} | {:error, term()}
```

Call a named tool on a `Client` process directly.

# `list_servers`

```elixir
@spec list_servers() :: [map()]
```

Return metadata for every running MCP server (i.e. every server registered
in the registry). Disabled servers are not started, so they are not included.

Each entry is a map with keys `:name`, `:status`, `:type`, `:enabled`,
`:tool_count`, `:error`.

# `list_tools`

```elixir
@spec list_tools(String.t()) :: {:ok, [map()]} | {:error, :not_found | term()}
```

Return cached tools for the server registered under `name`.

Returns `{:ok, [tool_map]}` or `{:error, :not_found | %ExAthena.Error{}}`.

# `list_tools`

```elixir
@spec list_tools(pid(), non_neg_integer()) :: {:ok, [map()]} | {:error, term()}
```

List tools from a running `Client` process directly.

Lower-level than `list_tools/1` — callers that hold a pid use this.

# `tool_specs`

```elixir
@spec tool_specs(:all | [String.t()]) :: [ExAthena.Tool.Spec.t()]
```

Return `[Tool.Spec.t()]` for all ready, enabled MCP servers.

`filter` controls which servers contribute specs:
  * `:all` — all ready+enabled servers
  * `[server_name]` — only the named servers

When the MCP supervisor is not running, returns `[]` without raising.

---

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