# `ClaudeAgentSDK.Tool.Registry`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L1)

GenServer that manages tool registration and execution for SDK MCP servers.

The Registry maintains a mapping of tool names to their metadata and execution modules,
enabling:
- Tool registration at server startup
- Tool lookup by name
- Tool execution dispatch
- Concurrent access to tool definitions

## Usage

    {:ok, pid} = Registry.start_link([])

    tool = %{
      name: "calculator",
      description: "Calculate",
      input_schema: %{type: "object"},
      module: MyTools.Calculator
    }

    :ok = Registry.register_tool(pid, tool)
    {:ok, result} = Registry.execute_tool(pid, "calculator", %{"expression" => "2+2"})

# `state`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L39)

```elixir
@type state() :: %{tools: %{required(String.t()) => tool_metadata()}}
```

# `tool_metadata`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L32)

```elixir
@type tool_metadata() :: %{
  name: tool_name(),
  description: String.t(),
  input_schema: map(),
  module: module()
}
```

# `tool_name`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L30)

```elixir
@type tool_name() :: String.t() | atom()
```

# `child_spec`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L27)

Returns a specification to start this module under a supervisor.

See `Supervisor`.

# `execute_tool`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L161)

```elixir
@spec execute_tool(GenServer.server(), tool_name(), map()) ::
  {:ok, map()} | {:error, term()}
```

Executes a tool with given input.

## Parameters

- `registry` - Registry PID or name
- `name` - Tool name (atom)
- `input` - Input map matching tool's input_schema

## Returns

- `{:ok, result}` - Tool executed successfully
- `{:error, reason}` - Execution failed

## Examples

    {:ok, result} = Registry.execute_tool(pid, "add", %{"a" => 5, "b" => 3})

# `get_tool`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L116)

```elixir
@spec get_tool(GenServer.server(), tool_name()) ::
  {:ok, tool_metadata()} | {:error, :not_found}
```

Gets a tool by name from the registry.

## Parameters

- `registry` - Registry PID or name
- `name` - Tool name (atom)

## Returns

- `{:ok, tool}` - Tool found
- `{:error, :not_found}` - Tool not found

## Examples

    {:ok, tool} = Registry.get_tool(pid, "calculator")

# `list_tools`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L137)

```elixir
@spec list_tools(GenServer.server()) :: {:ok, [tool_metadata()]}
```

Lists all registered tools.

## Parameters

- `registry` - Registry PID or name

## Returns

`{:ok, tools}` where tools is a list of tool metadata maps.

## Examples

    {:ok, tools} = Registry.list_tools(pid)
    Enum.each(tools, fn tool -> IO.puts(tool.name) end)

# `register_tool`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L93)

```elixir
@spec register_tool(GenServer.server(), tool_metadata()) ::
  :ok | {:error, :already_registered}
```

Registers a tool with the registry.

## Parameters

- `registry` - Registry PID or name
- `tool` - Tool metadata map

## Returns

- `:ok` - Successfully registered
- `{:error, :already_registered}` - Tool already exists

## Examples

    tool = %{
      name: "add",
      description: "Add numbers",
      input_schema: %{type: "object"},
      module: MyTools.Add
    }

    :ok = Registry.register_tool(pid, tool)

# `start_link`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.9.2/lib/claude_agent_sdk/tool/registry.ex#L58)

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

Starts the registry GenServer.

## Options

- `:name` - Optional name for the registry

## Examples

    {:ok, pid} = Registry.start_link([])
    {:ok, pid} = Registry.start_link(name: :my_registry)

---

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