# `Sagents.MiddlewareEntry`

Represents a registered middleware instance with its configuration.

Each middleware entry contains:
- `id`: Unique identifier (module name by default, or custom string)
- `module`: The middleware module implementing the Middleware behavior
- `config`: Configuration map returned from middleware's init/1 callback

## ID Determination

The middleware ID is used for message routing and uniquely identifies
each middleware instance:

- **Default**: Module name (e.g., `LangChain.Middleware.TodoList`)
- **Custom**: Specified via `:id` option for multiple instances of the same middleware

## Examples

    # Single instance with default ID (module name)
    %MiddlewareEntry{
      id: LangChain.Middleware.TodoList,
      module: LangChain.Middleware.TodoList,
      config: %{middleware_id: LangChain.Middleware.TodoList}
    }

    # Multiple instances with custom IDs
    %MiddlewareEntry{
      id: "title_generator_en",
      module: LangChain.Middleware.ConversationTitle,
      config: %{middleware_id: "title_generator_en", language: "en"}
    }

# `t`

```elixir
@type t() :: %Sagents.MiddlewareEntry{
  config: map(),
  id: atom() | String.t(),
  module: module()
}
```

# `to_raw_spec`

```elixir
@spec to_raw_spec(t() | module() | {module(), keyword()}) ::
  module() | {module(), keyword()}
```

Convert a MiddlewareEntry struct back to raw middleware specification.

This is useful when middleware needs to be re-initialized in a new context,
such as when creating a SubAgent that inherits parent middleware.

## Parameters

- `entry` - A MiddlewareEntry struct or raw middleware spec

## Returns

- Module atom if the middleware has no configuration options
- `{module, opts}` tuple if the middleware has configuration options
- Passes through non-MiddlewareEntry values unchanged

## Examples

    # Entry with no configuration
    entry = %MiddlewareEntry{
      module: MyMiddleware,
      config: %{id: MyMiddleware}
    }
    to_raw_spec(entry)
    # => MyMiddleware

    # Entry with configuration
    entry = %MiddlewareEntry{
      module: MyMiddleware,
      config: %{id: MyMiddleware, max_items: 100, enabled: true}
    }
    to_raw_spec(entry)
    # => {MyMiddleware, [max_items: 100, enabled: true]}

    # Pass through raw specs unchanged
    to_raw_spec(MyMiddleware)
    # => MyMiddleware

    to_raw_spec({MyMiddleware, [opt: "value"]})
    # => {MyMiddleware, [opt: "value"]}

# `to_raw_specs`

```elixir
@spec to_raw_specs([t() | module() | {module(), keyword()}]) :: [
  module() | {module(), keyword()}
]
```

Convert a list of MiddlewareEntry structs to raw middleware specifications.

Convenience function for converting entire middleware lists.

## Parameters

- `entries` - List of MiddlewareEntry structs and/or raw middleware specs

## Returns

- List of raw middleware specifications (module atoms or {module, opts} tuples)

## Examples

    entries = [
      %MiddlewareEntry{module: Middleware1, config: %{id: Middleware1}},
      %MiddlewareEntry{module: Middleware2, config: %{id: Middleware2, opt: "value"}},
      Middleware3
    ]
    to_raw_specs(entries)
    # => [Middleware1, {Middleware2, [opt: "value"]}, Middleware3]

---

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