# ASYNC_OPTIONS_METADATA_KEYS

**Kind:** Constant

**Source:** [`packages/common/module-utils/constants.ts`](https://github.com/nestjs/nest/blob/master/packages/common/module-utils/constants.ts#L11)

**Part of:** [Common](subsystem-packages-common)

List of keys that are specific to ConfigurableModuleAsyncOptions
and should be excluded when extracting user-defined extras.

`ASYNC_OPTIONS_METADATA_KEYS` defines the option property names reserved by `ConfigurableModuleAsyncOptions`. These keys are excluded when the module utilities extract user-defined “extras,” ensuring framework configuration fields such as factories and imports are not treated as custom module options.

## Definition

```ts
[
  'useFactory',
  'useClass',
  'useExisting',
  'inject',
  'imports',
  'provideInjectionTokensFrom',
] as const
```

## Value

```ts
[
  'useFactory',
  'useClass',
  'useExisting',
  'inject',
  'imports',
  'provideInjectionTokensFrom',
] as const
```

## Diagram

```mermaid
graph LR
  A[ConfigurableModuleAsyncOptions] --> B[Read option keys]
  B --> C{Key in ASYNC_OPTIONS_METADATA_KEYS?}
  C -->|Yes| D[Keep as framework async metadata]
  C -->|No| E[Extract as user-defined extras]
```

## Usage

```ts
import { ASYNC_OPTIONS_METADATA_KEYS } from './constants';

const asyncOptions = {
  imports: [ConfigModule],
  inject: [ConfigService],
  useFactory: (configService: ConfigService) => ({
    apiUrl: configService.get('API_URL'),
  }),
  isGlobal: true,
  retryAttempts: 3,
};

const extras = Object.fromEntries(
  Object.entries(asyncOptions).filter(
    ([key]) => !ASYNC_OPTIONS_METADATA_KEYS.includes(key),
  ),
);

// { isGlobal: true, retryAttempts: 3 }
console.log(extras);
```

## AI Coding Instructions

- Treat this constant as the source of truth for async module option keys owned by the framework.
- Add new keys here when extending `ConfigurableModuleAsyncOptions` with metadata that must not become user-defined extras.
- Do not include keys intended to be forwarded to the generated module’s custom options.
- Preserve the key names exactly as they appear in the async options interface and extraction logic.
- Update related option-extraction tests whenever this list changes.