# ClientProperties

**Kind:** Interface

**Source:** [`packages/microservices/listener-metadata-explorer.ts`](https://github.com/nestjs/nest/blob/master/packages/microservices/listener-metadata-explorer.ts#L16)

**Part of:** [Microservices](subsystem-packages-microservices)

`ClientProperties` describes a discovered microservice client configuration within listener metadata. It pairs the property name used to access the client on a class or instance with the corresponding NestJS `ClientOptions` configuration used to create or identify that client.

## Properties

| Property | Type |
|---|---|
| `property` | `string` |
| `metadata` | `ClientOptions` |

## Diagram

```mermaid
graph LR
  A[Listener Metadata Explorer] --> B[ClientProperties]
  B --> C[property: string]
  B --> D[metadata: ClientOptions]
  C --> E[Client property on provider]
  D --> F[Microservice transport configuration]
```

## Usage

```ts
import type { ClientOptions } from '@nestjs/microservices';

interface ClientProperties {
  property: string;
  metadata: ClientOptions;
}

const clientProperties: ClientProperties = {
  property: 'paymentsClient',
  metadata: {
    transport: 0, // Transport.TCP
    options: {
      host: 'localhost',
      port: 3001,
    },
  },
};

// Example: use the property name to locate the configured client.
console.log(`Discovered client property: ${clientProperties.property}`);
console.log(clientProperties.metadata);
```

## AI Coding Instructions

- Use `property` as the exact property key declared for the microservice client on the provider or controller.
- Provide valid NestJS `ClientOptions` values in `metadata`, including an appropriate `transport` and transport-specific options.
- Preserve both fields when transforming listener metadata; the property name and client configuration must remain associated.
- Avoid treating `property` as a client instance—it is a string identifier used to locate or describe the client.
- Integrate this interface with metadata exploration logic that discovers `@Client()`-configured microservice clients.

## Relationships

- IMPORTS → `Controller`
- IMPORTS → `isFunction`
- IMPORTS → `isUndefined`
- IMPORTS → `MetadataScanner`