# INestMicroservice

**Kind:** Interface

**Source:** [`packages/common/interfaces/nest-microservice.interface.ts`](https://github.com/nestjs/nest/blob/master/packages/common/interfaces/nest-microservice.interface.ts#L14)

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

Interface describing Microservice Context.

`INestMicroservice` describes the runtime context of a NestJS microservice application. It exposes lifecycle state through an RxJS observable, allowing integrations to react to status changes such as startup, readiness, or shutdown.

## Properties

| Property | Type |
|---|---|
| `status` | `Observable<string>` |

## Diagram

```mermaid
graph LR
  A[Microservice Bootstrap] --> B[INestMicroservice]
  B --> C[status: Observable<string>]
  C --> D[Lifecycle State Subscribers]
  D --> E[Monitoring / Shutdown / Integration Logic]
```

## Usage

```ts
import { INestMicroservice } from '@nestjs/common';

async function monitorMicroservice(app: INestMicroservice) {
  app.status.subscribe((status) => {
    console.log(`Microservice status: ${status}`);
  });

  await app.listen();
}
```

## AI Coding Instructions

- Treat `status` as an RxJS `Observable`; subscribe to it rather than reading it as a synchronous string value.
- Clean up long-lived subscriptions when adding custom lifecycle monitoring to avoid memory leaks.
- Use the interface when accepting a microservice application context in reusable helpers or integration code.
- Keep lifecycle-dependent logic resilient to multiple status emissions, including startup and shutdown transitions.

## Used by

4 references from 4 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

### Imported by (4)

- `NestApplication` — `packages/core/nest-application.ts`:54
- `IEntryNestModule` — `packages/core/nest-factory.ts`:39
- `NestMicroservice` — `packages/microservices/nest-microservice.ts`:35
- `TestingModule` — `packages/testing/testing-module.ts`:26