# SkyWalking NodeJS Agent

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**SkyWalking-NodeJS**: The NodeJS Agent for Apache SkyWalking, which provides the native tracing abilities for NodeJS project.

**SkyWalking**: an APM(application performance monitor) system, especially designed for
microservices, cloud native and container-based (Docker, Kubernetes, Mesos) architectures.

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## Set up NodeJS Agent

SkyWalking NodeJS SDK requires SkyWalking 8.0+.

```typescript
import Agent from 'skywalking';

Agent.start({
  serviceName: '',
  serviceInstance: '',
  collectorAddress: '',
  authorization: '',
  maxBufferSize: 1000,
});
```

The supported environment variables are as follows:

Environment Variable | Description | Default
| :--- | :--- | :--- |
| `SW_AGENT_NAME` | The name of the service | `your-nodejs-service` |
| `SW_AGENT_INSTANCE` | The name of the service instance | Randomly generated |
| `SW_AGENT_COLLECTOR_BACKEND_SERVICES` | The backend OAP server address | `127.0.0.1:11800` |
| `SW_AGENT_AUTHENTICATION` | The authentication token to verify that the agent is trusted by the backend OAP, as for how to configure the backend, refer to [the yaml](https://github.com/apache/skywalking/blob/4f0f39ffccdc9b41049903cc540b8904f7c9728e/oap-server/server-bootstrap/src/main/resources/application.yml#L155-L158). | not set |
| `SW_AGENT_LOGGING_LEVEL` | The logging level, could be one of `CRITICAL`, `FATAL`, `ERROR`, `WARN`(`WARNING`), `INFO`, `DEBUG` | `INFO` |
| `SW_AGENT_MAX_BUFFER_SIZE` | The maximum buffer size before sending the segment data to backend | `'1000'` |

## Supported Libraries

There're some built-in plugins that support automatic instrumentation of NodeJS libraries, the complete lists are as follows:

Library | Plugin Name
| :--- | :--- |
| built-in `http` module | `sw_http` |

## License
Apache 2.0