> ## Documentation Index
> Fetch the complete documentation index at: https://axiom.co/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Axiom transport for Winston logger

> This page explains how to send data from a Node.js app to Axiom through Winston.

## Prerequisites

* [Create an Axiom account](https://app.axiom.co/register).
* [Create a dataset in Axiom](/reference/datasets#create-dataset) where you send your data.
* [Create an API token in Axiom](/reference/tokens) with permissions to ingest data to the dataset you have created.

## Install SDK

To install the SDK, run the following:

```shell theme={null}
npm install @axiomhq/winston
```

## Import the Axiom transport for Winston

```js theme={null}
import { WinstonTransport as AxiomTransport } from '@axiomhq/winston';
```

## Create a Winston logger instance

```js theme={null}
const logger = winston.createLogger({
    level: 'info',
    format: winston.format.json(),
    defaultMeta: { service: 'user-service' },
    transports: [
        // You can pass an option here. If you don’t, the transport is configured automatically
        // using environment variables like `AXIOM_DATASET` and `AXIOM_TOKEN`
        new AxiomTransport({
            dataset: 'DATASET_NAME',
            token: 'API_TOKEN',
        }),
    ],
});
```

<Info>
  Replace `API_TOKEN` with the Axiom API token you have generated. For added security, store the API token in an environment variable.

  Replace `DATASET_NAME` with the name of the Axiom dataset where you send your data.
</Info>

After setting up the Axiom transport for Winston, use the logger as usual:

```js theme={null}
logger.log({
    level: 'info',
    message: 'Logger successfully setup',
});
```

### Error, exception, and rejection handling

To log errors, use the [`winston.format.errors`](https://github.com/winstonjs/logform#errors) formatter. For example:

```ts theme={null}
import winston from 'winston';
import { WinstonTransport as AxiomTransport } from '@axiomhq/winston';
const { combine, errors, stack } = winston.format;
const axiomTransport = new AxiomTransport({ ... });
const logger = winston.createLogger({
  // 8<----snip----
  format: combine(errors({ stack: true }), json()),
  // 8<----snip----
});
```

To automatically log exceptions and rejections, add the Axiom transport to the [`exceptionHandlers`](https://github.com/winstonjs/winston#exceptions) and [`rejectionHandlers`](https://github.com/winstonjs/winston#rejections). For example:

```ts theme={null}
import winston from 'winston';
import { WinstonTransport as AxiomTransport } from '@axiomhq/winston';
const axiomTransport = new AxiomTransport({ ... });
const logger = winston.createLogger({
  // 8<----snip----
  transports: [axiomTransport],
  exceptionHandlers: [axiomTransport],
  rejectionHandlers: [axiomTransport],
  // 8<----snip----
});
```

<Warning>
  Running on Edge runtime isn’t supported.
</Warning>

## Examples

For more examples, see the [examples in GitHub](https://github.com/axiomhq/axiom-js/tree/main/examples/winston).