To send data from a JavaScript app to Axiom, use the Axiom JavaScript SDK.
The Axiom JavaScript SDK is an open-source project and welcomes your contributions. For more information, see the GitHub repository.

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Prerequisites

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Install SDK

To install the SDK, run the following: 
npm install @axiomhq/js
If you use the Axiom CLI, run eval $(axiom config export -f) to configure your environment variables. Otherwise, create an API token and export it as AXIOM_TOKEN. You can also configure the client using options passed to the constructor of the client: 
import { Axiom } from '@axiomhq/js';

const axiom = new Axiom({
  token: process.env.AXIOM_TOKEN,
});

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Send data

The following example sends data to Axiom: 
axiom.ingest('DATASET_NAME', [{ foo: 'bar' }]);
await axiom.flush();
The client automatically batches events in the background. In most cases, you only want to call flush() before your application exits.

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Query data

The following example queries data from Axiom: 
const res = await axiom.query(`['DATASET_NAME'] | where foo == 'bar' | limit 100`);
console.log(res);
For more examples, see the examples in GitHub.

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Capture errors

To capture errors, pass a method onError to the client: 
let client = new Axiom({
  token: '',
  ...,
  onError: (err) => {
    console.error('ERROR:', err);
  }
});
By default, onError is set to console.error.

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Create annotations

The following example creates an annotation: 
import { annotations } from '@axiomhq/js';

const client = new annotations.Service({ token: process.env.AXIOM_TOKEN });

await annotations.create({
  type: 'deployment',
  datasets: ['DATASET_NAME'],
  title: 'New deployment',
  description: 'Deployed version 1.0.0',
})

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Log from Node.js

While the Axiom JavaScript client works on both the backend and the browsers, Axiom provides transports for some of the popular loggers: