Write data with the InfluxDB v2 JavaScript client library

Use the InfluxDB v2 Javascript client library to write data from a Node.js environment to InfluxDB.

The Javascript client library includes the following convenient features for writing data to InfluxDB:

• Apply default tags to data points.
• Buffer points into batches to optimize data transfer.
• Automatically retry requests on failure.
• Set an optional HTTP proxy address for your network.

Before you begin

• Install the client library and other dependencies.

Write data with the client library

1. Instantiate a client by calling the new InfluxDB() constructor with your InfluxDB URL and API token (environment variables you already set in the Install section).

   import {InfluxDB, Point} from '@influxdata/influxdb-client'
   
   const influxDB = new InfluxDB({url: process.env.INFLUX_URL,
                                  token: process.env.INFLUX_TOKEN})
   

2. Use the getWriteApi() method of the client to create a write client. Provide your InfluxDB organization ID and bucket name.

const writeApi = influxDB.getWriteApi(process.env.INFLUX_ORG, process.env.INFLUX_BUCKET)

3. To apply one or more [tags](/influxdb/cloud-serverless/reference/glossary/#tag) to all points, use the `useDefaultTags()` method.
Provide tags as an object of key/value pairs.

 ```js
 writeApi.useDefaultTags({region: 'west'})
 ```

4. Use the `Point()` constructor to create a [point](/influxdb/cloud-serverless/reference/glossary/#point).
1. Call the constructor and provide a [measurement](/influxdb/cloud-serverless/reference/glossary/#measurement).
2. To add one or more tags, chain the `tag()` method to the constructor.
   Provide a `name` and `value`.
3. To add a field of type `float`, chain the `floatField()` method to the constructor.
   Provide a `name` and `value`.

 ```js
 const point1 = new Point('temperature')
   .tag('sensor_id', 'TLM010')
   .floatField('value', 24)
 ```

5. Use the `writePoint()` method to write the point to your InfluxDB bucket.
Finally, use the `close()` method to flush all pending writes.
The example logs the new data point followed by "WRITE FINISHED" to stdout.

 ```js
 writeApi.writePoint(point1)

 writeApi.close().then(() => {
   console.log('WRITE FINISHED')
 })
 ```

### Complete example

```js
'use strict'
/** @module write
* Writes a data point to InfluxDB using the Javascript client library with Node.js.
**/

import {InfluxDB, Point} from '@influxdata/influxdb-client'

/**
* Instantiate the InfluxDB client.
* Provide your InfluxDB URL and API token.
**/
const influxDB = new InfluxDB({url: process.env.INFLUX_URL,
                           token: process.env.INFLUX_TOKEN})

/**
* Create a write client from the getWriteApi method.
* Provide your org and bucket.
**/
const writeApi = influxDB.getWriteApi(process.env.INFLUX_ORG,
                                   process.env.INFLUX_BUCKET)

/**
* Apply default tags to all points.
**/
writeApi.useDefaultTags({region: 'west'})

/**
* Create a point and write it to the buffer.
**/
const point1 = new Point('temperature')
.tag('sensor_id', 'TLM01')
.floatField('value', 24.0)
console.log(` ${point1}`)

writeApi.writePoint(point1)

/**
* Flush pending writes and close writeApi.
**/
writeApi.close().then(() => {
console.log('WRITE FINISHED')
})

In your terminal with environment variables or env.js set, run the following command to execute the JavaScript file:

node write.js

Response codes

For information about InfluxDB API response codes, see InfluxDB API Write documentation.