Quick startedit

First of all, require the client and initialize it:

const { Client } = require('@elastic/elasticsearch')
const client = new Client({ node: 'http://localhost:9200' })

You can use both the callback-style API and the promise-style API, both behave the same way.

// promise API
const result = await client.search({
  index: 'my-index',
  body: {
    query: {
      match: { hello: 'world' }
    }
  }
})

// callback API
client.search({
  index: 'my-index',
  body: {
    query: {
      match: { hello: 'world' }
    }
  }
}, (err, result) => {
  if (err) console.log(err)
})

The returned value of every API call is formed as follows:

{
  body: object | boolean
  statusCode: number
  headers: object
  warnings: [string]
  meta: object
}

Let’s see a complete example!

'use strict'

const { Client } = require('@elastic/elasticsearch')
const client = new Client({ node: 'http://localhost:9200' })

async function run () {
  // Let's start by indexing some data
  await client.index({
    index: 'game-of-thrones',
    // type: '_doc', // uncomment this line if you are using Elasticsearch ≤ 6
    body: {
      character: 'Ned Stark',
      quote: 'Winter is coming.'
    }
  })

  await client.index({
    index: 'game-of-thrones',
    // type: '_doc', // uncomment this line if you are using Elasticsearch ≤ 6
    body: {
      character: 'Daenerys Targaryen',
      quote: 'I am the blood of the dragon.'
    }
  })

  await client.index({
    index: 'game-of-thrones',
    // type: '_doc', // uncomment this line if you are using Elasticsearch ≤ 6
    body: {
      character: 'Tyrion Lannister',
      quote: 'A mind needs books like a sword needs a whetstone.'
    }
  })

  // here we are forcing an index refresh, otherwise we will not
  // get any result in the consequent search
  await client.indices.refresh({ index: 'game-of-thrones' })

  // Let's search!
  const { body } = await client.search({
    index: 'game-of-thrones',
    // type: '_doc', // uncomment this line if you are using Elasticsearch ≤ 6
    body: {
      query: {
        match: { quote: 'winter' }
      }
    }
  })

  console.log(body.hits.hits)
}

run().catch(console.log)

Install multiple versionsedit

If you are using multiple versions of Elasticsearch, you need to use multiple versions of the client.
In the past, install multiple versions of the same package was not possible, but with npm v6.9, you can do that via aliasing.

If you are using multiple versions of Elasticsearch, you need to use multiple versions of the client as well. In the past, installing multiple versions of the same package was not possible, but with npm v6.9, you can do it via aliasing.

To install different version of the client, run the following command:

npm install <alias>@npm:@elastic/elasticsearch@<version>

So for example if you need to install 7.x and 6.x, you will run

npm install es6@npm:@elastic/elasticsearch@6
npm install es7@npm:@elastic/elasticsearch@7

And your package.json will look like the following:

"dependencies": {
  "es6": "npm:@elastic/elasticsearch@^6.7.0",
  "es7": "npm:@elastic/elasticsearch@^7.0.0"
}

You will require the packages from your code by using the alias you have defined.

const { Client: Client6 } = require('es6')
const { Client: Client7 } = require('es7')

const client6 = new Client6({ node: 'http://localhost:9200' })
const client7 = new Client7({ node: 'http://localhost:9201' })

client6.info(console.log)
client7.info(console.log)

Finally, if you want to install the client for the next version of Elasticsearch (the one that lives in the Elasticsearch master branch), use the following command:

npm install esmaster@github:elastic/elasticsearch-js

This command installs the master branch of the client which is not considered stable.