Introduction

This is the official Node.js client for Elasticsearch. This page gives a quick overview about the features of the client.

Refer to this page for breaking changes coming from the old client.

Features

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One-to-one mapping with REST API.
Generalized, pluggable architecture.
Configurable, automatic discovery of cluster nodes.
Persistent, Keep-Alive connections.
Load balancing across all available nodes.
Child client support.
TypeScript support out of the box.

Quick start

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First of all, require, then initialize the client:

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

You can use both the callback API and the promise 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 {es} ≤ 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 {es} ≤ 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 {es} ≤ 6
    body: {
      character: 'Tyrion Lannister',
      quote: 'A mind needs books like a sword needs a whetstone.'
    }
  })

  // We need to force an index refresh at this point, 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 {es} ≤ 6
    body: {
      query: {
        match: { quote: 'winter' }
      }
    }
  })

  console.log(body.hits.hits)
}

run().catch(console.log)

For an elaborate example of how to ingest data into Elastic Cloud, refer to this page.

Install multiple versions

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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>

For example, if you need to install 7.x and 6.x, run the following commands:

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

Your package.json will look similar to the following example:

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

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.

Breaking changes coming from the old client »