Release notesedit


Breaking changesedit

Remove Node.js v8 support #1402edit

According to our support matrix.


Support for Elasticsearch v7.12edit

You can find all the API changes here.

Add support for transport options to all helpers #1400edit

You can now pass Transport specific options to the helpers as well.


Add .finally method to the Promise API #1415edit

The client returns a thenable object when you are not configuring a callback. Now the thenable offers a .finally method as well.



Support for Elasticsearch v7.11edit

You can find all the API changes here.

Added new observability events #1365edit

Two new observability events has been introduced: serialization and deserialization. The event order is described in the following graph, in some edge cases, the order is not guaranteed. You can find in test/acceptance/events-order.test.js how the order changes based on the situation.

  │ (serialization and compression happens between those two events)
  └─▶ request
        │ (actual time spent over the wire)
        └─▶ deserialization
              │ (deserialization and decompression happens between those two events)
              └─▶ response
Added x-elastic-client-meta header #1373edit

Adds the x-elastic-client-meta HTTP header which is used by Elastic Cloud and can be disabled with the enableMetaHeader parameter set to false.


Fixes req.abort() with a body that is a stream calls callback(err) twice #1376edit

When using a body that is a stream to, and calling req.abort(), the callback is called twice. Once for the RequestAbortedError, as expected, and once for a "premature close" error from end-of-stream, used by pump, used by the client. This issue has now been fixed.



Support for Elasticsearch v7.10.edit

You can find all the API changes here.

Added proxy support #1260edit

If you need to pass through an http(s) proxy for connecting to Elasticsearch, the client offers out of the box a handy configuration for helping you with it. Under the hood it uses the hpagent module.

const client = new Client({
  node: 'http://localhost:9200',
  proxy: 'http://localhost:8080'

Basic authentication is supported as well:

const client = new Client({
  node: 'http://localhost:9200',
  proxy: 'http://user:pwd@localhost:8080'


Scroll search should clear the scroll at the end #1331edit

From now on the scroll search helper will automatically close the scroll on Elasticsearch, by doing so, Elasticsearch will free resources faster.

Handle connectivity issues while reading the body #1343edit

It might happen that the underlying socket stops working due to an external cause while reading the body. This could lead to an unwanted DeserialzationError. From now, this will be handled as a generic ConnectionError.


Add warning log about nodejs version support #1349edit

7.11 will be the last version of the client that will support Node.js v8, while 7.12 will be the last one that supports Node.js v10. If you are eusing this versions you will see a DeprecationWaring in your logs. We strongly recommend to upgrade to newer versions of Node.js as usng an EOL version will expose you to securty risks.

Please refer to for additional information.



Improve child performances #1314edit

The client code has been refactored to speed up the performances of the child method. Before this pr, creating many children per second would have caused a high memory consumption and a spike in CPU usage. This pr changes the way the client is created by refactoring the code generation, now the clients methods are no longer added to the instance with a for loop but via prototypal inheritance. Thus, the overall performances are way better, now creating a child is ~5 times faster, and it consumes ~70% less memory.

This change should not cause any breaking change unless you were mocking the client methods. In such case you should refactor it, or use elasticsearch-js-mock.

Finally, this change should also fix once and of all the bundlers support.

Throw all errors asynchronously #1295edit

Some validation errors were thrown synchronously, causing the callback to be called in th same tick. This issue is known as "The release fo Zalgo" (see here).

Fix maxRetries request option handling #1296edit

The maxRetries parameter can be configured on a per requets basis, if set to zero it was defaulting to the client default. Now the client is honoring the request specific configuration.

Fix RequestOptions.body type to include null #1300edit

The Connection requets option types were not accepting null as valid value.

Fixed size and maxRetries parameters in helpers #1284edit

The size parameter was being passed too the scroll request, which was causing an error. Value of maxRetries set to 0 was resulting in no request at all.



Add ability to disable the http agent #1251edit

If needed, the http agent can be disabled by setting it to false.

const { Client } = require('@elastic/elasticsearch')
const client = new Client({
  node: 'http://localhost:9200'.
  agent: false
Add support for a global context option #1256edit

Before this, you could set a context option in each request, but there was no way of setting it globally. Now you can by configuring the context object in the global configuration, that will be merged with the local one.

const { Client } = require('@elastic/elasticsearch')
const client = new Client({
  node: 'http://localhost:9200'.
  context: { meta: 'data' }
ESM support #1235edit

If you are using ES Modules, now you can easily import the client!

import { Client } from '@elastic/elasticsearch'


Allow the client name to be a symbol #1254edit

It was possible in plain JavaScript, but not in TypeScript, now you can do it in TypeScript as well.

const { Client } = require('@elastic/elasticsearch')
const client = new Client({
  node: 'http://localhost:9200',
  name: Symbol('unique')
Fixed transport.request querystring type #1240edit

Only Record<string, any> was allowed. Now string is allowed as well.

Fixed type definitions #1263edit
  • The transport.request defintion was incorrect, it was returning a Promise<T> instead of TransportRequestPromise<T>.
  • The refresh parameter of most APIs was declared as 'true' | 'false' | 'wait_for', which was clunky. Now is 'wait_for' | boolean.
Generate response type as boolean if the request is HEAD only #1275edit

All HEAD request will have the body casted to a boolean value, true in case of a 200 response, false in case of a 404 response. The type definitions were not reflecting this behavior.

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

const { body } = await client.exist({ index: 'my-index', id: 'my-id' })
console.log(body) // either `true` or `false`


Updated default http agent configuration #1242edit

Added the scheduling: lifo option to the default HTTP agent configuration to avoid maximizing the open sockets against Elasticsearch and lowering the risk of encountering socket timeouts. This feature is only available from Node v14.5+, but it should be backported to v10 and v12 (nodejs/node#33278).

Improve child API #1245edit

This pr introduce two changes which should not impact the surface API:

  • Refactored the client.child API to allocate fewer objects, this change improves memory consumption over time and improves the child creation performances by ~12%.
  • The client no longer inherits from the EventEmitter class, but instead has an internal event emitter and exposes only the API useful for the users, namely emit, `on, once, and off. The type definitions have been updated accordingly.



Support for Elasticsearch v7.8.edit

You can find all the API changes here.

Added multi search helper #1186edit

If you are sending search request at a high rate, this helper might be useful for you. It will use the mutli search API under the hood to batch the requests and improve the overall performances of your application. The result exposes a documents property as well, which allows you to access directly the hits sources.

const { Client } = require('@elastic/elasticsearch')

const client = new Client({ node: 'http://localhost:9200' })
const m = client.helpers.msearch()

// promise style API
    { index: 'stackoverflow' },
    { query: { match: { title: 'javascript' } } }
  .then(result => console.log(result.body)) // or result.documents
  .catch(err => console.error(err))

// callback style API
  { index: 'stackoverflow' },
  { query: { match: { title: 'ruby' } } },
  (err, result) => {
    if (err) console.error(err)
    console.log(result.body)) // or result.documents
Added timeout support in bulk and msearch helpers #1206edit

If there is a slow producer, the bulk helper might send data with a very large period of time, and if the process crashes for any reason, the data would be lost. This pr introduces a flushInterval option in the bulk helper to avoid this issue. By default, the bulk helper will flush the data automatically every 30 seconds, unless the threshold has been reached before.

const b = client.helpers.bulk({
  flushInterval: 30000

The same problem might happen with the multi search helper, where the user is not sending search requests fast enough. A flushInterval options has been added as well, with a default value of 500 milliseconds.

const m = client.helpers.msearch({
  flushInterval: 500


Use filter_path for improving the search helpers performances #1199edit

From now on, all he search helpers will use the filter_path option automatically when needed to retrieve only the hits source. This change will result in less netwprk traffic and improved deserialization performances.

Search helpers documents getter #1186edit

Before this, the documents key that you can access in any search helper was computed as soon as we got the search result from Elasticsearch. With this change the documents key is now a getter, which makes this process lazy, resulting in better performances and lower memory impact.



Disable client Helpers in Node.js < 10 - #1194edit

The client helpers can’t be used in Node.js < 10 because it needs a custom flag to be able to use them. Given that not every provider allows the user to specify custom Node.js flags, the Helpers has been disabled completely in Node.js < 10.

Force lowercase in all headers - #1187edit

Now all the user-provided headers names will be lowercased by default, so there will be no conflicts in case of the same header with different casing.



Support for Elasticsearch v7.7.edit

You can find all the API changes here.

Introduced client helpers - #1107edit

From now on, the client comes with an handy collection of helpers to give you a more comfortable experience with some APIs.

The client helpers are experimental, and the API may change in the next minor releases.

The following helpers has been introduced:

  • client.helpers.bulk
  • client.helpers.scrollSearch
  • client.helpers.scrollDocuments
The ConnectionPool.getConnection now always returns a Connection - #1127edit

What does this mean? It means that you will see less NoLivingConnectionError, which now can only be caused if you set a selector/filter too strict. For improving the debugging experience, the NoLivingConnectionsError error message has been updated.

Abortable promises - #1141edit

From now on, it will be possible to abort a request generated with the promise-styl API. If you abort a request generated from a promise, the promise will be rejected with a RequestAbortedError.

const promise ={
  body: {
    query: { match_all: {} }


Major refactor of the Type Definitions - #1119 #1130 #1132edit

Now every API makes better use of the generics and overloading, so you can (or not, by default request/response bodies are Record<string, any>) define the request/response bodies in the generics.

// request and response bodies are generics
// response body is `SearchResponse` and request body is generic<SearchResponse>(...)
// request body is `SearchBody` and response body is `SearchResponse`<SearchResponse, SearchBody>(...)

This should not be a breaking change, as every generics defaults to any. It might happen to some users that the code breaks, but our test didn’t detect any of it, probably because they were not robust enough. However, given the gigantic improvement in the developer experience, we have decided to release this change in the 7.x line.


The ConnectionPool.update method now cleans the dead list - #1122 #1127edit

It can happen in a situation where we are updating the connections list and running sniff, leaving the dead list in a dirty state. Now the ConnectionPool.update cleans up the dead list every time, which makes way more sense given that all the new connections are alive.

ConnectionPoolmarkDead should ignore connections that no longer exists - #1159edit

It might happen that markDead is called just after a pool update, and in such case, the client was adding the dead list a node that no longer exists, causing unhandled exceptions later.

Do not retry a request if the body is a stream - #1143edit

The client should not retry if it’s sending a stream body, because it should store in memory a copy of the stream to be able to send it again, but since it doesn’t know in advance the size of the stream, it risks to take too much memory. Furthermore, copying everytime the stream is very an expensive operation.

Return an error if the request has been aborted - #1141edit

Until now, aborting a request was blocking the HTTP request, but never calling the callback or resolving the promise to notify the user. This is a bug because it could lead to dangerous memory leaks. From now on if the user calls the request.abort() method, the callback style API will be called with a RequestAbortedError, the promise will be rejected with RequestAbortedError as well.



  • Secure json parsing - #1110
  • ApiKey should take precedence over basic auth - #1115


  • Fix typo in api reference - #1109


Support for Elasticsearch v7.6.



  • Skip compression in case of empty string body - #1080
  • Fix typo in NoLivingConnectionsError - #1045
  • Change TransportRequestOptions.ignore to number[] - #1053
  • ClientOptions["cloud"] should have optional auth fields - #1032


  • Docs: Return super in example Transport subclass - #980
  • Add examples to reference - #1076
  • Added new examples - #1031


Support for Elasticsearch v7.5.


  • X-Opaque-Id support #997


Support for Elasticsearch v7.4.


  • Fix issue; node roles are defaulting to true when undefined is breaking usage of nodeFilter option - #967


  • Updated API reference doc - #945, #969
  • Fix inaccurate description sniffEndpoint - #959


  • Update code generation #969


Support for Elasticsearch v7.3.


  • Added auth option - #908
  • Added support for ApiKey authentication - #908


  • fix(Typings): sniffInterval can also be boolean - #914


  • Refactored connection pool - #913


  • Better reference code examples - #920
  • Improve README - #909


Support for Elasticsearch v7.2


  • Remove auth data from inspect and toJSON in connection class - #887


Support for Elasticsearch v7.1


  • Support for non-friendly chars in url username and password - #858
  • Patch deprecated parameters - #851



  • Fix TypeScript export (issue #841) - #842
  • Fix http and https port handling (issue #843) - #845
  • Fix TypeScript definiton (issue #803) - #846
  • Added toJSON method to Connection class (issue #848) - #849


Support for Elasticsearch v7.0

  • Stable release.

"appendix",role="exclude",id="redirects"] = Deleted pages

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