Basic configuration

node or nodes

The Elasticsearch endpoint to use.
It can be a single string or an array of strings:

node: 'http://localhost:9200'

Or it can be an object (or an array of objects) that represents the node:

node: {
  url: new URL('http://localhost:9200'),
  tls: 'tls options',
  agent: 'http agent options',
  id: 'custom node id',
  headers: { 'custom': 'headers' }
  roles: {
    master: true,
    data: true,
    ingest: true,
    ml: false
  }
}

auth

Your authentication data. You can use both basic authentication and ApiKey.
See Authentication for more details.
Default: null

Basic authentication:

auth: {
  username: 'elastic',
  password: 'changeme'
}

ApiKey authentication:

auth: {
  apiKey: 'base64EncodedKey'
}

Bearer authentication, useful for service account tokens. Be aware that it does not handle automatic token refresh:

auth: {
  bearer: 'token'
}

maxRetries

number - Max number of retries for each request.
Default: 3

requestTimeout

number - Max request timeout in milliseconds for each request.
Default: 30000

pingTimeout

number - Max ping request timeout in milliseconds for each request.
Default: 3000

sniffInterval

number, boolean - Perform a sniff operation every n milliseconds. Sniffing might not be the best solution for you, take a look here to know more.
Default: false

sniffOnStart

boolean - Perform a sniff once the client is started. Sniffing might not be the best solution for you, take a look here to know more.
Default: false

sniffEndpoint

string - Endpoint to ping during a sniff.
Default: '_nodes/_all/http'

sniffOnConnectionFault

boolean - Perform a sniff on connection fault. Sniffing might not be the best solution for you, take a look here to know more.
Default: false

resurrectStrategy

string - Configure the node resurrection strategy.
Options: 'ping', 'optimistic', 'none'
Default: 'ping'

suggestCompression

boolean - Adds accept-encoding header to every request.
Default: false

compression

string, boolean - Enables gzip request body compression.
Options: 'gzip', false
Default: false

tls

http.SecureContextOptions - tls configuraton.
Default: null

proxy

string, URL - If you are using an http(s) proxy, you can put its url here. The client will automatically handle the connection to it.
Default: null

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

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

agent

http.AgentOptions, function - http agent options, or a function that returns an actual http agent instance. If you want to disable the http agent use entirely (and disable the keep-alive feature), set the agent to false.
Default: null

const client = new Client({
  node: 'http://localhost:9200',
  agent: { agent: 'options' }
})

const client = new Client({
  node: 'http://localhost:9200',
  // the function takes as parameter the option
  // object passed to the Connection constructor
  agent: (opts) => new CustomAgent()
})

const client = new Client({
  node: 'http://localhost:9200',
  // Disable agent and keep-alive
  agent: false
})

nodeFilter

function - Filters which node not to use for a request.
Default:

function defaultNodeFilter (node) {
  // avoid master only nodes
  if (node.roles.master === true &&
      node.roles.data === false &&
      node.roles.ingest === false) {
    return false
  }
  return true
}

nodeSelector

function - custom selection strategy.
Options: 'round-robin', 'random', custom function
Default: 'round-robin'
Custom function example:

function nodeSelector (connections) {
  const index = calculateIndex()
  return connections[index]
}

generateRequestId

function - function to generate the request id for every request, it takes two parameters, the request parameters and options.
By default it generates an incremental integer for every request.
Custom function example:

function generateRequestId (params, options) {
  // your id generation logic
  // must be syncronous
  return 'id'
}

name

string, symbol - The name to identify the client instance in the events.
Default: elasticsearch-js

opaqueIdPrefix

string - A string that will be use to prefix any X-Opaque-Id header.
See https://www.elastic.co/guide/en/elasticsearch/client/javascript-api/current/observability.html#x-opaque-id_support[X-Opaque-Id support] for more details.
_Default: null

headers

object - A set of custom headers to send in every request.
Default: {}

context

object - A custom object that you can use for observability in your events. It will be merged with the API level context option.
Default: null

enableMetaHeader

boolean - If true, adds an header named 'x-elastic-client-meta', containing some minimal telemetry data, such as the client and platform version.
Default: true

cloud

object - Custom configuration for connecting to Elastic Cloud. See Authentication for more details.
Default: null
Cloud configuration example:

const client = new Client({
  cloud: {
    id: '<cloud-id>'
  },
  auth: {
    username: 'elastic',
    password: 'changeme'
  }
})

disablePrototypePoisoningProtection

boolean, 'proto', 'constructor' - By the default the client will protect you against prototype poisoning attacks. Read this article to learn more. If needed you can disable prototype poisoning protection entirely or one of the two checks. Read the secure-json-parse documentation to learn more.
Default: false

caFingerprint

string - If configured, verify that the fingerprint of the CA certificate that has signed the certificate of the server matches the supplied fingerprint. Only accepts SHA256 digest fingerprints.
Default: null

maxResponseSize

number - When configured, it verifies that the uncompressed response size is lower than the configured number, if it’s higher it will abort the request. It cannot be higher than buffer.constants.MAX_STRING_LENGTH
Default: null

maxCompressedResponseSize

number - When configured, it verifies that the compressed response size is lower than the configured number, if it’s higher it will abort the request. It cannot be higher than buffer.constants.MAX_LENGTH
Default: null