Elasticsearch Authentication

Authenticate to an Elasticsearch cluster using any supported authentication realm that is already configured. This skill covers all built-in realms, credential verification, and the full API key lifecycle.

For roles, users, role assignment, and role mappings, see the elasticsearch-authz skill.

For detailed API endpoints, see references/api-reference.md.

Deployment note: Not all realms are available on every deployment type. See Deployment Compatibility for self-managed vs. ECH vs. Serverless details.

Critical principles

• Never ask for credentials in chat. Do not ask the user to paste passwords, API keys, tokens, or any secret into the conversation. Secrets must not appear in conversation history.
• Always use environment variables. All code examples in this skill reference environment variables (e.g. ELASTICSEARCH_PASSWORD, ELASTICSEARCH_API_KEY). When a required variable is missing, instruct the user to set it in a .env file in the project root — never prompt for the value directly.
• Prefer .env over terminal exports. Agents may run commands in a sandboxed shell session that does not inherit the user's terminal environment. A .env file in the working directory is reliable across all execution contexts. Only suggest export as a fallback when the user explicitly prefers it.

Jobs to Be Done

• Authenticate to a cluster using username and password (native realm)
• Connect using an API key (bearer token)
• Verify who is currently authenticated (_authenticate)
• Choose the right authentication realm for a deployment
• Create an API key with scoped privileges for automation or service access
• Rotate or invalidate an existing API key
• Set up service account tokens for Elastic stack components
• Authenticate with PKI / mutual TLS certificate-based authentication after PKI/TLS setup
• Authenticate with configured external identity providers (SAML, OIDC, LDAP, AD, Kerberos)
• Grant API keys on behalf of other users

Prerequisites

Item	Description
Elasticsearch URL	Cluster endpoint (e.g. https://localhost:9200 or a Cloud deployment URL)
Credentials	Depends on the realm — see the methods below
Realms configured	Authentication realms and their identity backends must already be configured (realm chain, IdP, LDAP/AD, Kerberos, PKI/TLS)

If any required value is missing, instruct the user to add it to a .env file in the project root. Terminal exports may not be visible to agents running in a separate shell session — the .env file is the reliable default. Never ask the user to paste credentials into the chat — secrets must not appear in conversation history.

Authentication Realms

Elasticsearch evaluates realms in a configured order (the realm chain). The first realm that can authenticate the request wins. Internal realms are managed by Elasticsearch; external realms delegate to enterprise identity systems.

Internal realms

Native (username and password)

Users stored in a dedicated Elasticsearch index. Simplest method for interactive use. Managed via Kibana or the user management APIs (see the elasticsearch-authz skill).

curl -u "${ELASTICSEARCH_USERNAME}:${ELASTICSEARCH_PASSWORD}" "${ELASTICSEARCH_URL}/_security/_authenticate"

File

Users defined in flat files on each cluster node (elasticsearch-users CLI). Always active regardless of license state, making it the fallback for disaster recovery when paid realms are disabled. Only available on self-managed deployments.

curl -u "${FILE_USER}:${FILE_PASSWORD}" "${ELASTICSEARCH_URL}/_security/_authenticate"

External realms

LDAP

Authenticates against an external LDAP directory using username and password. Self-managed only — not available on ECH or Serverless. Typically combined with role mappings to translate LDAP groups to Elasticsearch roles.

curl -u "${LDAP_USER}:${LDAP_PASSWORD}" "${ELASTICSEARCH_URL}/_security/_authenticate"

The request is identical to native — Elasticsearch routes it to the LDAP realm via the realm chain.

Active Directory

Authenticates against an Active Directory domain. Self-managed only — not available on ECH or Serverless. Similar to LDAP but uses AD-specific defaults (user principal name, sAMAccountName). Typically combined with role mappings for AD group-to-role translation.

curl -u "${AD_USER}:${AD_PASSWORD}" "${ELASTICSEARCH_URL}/_security/_authenticate"

PKI (TLS client certificates)

Authenticates using X.509 client certificates presented during the TLS handshake. Requires a PKI realm and TLS on the HTTP layer. On ECH, PKI support is limited — check deployment settings. Not available on Serverless. Best for service-to-service communication in mutual TLS environments.

curl --cert "${CLIENT_CERT}" --key "${CLIENT_KEY}" --cacert "${CA_CERT}" \
  "${ELASTICSEARCH_URL}/_security/_authenticate"

SAML

Enables SAML 2.0 Web Browser SSO, primarily for Kibana authentication. On self-managed, configure in elasticsearch.yml. On ECH, configure through the Cloud deployment settings UI. On Serverless, SAML is handled at the organization level and not configurable per project. Not usable by standard REST clients — the browser-based redirect flow is handled by Kibana. Configure another realm (e.g. native or API keys) alongside SAML for programmatic API access.

OIDC (OpenID Connect)

Enables OpenID Connect SSO, primarily for Kibana authentication. On self-managed, configure in elasticsearch.yml. On ECH, configure through the Cloud deployment settings UI. Not available on Serverless. Like SAML, it relies on browser redirects and is not suited for direct REST client use. For programmatic access alongside OIDC, use API keys or native users.

Custom applications can exchange OIDC tokens for Elasticsearch access tokens via POST /_security/oidc/authenticate, but this requires implementing the full OIDC redirect flow.

JWT (JSON Web Tokens)

Accepts JWTs issued by an external identity provider as bearer tokens. On self-managed, configure in elasticsearch.yml. On ECH, configure through the Cloud deployment settings UI. Not available on Serverless. Supports two token types:

• id_token (default) — OpenID Connect ID tokens for user-on-behalf-of flows.
• access_token — OAuth2 client credentials for application identity flows.

curl -H "Authorization: Bearer ${JWT_TOKEN}" "${ELASTICSEARCH_URL}/_security/_authenticate"

Each JWT realm handles one token type. Configure separate realms for id_token and access_token if both are needed.

Kerberos

Authenticates using Kerberos tickets via the SPNEGO mechanism. Self-managed only — not available on ECH or Serverless. Requires a working KDC infrastructure, proper DNS, and time synchronization.

kinit "${KERBEROS_PRINCIPAL}"
curl --negotiate -u : "${ELASTICSEARCH_URL}/_security/_authenticate"

The --negotiate flag enables SPNEGO. The -u : is required by curl but the username is ignored — the principal from kinit is used. Requires curl 7.49+ with GSS-API/SPNEGO support.

API keys

Not a realm, but a distinct authentication mechanism. Pass a Base64-encoded API key in the Authorization header. Preferred for programmatic and automated access.

curl -H "Authorization: ApiKey ${ELASTICSEARCH_API_KEY}" "${ELASTICSEARCH_URL}/_security/_authenticate"

ELASTICSEARCH_API_KEY is the encoded value (Base64 of id:api_key) returned when the key was created.

Verify authentication

Always verify credentials before proceeding:

curl <auth_flags> "${ELASTICSEARCH_URL}/_security/_authenticate"

Check username, roles, and authentication_realm.type to confirm identity and method:

authentication_realm.type	Realm
native	Native
file	File
ldap	LDAP
active_directory	Active Directory
pki	PKI
saml	SAML
oidc	OpenID Connect
jwt	JWT
kerberos	Kerberos

For API keys, authentication_type is "api_key" (not a realm type).

Manage API Keys

Create an API key

curl -X POST "${ELASTICSEARCH_URL}/_security/api_key" \
  <auth_flags> \
  -H "Content-Type: application/json" \
  -d '{
    "name": "'"${KEY_NAME}"'",
    "expiration": "30d",
    "role_descriptors": {
      "'"${ROLE_NAME}"'": {
        "cluster": [],
        "indices": [
          {
            "names": ["'"${INDEX_PATTERN}"'"],
            "privileges": ["read"]
          }
        ]
      }
    }
  }'

The response contains id, api_key, and encoded. Store encoded securely — it cannot be retrieved again.

Omit role_descriptors to inherit a snapshot of the authenticated user's current privileges.

Limitation: An API key cannot create another API key with privileges. The derived key is created with no effective access. Use POST /_security/api_key/grant with user credentials instead.

Get and invalidate API keys

curl "${ELASTICSEARCH_URL}/_security/api_key?name=${KEY_NAME}" <auth_flags>
curl -X DELETE "${ELASTICSEARCH_URL}/_security/api_key" \
  <auth_flags> \
  -H "Content-Type: application/json" \
  -d '{"name": "'"${KEY_NAME}"'"}'

Examples

Create a scoped API key

Request: "Create an API key that can only read from metrics-*."

POST /_security/api_key
{
  "name": "metrics-reader-key",
  "expiration": "90d",
  "role_descriptors": {
    "metrics-reader": {
      "indices": [
        {
          "names": ["metrics-*"],
          "privileges": ["read", "view_index_metadata"]
        }
      ]
    }
  }
}

Verify which realm authenticated the user

GET /_security/_authenticate

{
  "username": "joe",
  "authentication_realm": { "name": "ldap1", "type": "ldap" },
  "authentication_type": "realm"
}

Authenticate with a JWT bearer token

curl -H "Authorization: Bearer ${JWT_TOKEN}" "https://my-cluster:9200/_security/_authenticate"

Confirm the response shows authentication_realm.type as "jwt".

Guidelines

Choosing an authentication method

Method	Best for	Trade-offs
Native user	Interactive use, simple setups	Password must be stored or prompted
File user	Disaster recovery, bootstrap	Must be configured on every node
API key	Programmatic access, CI/CD, scoped access	Cannot be retrieved after creation
LDAP / AD	Enterprise directory integration	Requires network access to directory server
PKI certificate	Service-to-service, mutual TLS environments	Requires PKI infrastructure and PKI realm
SAML	Kibana SSO via enterprise IdP	Browser-only; not for REST clients
OIDC	Kibana SSO via OpenID Connect provider	Browser-only; not for REST clients
JWT	Token-based service and user authentication	Requires external token issuer and realm config
Kerberos	Windows/enterprise Kerberos environments	Requires KDC, DNS, time sync infrastructure

Prefer API keys for automated workflows — they support fine-grained scoping and independent expiration. For Kibana SSO, use SAML or OIDC. For enterprise directory integration, use LDAP or AD with role mappings (see elasticsearch-au