---
title: Other authentication methods in the Elasticsearch Java REST client
description: If you want the client to authenticate with an Elasticsearch access token, set the relevant HTTP request header. If the client makes requests on behalf...
url: https://docs-v3-preview.elastic.dev/elastic/elasticsearch-java/pull/1224/reference/transport/rest-client/config/other_authentication_methods
products:
  - Elasticsearch
  - Elasticsearch Client
---

# Other authentication methods in the Elasticsearch Java REST client
<note>
  This is the legacy RestClient. Please migrate to [Rest5Client](https://docs-v3-preview.elastic.dev/elastic/elasticsearch-java/pull/1224/reference/transport/rest5-client), a drop-in replacement with an up-to-date http library.
</note>


## Elasticsearch Token Service tokens

If you want the client to authenticate with an Elasticsearch access token, set the relevant HTTP request header. If the client makes requests on behalf of a single user only, you can set the necessary `Authorization` header as a default header as shown in the following example:
```java
RestClientBuilder builder = RestClient.builder(
    new HttpHost("localhost", 9200, "http"));
Header[] defaultHeaders =
    new Header[]{new BasicHeader("Authorization",
        "Bearer u6iuAxZ0RG1Kcm5jVFI4eU4tZU9aVFEwT2F3")};
builder.setDefaultHeaders(defaultHeaders);
```


## Elasticsearch API keys

If you want the client to authenticate with an Elasticsearch API key, set the relevant HTTP request header. If the client makes requests on behalf of a single user only, you can set the necessary `Authorization` header as a default header as shown in the following example:
```java
String apiKeyId = "uqlEyn8B_gQ_jlvwDIvM";
String apiKeySecret = "HxHWk2m4RN-V_qg9cDpuX";
String apiKeyAuth =
    Base64.getEncoder().encodeToString(
        (apiKeyId + ":" + apiKeySecret)
            .getBytes(StandardCharsets.UTF_8));
RestClientBuilder builder = RestClient.builder(
    new HttpHost("localhost", 9200, "http"));
Header[] defaultHeaders =
    new Header[]{new BasicHeader("Authorization",
        "ApiKey " + apiKeyAuth)};
builder.setDefaultHeaders(defaultHeaders);
```