# Installation

The Ratepay Java SDK is published as a Maven artifact under the group ID `com.ratepay.sdk`.

## Add the dependency

Maven

```xml pom.xml
<dependency>
    <groupId>com.ratepay.sdk</groupId>
    <artifactId>ratepay-sdk-core</artifactId>
    <version>1.16.1</version>
</dependency>
```

Gradle (Kotlin DSL)

```kotlin build.gradle.kts
dependencies {
    implementation("com.ratepay.sdk:ratepay-sdk-core:1.16.1")
}
```

Gradle (Groovy DSL)

```groovy build.gradle
dependencies {
    implementation 'com.ratepay.sdk:ratepay-sdk-core:1.16.1'
}
```

## Verifying the install

To verify that the SDK is installed and your credentials are working, initialize a `RatepayClient` and call `validateCredentials()`. This method requests or reuses an OAuth access token to verify authentication without initiating a payment.

For instructions on initializing the client and managing authentication, see [Client configuration](/docs/developer/sdk/client/client-configuration) and
[Authentication](/docs/developer/sdk/client/authentication).