Spring Boot SDK - Westyx Nexus

Installation

pom.xml

<dependency>
  <groupId>dev.westyx.nexus</groupId>
  <artifactId>nexus-spring-boot-starter</artifactId>
  <version>0.3.1</version>
</dependency>

Requires Java 17+ and Spring Boot 3+.

Quick start

Add to application.properties (or application.yml):

nexus.base-url=https://your-service.nexus.westyx.dev
nexus.api-key=sk_live_...

Then inject NexusClient:

@Service
public class MyService {

    private final NexusClient nexus;

    public MyService(NexusClient nexus) {
        this.nexus = nexus;
    }

    public void doWork() {
        String dbHost = nexus.getConfig("DB_HOST");
        byte[] dbPass = nexus.getSecret("DB_PASSWORD");
        String cert   = nexus.getSecretFilePath("TLS_CERT"); // temp file
        boolean newUI = nexus.getFlag("new-ui", false);
    }
}

Configuration reference

nexus.base-url=https://your-service.nexus.westyx.dev
nexus.api-key=sk_live_...
nexus.ttl=300           # seconds, default 300
nexus.wif.enabled=true  # Workload Identity Federation
nexus.wif.provider=auto # kubernetes | aws | gcp | azure | auto

API

Method	Returns	Description
`getConfig(key)`	`String`	Config value or null
`getConfigAs(key, type)`	`T`	Typed config
`getConfigJson(key)`	`Object`	Parsed JSON config
`getSecret(key)`	`byte[]`	Secret bytes; throws on pk_ key or frontend kind
`getSecretFilePath(key)`	`String`	Temp file path for file-type secrets
`getFlag(key, default)`	`boolean`	Flag value; default if not found
`evaluateAb(keys, userId, attrs)`	`Map<String,Boolean>`	A/B evaluation

Workload Identity Federation

nexus.wif.enabled=true
nexus.wif.provider=kubernetes

Or configure via @Bean:

@Bean
public NexusConfig nexusConfig() {
    return NexusConfig.builder()
        .baseUrl("https://your-service.nexus.westyx.dev")
        .wif(WifConfig.builder().enabled(true).provider("auto").build())
        .build();
}

SSE live updates

The starter automatically starts the SSE stream on application startup and tears it down on close(). No additional configuration required.

Error types

Exception	Cause
`NexusPublicKeyException`	`getSecret` with `pk_live_` key
`NexusServiceKindMismatchException`	`getSecret` on `kind=frontend` service
`NexusBillingException`	402 - billing blocked
`NexusWifTokenExchangeException`	Server rejected the OIDC token

Documentation Index

​Installation

​Quick start

​Configuration reference

​API

​Workload Identity Federation

​SSE live updates

​Error types