nexus-java-client

Java client for the Nexus Cardano data API.

Install

nexus-java-client is published to Maven Central — no extra repository needed:

<dependency>
  <groupId>io.github.gero-labs</groupId>
  <artifactId>nexus-java-client</artifactId>
  <version>1.1.0</version>
</dependency>

Usage

BackendService nexus = BackendServiceFactory.getNexusBackendService(
        "https://nexus.gerowallet.io", System.getenv("NEXUS_API_KEY"));

Result<Block> latest = nexus.getBlockService().getLatestBlock(Network.MAINNET);
if (latest.isSuccessful()) {
    System.out.println(latest.getValue().getHash());
}

Every service method returns a Result<T>: isSuccessful(), getCode(), getResponse(), getValue(). Transport failures throw ApiException.

Resources

getAccountService(), getAddressService(), getAssetService(), getBlockService(), getEpochService(), getPoolService(), getTransactionService().

Build

mvn clean test

Release

Releases publish to Maven Central under io.github.gero-labs:nexus-java-client. The tag-triggered publish.yml workflow runs this automatically; the steps below are for setting that up or running a release manually.

One-time setup:

1. Verify the io.github.gero-labs namespace with Sonatype Central (https://central.sonatype.org/register/namespace/) — it's tied to the GitHub org.
2. Generate a Central Portal user token (https://central.sonatype.com/account) and add it to ~/.m2/settings.xml:

   <servers>
     <server>
       <id>central</id>
       <username>YOUR_TOKEN_USERNAME</username>
       <password>YOUR_TOKEN_PASSWORD</password>
     </server>
   </servers>

3. Have a GPG key available for signing (gpg --gen-key if you don't have one) — Central requires all release artifacts to be signed.

To release:

mvn -Prelease deploy

This builds the jar, sources jar, and javadoc jar, signs all three with GPG, and uploads a deployment bundle to the Central Portal. The deployment lands in PENDING/VALIDATED state — sign in to https://central.sonatype.com/publishing and click Publish to make it live (this repo's autoPublish is false by design, so nothing goes live unattended).