Maven Central

Kreate uses the Gradle Maven Publish Plugin by Vanniktech to publish to Maven Central. When enabled, Kreate configures coordinates, signing, and POM metadata from your kreate { } block — no manual mavenPublishing { } block is required.

Prerequisites

Before publishing to Maven Central, you need:

A Central Portal account at central.sonatype.com
A registered namespace (your group, e.g. com.example) verified in the portal
A GPG key pair for signing artifacts

Create a GPG key pair and distribute the public key to a keyserver:

gpg --gen-key
gpg --keyserver keyserver.ubuntu.com --send-keys <keyId>

Enabling Maven Central

Calling repositories { mavenCentral { } } automatically sets enabled = true for the Maven Central target:

kreate {
    project {
        publish {
            enabled.set(true)

            repositories {
                mavenCentral {
                    // automaticRelease and signPublications default to true
                }
            }
        }
    }
}

Maven Central Properties

Property	Type	Default	Description
`enabled`	`Property<Boolean>`	`false`	Activates the Maven Central publish target (set automatically when using the `mavenCentral { }` block)
`automaticRelease`	`Property<Boolean>`	`true`	When `true`, runs `publishAndReleaseToMavenCentral`; when `false`, only uploads — manual release required on the portal
`signPublications`	`Property<Boolean>`	`true`	Calls `signAllPublications()` — required by Maven Central for releases

`automaticRelease`

When true, Kreate passes automaticRelease = true to publishToMavenCentral(). The Vanniktech plugin then:

Uploads the artifacts to a new deployment
Polls the deployment status every 5 seconds until it reaches VALIDATED or FAILED
Automatically releases the deployment to Maven Central

The validation timeout is 60 minutes by default. After a successful release, artifacts become available in Maven Central within 10–30 minutes.

When false, the plugin only uploads the deployment. Go to Deployments on the Central Portal and click Publish manually afterward.

`signPublications`

Signing is a hard requirement for Maven Central releases. Kreate calls signAllPublications() when this is true. Set it to false only for snapshot publishing where signing is not required.

Gradle Tasks

Task	Description
`publishToMavenCentral`	Uploads artifacts; releases automatically if `automaticRelease = true`
`publishAndReleaseToMavenCentral`	Always uploads and releases, ignoring the `automaticRelease` setting

./gradlew publishToMavenCentral

Credentials and Signing

Local (`~/.gradle/gradle.properties`)

mavenCentralUsername=your_token_username
mavenCentralPassword=your_token_password

signing.keyId=12345678
signing.password=your_gpg_passphrase
signing.secretKeyRingFile=/Users/you/.gnupg/secring.gpg

CI — In-Memory GPG Signing

For CI environments, use in-memory signing to avoid placing private key files on the build agent. The Vanniktech plugin reads the private key directly from a Gradle property.

Step 1 — Export only the Base64 key content:

gpg --export-secret-keys --armor <keyId> \
  | grep -v '\-\-\-\-\-' \
  | grep -v '^=' \
  | grep -v '^$' \
  | tr -d '\n'

This strips the -----BEGIN PGP PRIVATE KEY BLOCK-----/-----END PGP PRIVATE KEY BLOCK----- headers, the =checksum trailer line, and all blank lines, leaving only the raw Base64 content.

Step 2 — Store as a masked CI/CD variable:

Store the single-line Base64 output as GPG_PRIVATE_KEY in your pipeline settings under Settings → CI/CD → Variables. Enable Masked to prevent it from appearing in logs.

Step 3 — Set Gradle properties in the pipeline:

ORG_GRADLE_PROJECT_mavenCentralUsername=$MAVEN_CENTRAL_USERNAME
ORG_GRADLE_PROJECT_mavenCentralPassword=$MAVEN_CENTRAL_PASSWORD

ORG_GRADLE_PROJECT_signingInMemoryKey=$GPG_PRIVATE_KEY
ORG_GRADLE_PROJECT_signingInMemoryKeyId=12345678        # optional
ORG_GRADLE_PROJECT_signingInMemoryKeyPassword=$GPG_KEY_PASSWORD

signingInMemoryKeyId is optional — only needed when the keyring contains multiple keys and you want to target a specific one.

Coordinates

Kreate derives the Maven coordinates automatically from your kreate { project { } } block:

Coordinate	Source	Fallback
`group`	`projectGroup`	Gradle `project.group`
`artifactId`	`name`	Gradle `project.name`
`version`	`version` Gradle property	—

Snapshot Publishing

Set the project version to end in -SNAPSHOT and run: