Publish your Scala Libraries to a Maven Repository

1. add a dependency on bazel-distribution repo from graknlabs

    name = "graknlabs_bazel_distribution",
    remote = "",
    commit = "e181add439dc1cfb7b1c27db771ec741d5dd43e6"

2. add aggregate targets

for each artifact you want to publish to maven central, create an aggregate scala_library target that includes sources for all finer-grained targets (if you have targets with coarse-grained granularity you can skip this step)

    name = "greyhound-core",
    srcs = [
    tags = ["maven_coordinates=com.wix:greyhound-core_2.12:{pom_version}"],
    visibility = ["//:__subpackages__"],
    deps = [

A few notes:

  1. All the labels in srcs are actually filegroup with appropriate visibility settings that allow out-of-package dependency:
   name = "sources",
   srcs = glob(["*.java"]) + glob(["*.scala"]),
   visibility = ["//core:__subpackages__"],
  1. There is a special maven_coordinates tag that helps the assemble_maven rule to fill-in details in the pom file.
  2. You also have to add a maven_coordinates tag to the 3rd party dependencies (such as dev_zio_zio_2_12 in the deps attribute of the example above) so that they will appear as dependencies in the pom file.

3. Add assemble_maven target

Add assemble_maven target for each artifact you want to publish. It will create all the necessary files for your artifact, including main jar, source jar and pom file. Enter all project details for the pom file.

load("@graknlabs_bazel_distribution//maven/templates:rules.bzl", "deploy_maven", "assemble_maven")

    name = "assemble-maven",
    target = "//core:greyhound-core",
    package = "{maven_packages}",
    project_name = "Greyhound Core",
    project_description = "Greyhound - Rich Kafka Client with ZIO API",
    project_url = "",
    scm_url = "",
    version_file = "//central-sync:VERSION",
    developers = {"1": ["name=Natan Silnitsky", "email=n...@w...m", "organization=Wix"]},
    license = "mit"


  1. For the target attribute you should put the label for the scala_library target you created in the previous step with all the relevant sources.
  2. Make sure the project_name and project_description are unique for each of these targets/artifacts
  3. The VERSION file just contains the SEMVER, e.g. 1.0.0
  4. Currently supported licenses include apache and MIT

4. Add deploy_maven target

Add deploy_maven target for each artifact you want to publish. The file should contain the url for the sonatype stating area: repo.maven.release=

5. Build the assemble_maven target

Build the assemble_maven target and review the generated pom file and jar file in the bazel-bin directory. Change the targets configuration as needed.

For more specific information on publishing to Maven Central repository, see this blog post