diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4ec2c96cd..b2c115b82 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -14,23 +14,34 @@ include:
       - templates/global/full.yaml
       - templates/python/full.yaml
 
-variables:
-  BASE_CONTAINER_VERSION: "1.4.0"
-  PRE_COMMIT_DOCKER_IMAGE: docker.osdc.io/ncigdc/python3.7-builder:2.2.0
-  DOCKER_BUILDKIT: 1
-  PIP_EXTRA_INDEX_URL: https://nexus.osdc.io/repository/pypi-all/simple
-  DOCKER_BUILD_OPTS: "--build-arg PIP_EXTRA_INDEX_URL=https://nexus.osdc.io/repository/pypi-all/simple"
-  DOCKER_PUSH_OPTS: "--all-tags"
-  TWINE_REPOSITORY_URL: "https://nexus.osdc.io/repository/pypi-snapshots/"
+tox:
+  stage: test
+  image: ${BASE_CONTAINER_REGISTRY}/python${REPO_PY_VERSION}-builder:${BASE_CONTAINER_VERSION}
+  parallel:
+    matrix:
+      - REPO_PY_VERSION: ["3.7", "3.8", "3.9"]
+  script:
+    - pip install tox
+    - tox -e ${REPO_PY_VERSION}
+
+tox legacy:
+  stage: test
+  image: ${BASE_CONTAINER_REGISTRY}/python36-builder:${LEGACY_BASE_CONTAINER_VERSION}
+  script:
+    - pip install tox
+    - tox -e py36
 
+# These rules determine when the plaster steps execute.
 .override_gdcdictionary_version:
   rules:
     - if: $GDCDICTIONARY_TARGET_VERSION_OVERRIDE != null
       variables:
         GDCDICTIONARY_TARGET_VERSION: $GDCDICTIONARY_TARGET_VERSION_OVERRIDE
-    - when: always
+    - if: $CI_COMMIT_TAG != null
       variables:
-        GDCDICTIONARY_TARGET_VERSION: $CI_COMMIT_REF_NAME
+        GDCDICTIONARY_TARGET_VERSION: $CI_COMMIT_TAG
+    - if: $CI_COMMIT_REF_NAME =~ /^(master|main|release)/
+      when: never
 
 update_reqs_for_gdcdatamodel2:
   image: docker.osdc.io/ncigdc/python36-builder:1.4.0
@@ -54,8 +65,6 @@ update_reqs_for_gdcdatamodel2:
   rules:
     - !reference [.override_gdcdictionary_version, rules]
 
-
-
 execute_plaster:
   image: docker.osdc.io/ncigdc/python3.8-builder:2.1.0
   stage: build
@@ -79,6 +88,35 @@ execute_plaster:
   rules:
     - !reference [.override_gdcdictionary_version, rules]
 
+release_datamodels_to_nexus:
+  image: docker.osdc.io/ncigdc/python36-builder:1.4.0
+  stage: release_gdcdatamodel2
+  script:
+    - cd gdcdatamodel2
+    - ls -R .
+    - cat setup.cfg
+    - cat dev-requirements.txt
+    - whoami
+    - apt-get update
+    - apt-get install -y python3-venv
+    - pip3 install -U setuptools_scm build twine setuptools
+    - python3 -m setuptools_scm
+    - python3 -m build
+    - twine check dist/*
+    - twine upload dist/*
+  variables:
+    TWINE_USERNAME: ${TWINE_USER}
+    TWINE_PASSWORD: ${TWINE_PASSWORD}
+  artifacts:
+    paths:
+      - dist/*.whl
+    reports:
+      dotenv: vars.env
+  rules:
+    - !reference [.override_gdcdictionary_version, rules]
+  dependencies:
+    - update_reqs_for_gdcdatamodel2
+    - execute_plaster
 
 push_datamodels_to_github:
   image: docker.osdc.io/ncigdc/python36-builder:1.4.0
@@ -95,4 +133,6 @@ push_datamodels_to_github:
   allow_failure: true   # failure when no changes of models
   rules:
     - !reference [.override_gdcdictionary_version, rules]
-  needs: ['update_reqs_for_gdcdatamodel2', 'execute_plaster']
+  dependencies:
+    - update_reqs_for_gdcdatamodel2
+    - execute_plaster