ML Metadata (MLMD) is a library for recording and retrieving metadata associated with ML developer and data scientist workflows.

NOTE: ML Metadata may be backwards incompatible before version 1.0.

For more background on MLMD and instructions on using it, see the getting started guide

The recommended way to install ML Metadata is to use the PyPI package:

pip install ml-metadata

Then import the relevant packages:

from ml_metadata import metadata_store
from ml_metadata.proto import metadata_store_pb2

ML Metadata (MLMD) also hosts nightly packages at https://pypi-nightly.tensorflow.org on Google Cloud. To install the latest nightly package, please use the following command:

pip install --extra-index-url https://pypi-nightly.tensorflow.org/simple ml-metadata

This is the recommended way to build ML Metadata under Linux, and is continuously tested at Google.

Please first install docker and docker-compose by following the directions: docker; docker-compose.

Then, run the following at the project root:

DOCKER_SERVICE=manylinux-python${PY_VERSION}
sudo docker compose build ${DOCKER_SERVICE}
sudo docker compose run ${DOCKER_SERVICE}

where PY_VERSION is one of {39, 310, 311}.

A wheel will be produced under dist/, and installed as follows:

pip install dist/*.whl

To compile and use ML Metadata, you need to set up some prerequisites.

If Bazel is not installed on your system, install it now by following these directions.

If cmake is not installed on your system, install it now by following these directions.

git clone https://github.com/google/ml-metadata
cd ml-metadata

Note that these instructions will install the latest master branch of ML Metadata. If you want to install a specific branch (such as a release branch), pass -b <branchname> to the git clone command.

ML Metadata uses Bazel to build the pip package from source:

python setup.py bdist_wheel

You can find the generated .whl file in the dist subdirectory.

pip install dist/*.whl

ML Metadata uses Bazel to build the c++ binary from source:

bazel build -c opt --define grpc_no_ares=true  //ml_metadata/metadata_store:metadata_store_server

MLMD is built and tested on the following 64-bit operating systems:

• macOS 10.14.6 (Mojave) or later.
• Ubuntu 20.04 or later.
• [DEPRECATED] Windows 10 or later. For a Windows-compatible library, please refer to MLMD 1.14.0 or earlier versions.

Before releasing, you need to set up the PyPI environment and token once:

Step 1: Create PyPI environment

Create a new environment named pypi in the GitHub repository:

• Go to https://github.com/google/ml-metadata/settings/environments/new
• Name it pypi
• Click "Configure environment"

Step 2: Add PYPI_TOKEN secret

Add your PyPI token to the pypi environment:

• In the pypi environment settings, scroll to "Environment secrets"
• Click "Add secret"
• Name: PYPI_TOKEN (use this exact name)
• Value: Your PyPI API token
• Click "Add secret"

Step 3: Commit and push your release branch

Ensure your release branch has the correct version set in ml_metadata/version.py, then:

git add ml_metadata/version.py
git commit -m "Prepare release vX.Y.Z"
git push origin your-release-branch

This method allows you to manually trigger a release from any branch without creating a GitHub release.

Steps (after completing setup above):

1. Navigate to the GitHub Actions page: https://github.com/google/ml-metadata/actions
2. Find and select the Build ml-metadata with Conda workflow: https://github.com/google/ml-metadata/actions/workflows/conda-build.yml
3. Click the "Run workflow" dropdown button.
4. Select your release branch from the dropdown menu.
5. Click "Run workflow".

The workflow will build wheels for all supported Python versions and automatically upload them to PyPI if the token is configured correctly.

This method creates a formal GitHub release with a tag, which automatically triggers the build and upload workflow.

Steps (after completing setup above):

1. Go to the Releases tab: https://github.com/google/ml-metadata/releases
2. Click the Draft new release button (you'll be redirected to https://github.com/google/ml-metadata/releases/new)
3. Click the Select tag button and create a new tag for your release (e.g., v1.18.0)
4. Click the Target dropdown and select your release branch
5. Fill in the Release title and Release notes sections
6. Choose the release type:
   • Check Set as a pre-release if this is a beta/test release
   • Leave unchecked for Set as the latest release for stable releases
7. Click the Publish release button
8. Verify the workflow is running by going to the Actions tab: https://github.com/google/ml-metadata/actions/workflows/conda-build.yml

The Build ml-metadata with Conda workflow will automatically trigger and build/upload wheels to PyPI if the token is configured correctly.