Get started
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Get Started with CML on GitHub

Here, we'll walk through a tutorial to start using CML. For simplicity, we'll show the demo in GitHub Actions, but instructions are pretty similar for all the supported CI systems.

  1. Fork our example project repository.

    fork cml project

The following steps can all be done in the GitHub browser interface. However, to follow along the commands, we recommend cloning your fork to your local workstation:

$ git clone<your-username>/example_cml
$ cd example_cml
  1. To create a CML workflow, copy the following into a new file at .github/workflows/cml.yaml:

    name: CML
    on: [push]
        runs-on: ubuntu-latest
        container: docker://
          - uses: actions/checkout@v3
              ref: ${{ github.event.pull_request.head.sha }}
          - name: Train model
              REPO_TOKEN: ${{ secrets.GITHUB_TOKEN }}
            run: |
              pip install -r requirements.txt
              cat metrics.txt >>
              echo '![](./plot.png)' >>
              cml comment create --publish
  2. In your text editor, open and modify line 15 to depth = 5.

  3. Commit and push the changes:

    $ git checkout -b experiment
    $ git add . && git commit -m "modify forest depth"
    $ git push origin experiment
  4. In GitHub, create a Pull Request to compare the experiment branch to master.

    Ensure the target is your fork (under your username).

    make pr

    Shortly, you should see a comment appear in the Pull Request with your CML report. This is a result of the cml comment create command in your workflow.

    cml first report

This is the gist of the CML workflow: when you push changes to your GitHub repository, the workflow in your .github/workflows/cml.yaml file gets run and a report generated.

CML commands let you display relevant results from the workflow, like model performance metrics and vizualizations, in GitHub checks and comments. What kind of workflow you want to run, and want to put in your CML report, is up to you.

Final Solution

An example of what your repository should look like now can be found at iterative/cml_base_case.

Setup Action

In the above example, we got the CML commands thanks to our Docker container. But there's another way for GitHub Actions users to get CML: the setup-cml Action!

The iterative/setup-cml action is a JavaScript workflow that provides CML commands in your GitHub Actions workflow. The action allows users to install CML without using the CML Docker container.

This action gives you:

  • Commands like cml comment create for publishing data visualization and metrics from your CI workflow as comments in a pull request.
  • cml runner, a command that enables workflows to provision cloud and on-premise computing resources for training models
  • The freedom 🦅 to mix and match CML with your favorite data science tools and environments

Note that CML does not include DVC and its dependencies — for that, you want the Setup DVC Action.


This action has been tested on ubuntu-latest and macos-latest.

Basic usage:

  - uses: iterative/setup-cml@v1

A specific version can be pinned to your workflow.

  - uses: iterative/setup-cml@v1
      version: '1.0.1'


The following inputs are supported.

  • version - (optional) The version of CML to install. The default value of latest will install the latest version of CML.


Setup CML has no outputs.

A complete workflow

Assume that we have a machine learning script,, that outputs an image plot.png. A potential workflow will look like this:

  - uses: iterative/setup-cml@v1
  - uses: actions/checkout@v3
      ref: ${{ github.event.pull_request.head.sha }}
  - env:
      REPO_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    run: |
      # train will generate plot.png

      echo "# My first CML report" >>
      echo '![](./plot.png "Confusion Matrix")' >>
      cml comment create --publish

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