docs/content/actions/reference/environment-variables.md

title, intro, product, redirect_from, versions

title	intro	product	redirect_from	versions
Environment variables	{% data variables.product.prodname_dotcom %} sets default environment variables for each {% data variables.product.prodname_actions %} workflow run. You can also set custom environment variables in your workflow file.	{% data reusables.gated-features.actions %}	/github/automating-your-workflow-with-github-actions/using-environment-variables /actions/automating-your-workflow-with-github-actions/using-environment-variables /actions/configuring-and-managing-workflows/using-environment-variables	free-pro-team enterprise-server * >=2.22

{% data reusables.actions.enterprise-beta %} {% data reusables.actions.enterprise-github-hosted-runners %}

About environment variables

{% data variables.product.prodname_dotcom %} sets default environment variables that are available to every step in a workflow run. Environment variables are case-sensitive. Commands run in actions or steps can create, read, and modify environment variables.

To set custom environment variables, you need to specify the variables in the workflow file. You can define environment variables for a step, job, or entire workflow using the jobs.<job_id>.steps[*].env, jobs.<job_id>.env, and env keywords. For more information, see "Workflow syntax for {% data variables.product.prodname_dotcom %}."

steps:
  - name: Hello world
    run: echo Hello world $FIRST_NAME $middle_name $Last_Name!
    env:
      FIRST_NAME: Mona
      middle_name: The
      Last_Name: Octocat

You can also use the {% if currentVersion == "free-pro-team@latest" or currentVersion ver_gt "enterprise-server@2.22" %}GITHUB_ENV environment file{% else %} set-env workflow command{% endif %} to set an environment variable that the following steps in a workflow can use. The {% if currentVersion == "free-pro-team@latest" or currentVersion ver_gt "enterprise-server@2.22" %}environment file{% else %} set-env command{% endif %} can be used directly by an action or as a shell command in a workflow file using the run keyword. For more information, see "Workflow commands for {% data variables.product.prodname_actions %}."

Default environment variables

We strongly recommend that actions use environment variables to access the filesystem rather than using hardcoded file paths. {% data variables.product.prodname_dotcom %} sets environment variables for actions to use in all runner environments.

Environment variable	Description
CI	Always set to true.
GITHUB_WORKFLOW	The name of the workflow.
GITHUB_RUN_ID	{% data reusables.github-actions.run_id_description %}
GITHUB_RUN_NUMBER	{% data reusables.github-actions.run_number_description %}
GITHUB_ACTION	The unique identifier (id) of the action.
GITHUB_ACTIONS	Always set to true when {% data variables.product.prodname_actions %} is running the workflow. You can use this variable to differentiate when tests are being run locally or by {% data variables.product.prodname_actions %}.
GITHUB_ACTOR	The name of the person or app that initiated the workflow. For example, octocat.
GITHUB_REPOSITORY	The owner and repository name. For example, octocat/Hello-World.
GITHUB_EVENT_NAME	The name of the webhook event that triggered the workflow.
GITHUB_EVENT_PATH	The path of the file with the complete webhook event payload. For example, /github/workflow/event.json.
GITHUB_WORKSPACE	The {% data variables.product.prodname_dotcom %} workspace directory path. The workspace directory is a copy of your repository if your workflow uses the actions/checkout action. If you don't use the actions/checkout action, the directory will be empty. For example, /home/runner/work/my-repo-name/my-repo-name.
GITHUB_SHA	The commit SHA that triggered the workflow. For example, ffac537e6cbbf934b08745a378932722df287a53.
GITHUB_REF	The branch or tag ref that triggered the workflow. For example, refs/heads/feature-branch-1. If neither a branch or tag is available for the event type, the variable will not exist.
GITHUB_HEAD_REF	Only set for pull request events. The name of the head branch.
GITHUB_BASE_REF	Only set for pull request events. The name of the base branch.
GITHUB_SERVER_URL	Returns the URL of the {% data variables.product.product_name %} server. For example: https://{% data variables.product.product_url %}.
GITHUB_API_URL	Returns the API URL. For example: {% data variables.product.api_url_code %}.
GITHUB_GRAPHQL_URL	Returns the GraphQL API URL. For example: {% data variables.product.graphql_url_code %}.

{% tip %}

Note: If you need to use a workflow run's URL from within a job, you can combine these environment variables: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID

{% endtip %}

Determining when to use default environment variables or contexts

{% data reusables.github-actions.using-context-or-environment-variables %}

Naming conventions for environment variables

{% note %}

Note: {% data variables.product.prodname_dotcom %} reserves the GITHUB_ environment variable prefix for internal use by {% data variables.product.prodname_dotcom %}. Setting an environment variable or secret with the GITHUB_ prefix will result in an error.

{% endnote %}

Any new environment variables you set that point to a location on the filesystem should have a _PATH suffix. The HOME and GITHUB_WORKSPACE default variables are exceptions to this convention because the words "home" and "workspace" already imply a location.