# Environment variables

All build processes have the following environment variables automatically defined and available for each build step:

Whether the build is running inside Read the Docs.

Default:

True

The slug of the project being built. For example, my-example-project.

The locale name, or the identifier for the locale, for the project being built. This value comes from the project’s configured language.

Examples:

en, it, de_AT, es, pt_BR

The slug of the version being built, such as latest, stable, or a branch name like feature-1234. For pull request builds, the value will be the pull request number.

The verbose name of the version being built, such as latest, stable, or a branch name like feature/1234.

The type of the version being built.

Values:

branch, tag, external (for pull request builds), or unknown

Path for the virtualenv that was created for this build. Only exists for builds using Virtualenv and not Conda.

Example:

/home/docs/checkouts/readthedocs.org/user_builds/project/envs/version