Environment variables

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

READTHEDOCS

Whether the build is running inside Read the Docs.

Default:: True

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

READTHEDOCS_LANGUAGE

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

READTHEDOCS_VERSION: 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.

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

READTHEDOCS_VERSION_TYPE

The type of the version being built.

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

READTHEDOCS_VIRTUALENV_PATH

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

READTHEDOCS_CANONICAL_URL

Canonical base URL for the version that is built. If the project has configured a custom domain (e.g. docs.example.com) it will be used in the resulting canonical URL. Otherwise, your project’s default subdomain will be used.

The path for the language and version is appended to the domain, so the final canonical base URLs can look like the following examples:

Example:: https://docs.example.com/en/latest/
Example:: https://docs.readthedocs.io/ja/stable/
Example:: https://example--17.org.readthedocs.build/fr/17/