Default Environment Variables

Render provides additional environment variables to services at runtime, as well as during builds and deploys.

By runtime

All runtimes

Environment Variable	Value
`IS_PULL_REQUEST`	Set to `true` for Pull Request Previews. `false` for everything else.
`RENDER_DISCOVERY_SERVICE`	The Render DNS name used to discover all instances in multi-instance services. Of the form `$RENDER_SERVICE_NAME-discovery`.
`RENDER_EXTERNAL_HOSTNAME`	The Render host for a web service or static site. Of the form `foobar.onrender.com`. Empty for all other service types.
`RENDER_EXTERNAL_URL`	The Render URL for a web service or static site; of the form `https://foobar.onrender.com`. Empty for all other service types.
`RENDER_GIT_BRANCH`	The Git branch for a service or deploy.
`RENDER_GIT_COMMIT`	The commit SHA for a service or deploy.
`RENDER_GIT_REPO_SLUG`	`$username/$reponame`
`RENDER_INSTANCE_ID`	A unique identifier for an instance. Useful for multi-instance services.
`RENDER_SERVICE_ID`	A unique identifier for a service. Used in the Render API.
`RENDER_SERVICE_NAME`	A unique, human-readable identifier for a service.
`RENDER_SERVICE_TYPE`	One of `web`, `pserv`, `cron`, `worker`, `static`.
`RENDER`	Always set to `true`.

Other environment variables beginning with RENDER_ may be included in your build and runtime environments. However, variables not listed above are strictly for internal use and can change without warning.

Docker

Render does not provide additional environment variables on top of what’s listed under All runtimes.

Elixir

Environment Variable	Value
`MIX_ENV`	`prod`
`RELEASE_DISTRIBUTION`	`name`

Go

Environment Variable	Value
`GO111MODULE`	`on`
`GOPATH`	`/opt/render/project/go`

Node

Environment Variable	Value
`NODE_ENV`	`production` at runtime
`NODE_MODULES_CACHE`	`true`

Python 3

Environment Variable	Value
`CI`	`true` at buildtime
`FORWARDED_ALLOW_IPS`	`*`
`GUNICORN_CMD_ARGS`	`--preload --access-logfile - --bind=0.0.0.0:10000`
`PIPENV_YES`	`true`
`PYTHON_VERSION`	`3.7.10`
`VENV_ROOT`	`/opt/render/project/src/.venv`

Ruby

Environment Variable	Value
`BUNDLE_APP_CONFIG`	`/opt/render/project/.gems`
`BUNDLE_BIN`	`/opt/render/project/.gems/bin`
`BUNDLE_DEPLOYMENT`	`true`
`BUNDLE_PATH`	`/opt/render/project/.gems`
`GEM_PATH`	`/opt/render/project/.gems`
`MALLOC_ARENA_MAX`	`2`
`PASSENGER_ENGINE`	`builtin`
`PASSENGER_ENVIRONMENT`	`production`
`PASSENGER_PORT`	`10000`
`PIDFILE`	`/tmp/puma-server.pid`
`RAILS_ENV`	`production`
`RAILS_SERVE_STATIC_FILES`	`true`
`RAILS_LOG_TO_STDOUT`	`true`

Rust

Environment Variable	Value
`CARGO_HOME`	`opt/render/project/.cargo`
`ROCKET_ENV`	`prod`
`ROCKET_PORT`	`10000` at runtime
`RUSTUP_HOME`	`/opt/render/project/.rustup`

Optional environment variables

You can set these environment variables to modify the default behavior for your services.

All runtimes

Environment Variable	Value
`PORT`	For web services, specify your HTTP server’s port. The default port is `10000`.

Node.js

Environment Variable	Value
`SKIP_INSTALL_DEPS`	Users can set this to `true` to skip running yarn/npm install during build.
`NODE_VERSION`	See Specifying a Node Version for more options.

Setting environment variables

Render supports environment variables, configuration files, and secrets and lets you manage them at different levels of granularity to simplify your deployment processes.

See Environment Variables and Secrets.