Default Environment Variables

Render automatically sets the values of certain environment variables for your service.

Unless otherwise noted, these environment variables are available at both build time and runtime.

Environment variable values are always strings.

In your application logic, perform any necessary conversions for variable values that represent other data types, such as "false" or "10000".

By runtime

All runtimes

Environment Variable	Value
`IS_PULL_REQUEST`	This value is `true` for pull request previews and `false` otherwise. Note that these are the string values `"true"` and `"false"`. Convert to booleans as needed.
`RENDER`	This value is always `true`. You can use this to detect whether your service is running on Render.
`RENDER_DISCOVERY_SERVICE`	The Render DNS name used to discover all running instances of a scaled service. Has the format `$RENDER_SERVICE_NAME-discovery`.
`RENDER_EXTERNAL_HOSTNAME`	For a web service or static site, this is the service’s `onrender.com` hostname (such as `myapp.onrender.com`). For other service types, this value is empty.
`RENDER_EXTERNAL_URL`	For a web service or static site, this is the service’s full `onrender.com` URL (such as `https://myapp.onrender.com`). For other service types, this value is empty.
`RENDER_GIT_BRANCH`	The Git branch for a service or deploy.
`RENDER_GIT_COMMIT`	The commit SHA for a service or deploy.
`RENDER_GIT_REPO_SLUG`	Has the format `$username/$reponame`.
`RENDER_INSTANCE_ID`	The unique identifier of the current service instance. Useful for scaled services with multiple instances.
`RENDER_SERVICE_ID`	The service’s unique identifier. Used in the Render API.
`RENDER_SERVICE_NAME`	A unique, human-readable identifier for a service.
`RENDER_SERVICE_TYPE`	The current service’s type. One of `web`, `pserv`, `cron`, `worker`, `static`.

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` (runtime only)
`NODE_MODULES_CACHE`	`true`

Python 3

Environment Variable	Value
`CI`	`true` (build time only)
`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` (runtime only)
`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

Environment Variable	Value
`PORT`	For web services, specify the port that your HTTP server binds to. The default port is `10000`.

PORT

For web services, specify the port that your HTTP server binds to.

The default port is 10000.

Node.js

Environment Variable	Value
`SKIP_INSTALL_DEPS`	Set this to `true` to skip running `yarn`/`npm install` during build.
`NODE_VERSION`	See Setting Your Node.js Version.

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.