Environment variables

Runtime environment variables

The Modal runtime sets several environment variables during initialization. The keys for these environment variables are reserved and cannot be overridden by your function configuration.

The following variables provide information about the function runtime environment:

  • MODAL_CLOUD_PROVIDER — Modal executes functions across a number of cloud providers (AWS, GCP, OCI). This variable specifies which cloud provider the Modal function is running within.
  • MODAL_ENVIRONMENT — The name of the Modal Environment the function is running within.
  • MODAL_IMAGE_ID — The ID of the modal.Image used by the Modal Function.
  • MODAL_REGION — This will correspond to a geographic area identifier from the cloud provider associated with the function (see above). For AWS, the identifier is a “region”. For GCP it is a “zone”, and for OCI it is an “availability domain”. Example values are ‘us-east-1’ (AWS), ‘us-central1’ (GCP), ‘us-ashburn-1’ (OCI).
  • MODAL_TASK_ID — The ID of the container running the Modal Function.

Container image environment variables

Container image layers used by a Modal function’s modal.Image will set environment variables which will be present within your function’s runtime environment. For example, the debian_slim image sets the GPG_KEY variable.

To override image variables or set new ones, use the .env method provided by modal.Image.