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IntroductionCustom container images Defining ImagesPrivate registriesFast pull from registryGPUs and other resources GPU accelerationUsing CUDA on ModalReserving CPU and memoryScaling out Scaling outDicts and queuesJob processingConcurrent inputs on a single container (beta)Dynamic batching (beta)Scheduling and cron jobsDeployment Apps, Stubs, and entrypointsManaging deploymentsInvoking deployed functionsContinuous deploymentSecrets and environment variables SecretsEnvironment variablesWeb endpoints Web endpointsStreaming endpointsWeb endpoint URLsRequest timeoutsWebhook tokens (beta)Networking Tunnels (beta)Proxies (beta)Data sharing and storage Passing local dataVolumesMounting local files and directoriesStoring model weightsDataset ingestionCloud bucket mountsNetwork file systems (superseded)Sandboxes SandboxesRunning commandsNetworking and securityFile accessSnapshotsPerformance Cold start performanceMemory Snapshot (beta)Geographic latencyReliability and robustness Failures and retriesPreemptionTimeoutsTroubleshootingSecurity and privacyIntegrations Using OIDC to authenticate with external servicesConnecting Modal to your Vercel accountConnecting Modal to your Datadog accountConnecting Modal to your OpenTelemetry providerOkta SSOSlack notifications (beta)Other topics File and project structureDeveloping and debuggingModal user account setupWorkspacesEnvironmentsJupyter notebooksAsynchronous API usageGlobal variablesRegion selectionContainer lifecycle hooksParameterized functionsS3 Gateway endpoints

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’s 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_IS_REMOTE - Set to ‘1’ to indicate that the function code is running in a remote container.
  • 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.
  • MODAL_IDENTITY_TOKEN — An OIDC token encoding the identity of the Modal Function.

Container image environment variables

The container image layers used by a Modal Function’s modal.Image may set environment variables. These variables 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.