Skip to content

Environment Variables

This reference lists key environment and app settings for Azure Functions Node.js v4 applications.

Topic/Command Groups

flowchart LR
    A[Settings] --> B[Runtime]
    A --> C[Node worker]
    A --> D[Observability]
Variable Purpose Typical Value
FUNCTIONS_WORKER_RUNTIME Select language worker node
FUNCTIONS_EXTENSION_VERSION Runtime major line ~4
WEBSITE_NODE_DEFAULT_VERSION Node version on Windows workers only ~20
siteConfig.linuxFxVersion Node runtime stack on Linux workers Node|20
languageWorkers__node__arguments Node process flags --max-old-space-size=4096
AzureWebJobsStorage Host storage connection Connection string or identity settings
APPLICATIONINSIGHTS_CONNECTION_STRING Telemetry ingestion target <connection-string>

Apply settings

az functionapp config appsettings set --name $APP_NAME --resource-group $RG --settings "FUNCTIONS_WORKER_RUNTIME=node" "FUNCTIONS_EXTENSION_VERSION=~4" "WEBSITE_NODE_DEFAULT_VERSION=~20" "languageWorkers__node__arguments=--max-old-space-size=4096"
az functionapp config appsettings set --name $APP_NAME --resource-group $RG --settings "FUNCTIONS_WORKER_RUNTIME=node" "FUNCTIONS_EXTENSION_VERSION=~4" "languageWorkers__node__arguments=--max-old-space-size=4096"
az functionapp config set --name $APP_NAME --resource-group $RG --linux-fx-version "Node|20"
  • Windows apps use WEBSITE_NODE_DEFAULT_VERSION.
  • Linux apps use siteConfig.linuxFxVersion through az functionapp config set --linux-fx-version "Node|20".

Usage Notes

  • Keep local values in local.settings.json and exclude from source control.
  • Prefer identity-based connections when available.
  • Use separate settings per environment (dev, test, prod).

See Also

Sources