Global Rules

User Confirmation Required

Always use ask_user before:

• Selecting Azure subscription
• Selecting Azure region/location
• Deploying infrastructure
• Making breaking changes to existing code

Best Practices

• Always use mcp_azure_mcp_get_azure_bestpractices tool before generating Azure code
• Prefer managed identity over connection strings
• Always use the latest supported language runtime — check supported languages (opens in a new tab) for the newest GA version. Never default to older versions
• Always prefer bindings over SDKs — use input.storageBlob(), output.storageBlob(), app.storageQueue(), etc. instead of BlobServiceClient, QueueClient, or other SDK clients. Only use SDK when no binding exists for the service
• Follow Azure naming conventions
• Use Flex Consumption hosting plan for new Functions

Identity-First Authentication (Zero API Keys)

Enterprise subscriptions commonly enforce policies that block local auth. Always design for identity-based access from the start.

• Storage accounts: Set allowSharedKeyAccess: false. Use identity-based connections with AzureWebJobsStorage__credential, __clientId, and service-specific URIs (__blobServiceUri, __queueServiceUri, etc.)
• Cognitive Services: Set disableLocalAuth: true. Use UAMI + RBAC role (e.g., Cognitive Services User) instead of API keys
• Application Insights: Set disableLocalAuth: true. Use APPLICATIONINSIGHTS_AUTHENTICATION_STRING with ClientId=<uamiClientId>;Authorization=AAD
• DefaultAzureCredential with UAMI: When using User Assigned Managed Identity, always pass managedIdentityClientId explicitly:

  javascriptCopy

  const credential = new DefaultAzureCredential({
    managedIdentityClientId: process.env.AZURE_CLIENT_ID
  });

  Without this, DefaultAzureCredential tries SystemAssigned first and fails. Add AZURE_CLIENT_ID as an app setting mapped to the UAMI client ID.

Flex Consumption Specifics

• Always-ready for non-HTTP triggers: Blob trigger groups on Flex Consumption require alwaysReady: [{ name: "blob", instanceCount: 1 }] to bootstrap the trigger listener. Without it, the trigger group never starts and Event Grid subscriptions are never auto-created (chicken-and-egg problem)
• Blob trigger with EventGrid source requires queue endpoint: The blob extension internally uses queues for poison-message tracking. Must include AzureWebJobsStorage__queueServiceUri even when using blob trigger (not queue trigger)
• Event Grid subscriptions via Bicep/ARM only: Do NOT create Event Grid event subscriptions via CLI — webhook validation fails on Flex Consumption with “response code Unknown”. Deploy as Bicep resources using listKeys() to resolve the blobs_extension system key at deployment time
• azd init on non-empty directories: azd init --template refuses non-empty directories. Use temp directory approach: init in temp, copy template infrastructure files back