Azure Functions

Azure Functions is the Azure-native serverless compute platform — tightly integrated with Azure Storage queues, Service Bus, Event Hubs, Cosmos DB, and 20+ other trigger sources. For agents: HTTP-triggered functions for synchronous tool calls, queue-triggered for async task processing, timer-triggered for scheduled jobs, and Durable Functions for stateful multi-step orchestration. Managed identity eliminates credential management for Azure resource access. Confidence is docs-derived.

Azure SDK (azure-functions, azure-mgmt-web). Function definition (Python): @app.function_name(name="HttpExample") @app.route(route="HttpExample") def main(req: func.HttpRequest) -> func.HttpResponse. Durable Functions: @orchestrator decorator for stateful workflows. Management API: azure-mgmt-web for function app management. Azure CLI: az functionapp deploy, az functionapp list. REST API for function invocation: POST {function-url}/api/{function-name}?code={key}.

Azure AD managed identity (preferred): no credential management for function apps running on Azure. Function-level keys (default, master, anonymous). Host keys for app-level access. Azure AD token for secured HTTP triggers. HTTPS enforced. Managed identity grants access to other Azure resources via Azure RBAC.

FunctionInvocationException for runtime errors. Timeout: Consumption plan max 5 minutes (Premium/Dedicated: configurable to 60+ minutes). Scale: Consumption plan scales to 200 concurrent instances max. Cold start on scale-from-zero (typically 1–5 seconds for .NET; higher for Python). Durable Functions: fault-tolerant via replay journal. Azure Functions SLA: 99.95% on Premium/Dedicated; best-effort on Consumption.

docs.microsoft.com/azure/azure-functions is Microsoft Learn documentation — developer guides for all runtimes, trigger/binding reference, Durable Functions guide, and deployment options. Getting started: Azure Portal or VS Code Azure Functions extension — first function in under 5 minutes. Free tier: 1M executions + 400K GB-seconds/month. Community via Microsoft Q&A and Azure Functions GitHub.