/azure-functions

name: azure-functions
description: Expert knowledge for Azure Functions development including troubleshooting, best practices, decision making, architecture & design patterns, limits & quotas, security, configuration, integrations & coding patterns, and deployment. Use when building trigger/binding workflows, Durable orchestrations, VNet/private endpoint apps, CI/CD deployments, or Flex/Fn plans, and other Azure Functions related development tasks. Not for Azure App Service (use azure-app-service), Azure Logic Apps (use azure-logic-apps), Azure Container Apps (use azure-container-apps), Azure Kubernetes Service (AKS) (use azure-kubernetes-service).
compatibility: Requires network access. Uses mcp_microsoftdocs:microsoft_docs_fetch or fetch_webpage to retrieve documentation.
metadata:
  generated_at: "2026-09-13"
  generator: "docs2skills/1.0.0"

Azure Functions Skill

This skill provides expert guidance for Azure Functions. Covers troubleshooting, best practices, decision making, architecture & design patterns, limits & quotas, security, configuration, integrations & coding patterns, and deployment. It combines local quick-reference content with remote documentation fetching capabilities.

How to Use This Skill

> **IMPORTANT for Agent**: Use the **Category Index** below to locate relevant sections. For categories with line ranges (e.g., `L35-L120`), use `read_file` with the specified lines. For categories with file links (e.g., `[security.md](security.md)`), use `read_file` on the linked reference file

> **IMPORTANT for Agent**: If `metadata.generated_at` is more than 3 months old, suggest the user pull the latest version from the repository. If `mcp_microsoftdocs` tools are not available, suggest the user install it: [Installation Guide](https://github.com/MicrosoftDocs/mcp/blob/main/README.md)

This skill requires **network access** to fetch documentation content:

• **Preferred**: Use `mcp_microsoftdocs:microsoft_docs_fetch` with query string `from=learn-agent-skill`. Returns Markdown.
• **Fallback**: Use `fetch_webpage` with query string `from=learn-agent-skill&accept=text/markdown`. Returns Markdown.

Category Index

| Category | Lines | Description | |----------|-------|-------------| | Troubleshooting | L37-L73 | Diagnosing and fixing Azure Functions errors (AZFD/AZFW codes), storage/config issues, extension/version problems, runtime/networking failures, and language-specific (Node.js/Python) troubleshooting. | | Best Practices | L74-L91 | Design, coding, error-handling, performance, scaling, and reliability best practices for Azure Functions across .NET, Node.js, Java, and Python, including DI, idempotency, HttpClient, and memory use. | | Decision Making | L92-L112 | Guidance on choosing Functions hosting/runtime options, cost planning, and step-by-step migrations (plans, .NET models, extensions, AWS Lambda, Cosmos DB, Service Bus) across versions. | | Architecture & Design Patterns | L113-L117 | Patterns for building dynamic, workflow-based skills with Azure Functions, including orchestration, state management, and integrating Functions into larger app architectures. | | Limits & Quotas | L118-L125 | Scaling limits, concurrency controls, and configuration for event-driven, Flex Consumption, and target-based scaling behavior in Azure Functions. | | Security | L126-L140 | Securing Azure Functions: encryption at rest, storage and key protection, networking/VNet/private endpoints, private site access, managed identity for SQL, and App Service security features. | | Configuration | L141-L187 | Configuring Azure Functions behavior, bindings, triggers, networking, monitoring/telemetry, runtime versions, and local development tools for different languages and hosting plans. | | Integrations & Coding Patterns | L188-L291 | Using triggers, bindings, and worker extensions to connect Azure Functions to services (databases, messaging, AI/OpenAI, MCP, Dapr, SignalR, Web PubSub, APIs) and implement integration patterns. | | Deployment | L292-L321 | Deploying and hosting Azure Functions: provisioning infrastructure (Bicep/ARM/Terraform), CI/CD (GitHub Actions, Pipelines), containers/Kubernetes, slots, Flex/zone redundancy, and language‑specific deploy guides. |

Troubleshooting

| Topic | URL | |-------|-----| | Resolve AZFD0001 missing AzureWebJobsStorage setting | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0001 | | Fix AZFD0002 invalid AzureWebJobsStorage value | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0002 | | Troubleshoot AZFD0003 StorageException fetching diagnostics | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0003 | | Resolve AZFD0004 Azure Functions host ID collision | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0004 | | Fix AZFD0005 external startup exception in Functions | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0005 | | Handle AZFD0006 expiring SAS token warnings | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0006 | | Resolve AZFD0007 too many secrets backups | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0007 | | Fix AZFD0008 archive-tier Blob secrets repository | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0008 | | Resolve AZFD0009 unable to parse host.json | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0009 | | Fix AZFD0010 TZ/WEBSITE_TIME_ZONE on Linux Consumption | https://learn.microsoft.com/en-us/azure/azure-functions/errors-diagnostics/diagnostic-events/azfd0010 | | Resolve AZFD0011 missing FUNCTIONS_WORKER_RUNTIME | https://learn.microsoft.com/en-us/azure/azure-functions/errors-dia