@app.function_name(name="my_function") @app.route(route="api/endpoint", methods=["GET", "POST"]) def my_function(req: func.HttpRequest) -> func.HttpResponse: """HTTP trigger function with proper error handling.""" try: # Parse request data = req.get_json() if req.method == "POST" else dict(req.params)

    # Your logic here
    result = {"status": "success", "data": data}
    
    return func.HttpResponse(
        body=json.dumps(result),
        status_code=200,
        mimetype="application/json"
    )
except Exception as e:
    return func.HttpResponse(
        body=json.dumps({"error": str(e)}),
        status_code=500,
        mimetype="application/json"
    )


### MCP Tool Trigger

```python
@app.generic_trigger(
    arg_name="context",
    type="mcpToolTrigger",
    toolName="my_tool",
    description="What this tool does and when to use it",
    toolProperties='[{"propertyName": "input", "propertyType": "string", "description": "The input parameter"}]'
)
def my_tool(context) -> str:
    """MCP tool function."""
    content = json.loads(context)
    input_value = content["arguments"].get("input", "")
    return json.dumps({"result": input_value})

Configuration Files

host.json (Runtime Config)

{
  "version": "2.0",
  "extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle",
    "version": "[4.*, 5.0.0)"
  },
  "extensions": {
    "mcp": {
      "enabled": true
    }
  }
}

local.settings.json (Local Development)

{
  "IsEncrypted": false,
  "Values": {
    "FUNCTIONS_WORKER_RUNTIME": "python",
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "AzureWebJobsFeatureFlags": "EnableWorkerIndexing"
  }
}

Local Development Commands

# Start Azurite storage emulator (required)
azurite --silent --location /tmp/azurite

# Start the function app locally
cd src/function_app_directory
func start

# Install Azure Functions Core Tools (macOS)
brew tap azure/functions
brew install azure-functions-core-tools@4

Deployment with Azure Developer CLI

# Initialize project from template
azd init --template <template-name> -e <environment-name>

# Deploy to Azure
azd up

# Get function keys
az functionapp keys list --resource-group <rg> --name <app-name>

Common Issues and Solutions

Issue	Solution
`AzureWebJobsStorage` error	Start Azurite: `azurite --silent`
Functions not discovered	Ensure `host.json` has correct extension bundle
MCP tools not showing	Check `mcp.enabled: true` in host.json extensions
401 Unauthorized	Include `x-functions-key` header for FUNCTION auth level

Best Practices

Always use type hints for better IDE support
Log important operations with logging.info() and logging.error()
Return JSON responses with appropriate status codes
Use FUNCTION auth level for production (not ANONYMOUS)
Test locally with func start before deploying

azure-functions

Azure Functions Development Skill

Overview

Key Patterns

HTTP Trigger Function