> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/MicrosoftDocs/azure-ai-docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Azure Functions Tool

> Integrate agents with Azure Functions for serverless tool execution, enterprise system integration, and complex workflows.

# Azure Functions Tool

Azure Functions enables serverless compute for agent tools, providing enterprise integration capabilities with custom code execution.

## When to Use Azure Functions

Choose Azure Functions over function calling when you need:

* **Separation of concerns**: Isolate business logic from agent code
* **Centralized management**: Share tools across multiple agents
* **Security isolation**: Control agent and tool permissions separately
* **External dependencies**: Use non-Microsoft libraries or legacy systems
* **Complex operations**: Handle multi-step workflows
* **Async processing**: Execute long-running operations

## Integration Options

### Queue-Based Tools

Asynchronous processing via Azure Queue Storage:

```python theme={null}
from azure.ai.projects.models import AzureFunctionTool

function_tool = AzureFunctionTool(
    name="process_order",
    description="Process a customer order",
    input_binding={"storage_queue": "order-queue"},
    output_binding={"storage_queue": "order-results"}
)
```

**Best for**: Background processing, reliable message delivery, retry capabilities

### HTTP-Based Tools

Synchronous calls via HTTP triggers (use OpenAPI tool)

**Best for**: Real-time responses, immediate feedback

### MCP Server

Model Context Protocol for reusable tool catalogs

**Best for**: Industry standard, shared tools across agents

## Quick Start Template

<Steps>
  <Step title="Initialize Template">
    ```bash theme={null}
    azd init --template azure-functions-ai-services-agent-python
    ```
  </Step>

  <Step title="Provision Resources">
    ```bash theme={null}
    azd provision
    ```

    Creates: Function app, Foundry resources, Storage, Cosmos DB, AI Search
  </Step>

  <Step title="Deploy Code">
    ```bash theme={null}
    azd deploy
    ```
  </Step>
</Steps>

## Prerequisites

* Azure Functions Core Tools v4.x
* Deployed agent with Standard Setup (Basic not supported)
* Azure account with active subscription

See [Function Calling](/foundry/agents/tools/function-calling) for in-process functions.