> For the complete documentation index, see [llms.txt](https://docs.aisuru.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aisuru.com/en/advanced-features/integrations/functions/advanced-functions.md).

# Advanced functions

AIsuru's advanced functions let you create custom integrations between your Agent and external services through webhooks. This feature (also known as function calling) lets you go beyond built-in functions and build solutions tailored to your specific needs.

### What are advanced functions?

Unlike built-in functions, which provide pre-configured tools, advanced functions let you:

* Create custom integrations with any external service;
* Automate complex processes specific to your use case;
* Retrieve real-time data from your own proprietary sources;
* Have your Agent perform specific actions.

### How they work

When a user asks a question:

1. The generative AI decides whether and which function to call, based on the instructions and the function's description;
2. The function sends a request to the configured webhook;
3. The webhook processes the request and returns a response;
4. The language model analyzes the response and generates a natural reply for the user.

The real power of advanced functions lies in their flexibility: the webhook can return data in any format (JSON, markdown, text, HTML), and the language model will process it to craft an appropriate response.

### When to use advanced functions

Advanced functions are ideal when you need to:

* Integrate the Agent with proprietary systems;
* Create complex, custom automations;
* Retrieve data from sources not accessible through built-in functions;
* Execute actions specific to your use case.

In the next sections we'll look in detail at how to [configure advanced functions](/en/advanced-features/integrations/functions/advanced-functions/how-to-configure-a-custom-function.md), [best practices](/en/advanced-features/integrations/functions/advanced-functions/best-practices.md) for using them, and how to handle [common issues](/en/advanced-features/integrations/functions/advanced-functions/common-issues-with-advanced-functions.md).


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# Agent Instructions
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## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.aisuru.com/en/advanced-features/integrations/functions/advanced-functions.md?ask=<question>&goal=<endgoal>
```

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Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.