> For the complete documentation index, see [llms.txt](https://qualitax.gitbook.io/interop/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://qualitax.gitbook.io/interop/requirements/foundational-layer/function-call-sub-layer.md).

# Function call sub-layer

**Focus**: Invocation and execution of functions across blockchains.

**Objective**: Allow execution of business logic across chains. Facilitate seamless and compliant execution of functions or operations across different blockchains, ensuring that a function initiated on one blockchain can trigger and execute corresponding logic on another, all while adhering to regulatory requirements.

**Description**: Provides standards and protocols for calling functions like smart contracts across interconnected blockchains and synchronizing state changes. This layer is pivotal to achieving meaningful crosschain operations. It ensures that functions, especially those defined in smart contracts, can be executed not just within their native blockchain but can also invoke or be invoked by functions on other blockchains. In the context of regulated settings, it's essential that these crosschain function calls also adhere to the relevant regulatory and compliance standards. This might involve verifying the legitimacy of the calling function, ensuring data privacy and security, and ensuring that the operations do not violate any regulatory mandates.

**Layer owner**: Crosschain protocol developers, smart contract developers.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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://qualitax.gitbook.io/interop/requirements/foundational-layer/function-call-sub-layer.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

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.