> For the complete documentation index, see [llms.txt](https://ark-defai.gitbook.io/ark/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ark-defai.gitbook.io/ark/3.-the-three-layered-structure-of-ark-defai/layer-3-or-modeling-application-layer-the-protocols-senses-and-external-actions.md).

# Layer 3 | Modeling Application Layer: The Protocol's Senses and External Actions

If ARK is a city, then ARKLand is its streets and squares.

This is not just a showcase for governance, but also a laboratory for AI model implementation.

* Citizens can experience AI-driven model applications in ARKLand, such as financial assistants, risk management advisors, educational AI, and health recommendations.
* Each model serves as both a tool and a governance participant, adjusting parameters based on user feedback and entering the governance layer to contribute to public resource allocation recommendations.
* Citizen identity (NFT) functions not only as an entry ticket but also as an authorization certificate when interacting with models.