> For the complete documentation index, see [llms.txt](https://source-code-systems.gitbook.io/better-bank/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://source-code-systems.gitbook.io/better-bank/protocol-mechanics/admin-access/aave-v3-code.md).

# Aave v3 Code

Our **Lending and Borrowing is** a fork of **Aave V3 code**, that they graciously allow anyone to use. **These contracts**, once deployed, **cannot be upgraded**, so we are **completely unable to access anything** that **they didn’t mean** for admins **to access**. We will **describe the things we can change** that are important **for BetterBank**, but a full list can be found here in [Aave’s documentation](https://aave.com/docs/developers/smart-contracts/acl-manager).

**Lending pool contracts**

The BetterBank team **cannot ever access any deposited tokens that can serve as collateral** or are borrowable. There is a rescue token option, but that option **only works for delisted tokens** accidentally sent to the contract. This means that **if you lose access to or suffer from exploitation that compromises the security of**  the wallet with which you have deployed collateral, **we cannot help you**. **This** inability however **means absolute safety.** There is simply **no possibility for anyone but you to withdraw** your assets, ever.

**Setting interest rates and lending spreads**

The **BetterBank** team **can change the interest rates** and also the spread between paid interest and received interest. **We don’t plan on changing these,** though and instead we plan on sticking by the settings we explain elsewhere in the docs. **But should we need** to change something, **we can**.

**Borrow caps & collateral caps**

The **BetterBank** team **can set a maximum** to either of these values, **per token**. We use this **in the background** as an extra layer **for safety**, in such a way that normal use should not ever reach the caps. **We can** use this feature also if we ever want **to delist a token**, as we can phase out a token by lowering these values over time.

**Listing, delisting, and isolating**

Obviously **we can list new tokens and delist them too**. And **we can “isolate”** markets, meaning that certain collateral can only be used to borrow certain assets.