# afiUSD Vault

AFI POR USD Vaults are the foundational layer for generating and distributing yield across the protocol. Each vault adheres to the ERC-4626 standard and includes advanced features such as yield vesting, withdrawal cooldowns, and global cross-chain coordination. These vaults form the asset layer backing AFI’s index products such as afiUSD ( POR-USD Vault )

### afiUSD Vault <a href="#afiusd-vault" id="afiusd-vault"></a>

The <kbd>afiUSD</kbd> Vault is the primary implementation of the AFI yield infrastructure on supported chains. It is a fully compliant ERC-4626 vault with protocol-specific enhancements.

#### Key Features - <a href="#key-features" id="key-features"></a>

* **ERC-4626 Compliance** - Implements the full ERC-4626 tokenized vault interface, allowing seamless interoperability with other DeFi protocols.
* **Withdrawal Cooldown** - Introduces a **72-hour cooldown period** post-withdrawal request to allow strategy unwinding and ensure liquidity availability.
* **Yield Vesting** - Yield generated by AFI is incorporated into the vault's exchange rate **gradually**, smoothing accrual and preventing front-running or deposit-timing arbitrage.
* **Fee Management -** Fee Management supports configurable deposit and withdrawal fees, programmable at the vault or strategy level. Currently, both fees are set to 0.
* **Virtual Asset Accounting** - Tracks total assets under management, including **vested and unvested yield**, to provide accurate NAV computation.

***

### Cross-Chain Yield Distribution <a href="#cross-chain-yield-distribution" id="cross-chain-yield-distribution"></a>

afiUSD will operate vaults across multiple chains - each independently collecting deposits and generating yield. However, yield distribution is coordinated globally to ensure fairness and consistency in `afiUSD` value across all deployments.

#### Objectives - <a href="#objectives" id="objectives"></a>

* Maintain **one unified global exchange rate** for `afiUSD`
* Ensure users on all chains receive proportional yield
* Prevent liquidity fragmentation across deployments

### How Yield Distribution Works <a href="#how-yield-distribution-works" id="how-yield-distribution-works"></a>

#### Step 1: Collect Chain-Level Data <a href="#step-1-collect-chain-level-data" id="step-1-collect-chain-level-data"></a>

* **Vault Deposits:** Track total deposits per chain (e.g., Ethereum: 500K USDC, Arbitrum: 300K USDC)
* **Vault Yields:** Track yield generated by agents on each chain (e.g., Ethereum: 10K USDC, Arbitrum: 3K USDC)

#### Step 2: Aggregate Global Totals <a href="#step-2-aggregate-global-totals" id="step-2-aggregate-global-totals"></a>

Copy

```
totalDeposit = ethDeposit + arbDeposit  
             = 500,000 + 300,000  
             = 800,000 USDC

totalYield = ethYield + arbYield  
           = 10,000 + 3,000  
           = 13,000 USDC
```

#### Step 3: Calculate Global Exchange Rate <a href="#step-3-calculate-global-exchange-rate" id="step-3-calculate-global-exchange-rate"></a>

The exchange rate is updated globally using:

```
newExchangeRate = ((totalDeposit + totalYield) * 1e6) / totalDeposit 
                = ((800,000 + 13,000) * 1,000,000) / 800,000
                = 1,016,250 (scaled by 1e6 for USDC precision)
```

This exchange rate reflects the updated value of 1 vault share across all chains.

#### Step 4: Compute Chain-Specific Yield Distribution <a href="#step-4-compute-chain-specific-yield-distribution" id="step-4-compute-chain-specific-yield-distribution"></a>

```
vaultYield = (newExchangeRate * vaultDeposit) / 1e6 - vaultDeposit
```

For each vault:

* **Ethereum Vault:**

  ```
  ethVaultYield = (1,016,250 * 500,000) / 1,000,000 - 500,000  
                = 8,125 USDC
  ```
* **Arbitrum Vault:**

  ```
  arbVaultYield = (1,016,250 * 300,000) / 1,000,000 - 300,000  
                   = 4,875 USDC
  ```

**Total Distributed Yield:**

```
8,125 + 4,875 = 13,000 USDC (matches total global yield)
```

<table><thead><tr><th width="249">Chain</th><th>Deposits</th><th>Yield Generated</th><th>Yield Distributed</th></tr></thead><tbody><tr><td>ETH</td><td>500,000 USDC</td><td>10,000 USDC</td><td>8,125 USDC</td></tr><tr><td>Arbitrum</td><td>300,000 USDC</td><td>3,000 USDC</td><td>4,875 USDC</td></tr><tr><td><strong>Total</strong></td><td><strong>800,000 USDC</strong></td><td><strong>13,000 USDC</strong></td><td><p><strong>13,000 USDC</strong></p><h3 id="distribution-process"><br></h3></td></tr></tbody></table>

***

### Distribution Process - <a href="#distribution-process" id="distribution-process"></a>

1. **Off-chain Calculation:**
   * Our off-chain Engine collects deposit and yield data from all chains.
   * It computes the new global exchange rate and the yield to distribute to each vault.
2. **On-chain Distribution:**
   * The yield rebalancer (authorized address) calls the `distributeYield` function on each vault’s Yield contract, passing the calculated yield for that vault.
   * The vault contract updates its internal accounting and distributes the yield to users (usually with vesting).


---

# Agent Instructions: 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:

```
GET https://docs.afiprotocol.xyz/proof-of-reserve-vaults/afiusd-vault.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.