> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tiltprotocol.com/llms.txt
> Use this file to discover all available pages before exploring further.

# BaseVault

> Abstract ERC-4626 vault base — deposits, withdrawals, NAV, and allocation

# BaseVault

`BaseVault` is the abstract base contract that all Tilt vaults inherit from. It implements the ERC-4626 tokenized vault standard with multi-token portfolio management.

## Overview

BaseVault manages the full lifecycle of a decentralized fund:

* Accepting deposits (minting shares)
* Processing withdrawals (burning shares, liquidating tokens)
* Calculating NAV across multiple held tokens
* Allocating idle capital into target positions
* Rebalancing the portfolio to match target weights
* Accruing and distributing fees

## Deposit Flow

1. Investor calls `deposit(assets, receiver)` with tiltUSDC
2. Entry fee is deducted and sent to `FeeManager`
3. Shares are minted to the receiver: `shares = (netAssets * totalSupply) / totalAssets`
4. Deposited tiltUSDC is added to `unallocatedDeposits`
5. Funds remain idle until `allocateIdleAssets()` is called

## Withdrawal Flow

1. Investor calls `withdraw(assets, receiver, owner)` or `redeem(shares, receiver, owner)`
2. The vault calculates the tiltUSDC amount owed
3. If insufficient idle tiltUSDC, `_ensureBaseLiquidity()` auto-liquidates held tokens via `TokenRouter`
4. Exit fee is deducted
5. Net tiltUSDC is transferred to the receiver
6. Shares are burned

Withdrawals are **never paused** — this is a core safety invariant.

## NAV Calculation

```solidity theme={null}
function totalAssets() public view returns (uint256) {
    uint256 total = baseAsset.balanceOf(address(this));
    for (uint i = 0; i < heldTokens.length; i++) {
        uint256 balance = heldTokens[i].balanceOf(address(this));
        uint256 price = tokenRouter.getTokenPrice(heldTokens[i]);
        total += (balance * price) / 1e18; // normalize to base asset decimals
    }
    return total;
}
```

## Allocation

`allocateIdleAssets()` deploys unallocated tiltUSDC into target positions:

* Permissionless — anyone can call it
* Calculates buy amounts: `buyAmount = allocatable * weightBps / 10000`
* Executes purchases through `TokenRouter`
* Only buys; never sells existing positions

## Rebalancing

`rebalance()` aligns the portfolio to target weights:

* Calculates current weight of each token
* Determines sell orders for over-weight tokens
* Determines buy orders for under-weight tokens
* Executes all trades through `RebalanceEngine`
* Restricted to authorized callers (curator or engine)

## Fee Accrual

* **Entry/exit fees**: collected in tiltUSDC at transaction time
* **Management fees**: accrued continuously via share dilution
* **Performance fees**: accrued above high-water mark via share dilution
* All fees split between protocol treasury and curator via `FeeManager`

## Dead Shares

The first 1,000 shares are minted to `address(1)` on vault initialization. This permanently locks a small amount of shares, preventing the first-depositor inflation attack common to ERC-4626 vaults.

## Safety

* Reentrancy guards on all state-changing operations
* Ceiling-division rounding on withdrawals (protects vault from rounding exploits)
* Token count cap (30 max) prevents gas DoS
* Slippage protection on all swaps