# Vesting Contracts

### Key Features

* **Flexible Vesting Schedules**: Configure start time, cliff period, duration, and release intervals
* **Access Control**: Role-based permissions for administrative functions
* **Safety Features**: Includes reentrancy protection and pausable functionality
* **Virtual Token**: ERC20-compatible representation of vested tokens (non-transferable)
* **Merkle Tree Support**: Efficient distribution of vesting schedules
* **Purchase Options**: Optional ETH payment for vesting schedule creation

{% embed url="<https://github.com/bio-xyz/vesting-contracts>" %}

## Contracts

### TokenVesting Contract

The base vesting contract that implements core vesting functionality and virtual token features.

**Features**

* **Vesting Schedule Management**:
  * Configurable start time, cliff period, and duration
  * Customizable slice periods for gradual token release
  * Optional revocability per schedule
  * Admin controls for schedule management
* **Virtual Token Implementation**:
  * ERC20-compatible interface
  * Non-transferable by design
  * Balance represents vested tokens
  * Automatic balance updates on vesting events
* **Access Control**:
  * `DEFAULT_ADMIN_ROLE`: Can manage vesting schedules and contract settings
  * `VESTING_CREATOR_ROLE`: Can create new vesting schedules

**Inheritance**

* OpenZeppelin's AccessControlDefaultAdminRules
* OpenZeppelin's ReentrancyGuard
* OpenZeppelin's Pausable
* IERC20Metadata

**Key Functions**

* `createVestingSchedule()`: Creates new vesting schedules
* `release()`: Releases vested tokens to beneficiaries
* `revoke()`: Allows admin to revoke revocable schedules
* `withdraw()`: Enables admin to withdraw unused tokens

**Security Features**

* Reentrancy protection on critical functions
* Pausable functionality for emergency stops
* Role-based access control
* Comprehensive input validation

### TokenVestingMerkle Contract

Extends TokenVesting with Merkle tree functionality for efficient schedule distribution.

**Features**

* **Merkle Tree Integration**:
  * Efficient proof verification
  * Prevention of double-claiming
  * Batch schedule distribution support

**Inheritance**

* TokenVesting

**Key Functions**

* `claimSchedule()`: Claims vesting schedule using Merkle proof
* `updateMerkleRoot()`: Updates the Merkle root
* `scheduleClaimed()`: Checks if a schedule has been claimed

### TokenVestingMerklePurchasable Contract

Extends TokenVestingMerkle with purchasing capabilities.

**Features**

* **Purchase Mechanism**:
  * ETH payments for vesting schedules
  * Configurable cost per vToken
  * Customizable payment receiver

**Inheritance**

* TokenVestingMerkle

**Key Functions**

* `claimSchedule()`: Claims schedule with payment
* `setVTokenCost()`: Updates the cost per vToken
* `setPaymentReceiver()`: Sets payment receiver address

### Deprecated Contracts

Located in `src/deprecated/`:

**MultiTokenVesting**

* Enables querying vesting balances across multiple contracts
* Supports external vesting contract integration

**MultiTokenVestingMerklePurchasable**

* Combines MultiTokenVesting and TokenVestingMerklePurchasable
* Supports cross-contract schedule verification