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

# CT Wrapper

> The CTWrapper Smart Contract

# CT Wrapper Contract

The `CTWrapper` is a pivotal contract in the Bayex ecosystem. It serves as a bridge between the **ERC1155** tokens used by the Conditional Tokens Framework and the **ERC20** standard required by most DeFi applications, including Uniswap V4.

## Key Functions

### `wrap`

Wraps ERC1155 conditional tokens into ERC20 tokens.

* **Inputs**: `ctid` (uint256), `amount` (uint256), `name` (string), `symbol` (string).
* **Logic**: Transfers the ERC1155 tokens from the user to the Wrapper contract using `safeTransferFrom`. Mints the corresponding amount of ERC20 tokens to the user.
* **Design**: Encodes `name` and `symbol` as data for the transfer.

### `unwrap`

Unwraps ERC20 tokens back into the underlying ERC1155 conditional tokens.

* **Inputs**: `ctid` (uint256), `amount` (uint256).
* **Logic**: Burns the user's ERC20 tokens and transfers the stored ERC1155 tokens back to the user via `safeTransferFrom`.
* **Event**: Emits `Unwrapped(caller, ctid, amount)`.

### `predictTokenAddress` (CREATE3)

Returns the deterministic address for a given condition ID before deployment.

* **Logic**: `CREATE3.predictDeterministicAddress(keccak256(ctid), address(this))`
* **Benefit**: Allows the frontend to know the token address without querying the blockchain state significantly.

## Admin Functions

The contract owner has specific privileges to maintain metadata quality:

* **`updateBaseURI`**: sets the base URI for the deployed ERC20 tokens.
* **`updateTrimSize`**: Updates the string trimming size (default: **32 bytes**).
* **`updateTokenMetadata`**: Fixes the metadata (name/symbol/uri) of an already deployed token if initial values were incorrect.

## Design Decisions

### ERC1155 Receiver Hooks

The contract implements `onERC1155Received` and `onERC1155BatchReceived`.

* **Feature**: This enables "push" wrapping patterns. Users can send tokens *to* the wrapper to wrap them in a single transaction.
* **Auto-Wrap**: If tokens are received with data encoding `(string name, string symbol)`, they are automatically wrapped and ERC20s are minted to the sender.

### Gas Optimization

* **String Trimming**: To prevent gas griefing or excessive storage costs, names and symbols are trimmed to a fixed size (default: 32 bytes) using the internal `_trim` function.
* **CREATE3**: Ensures address determinism regardless of the salt or bytecode changes, simplifying indexer logic.

## Events

```solidity theme={null}
event TokenDeployed(uint256 indexed ctid, address token, bytes32 salt);
event Wrapped(address indexed caller, uint256 indexed ctid, uint256 amount);
event Unwrapped(address indexed caller, uint256 indexed ctid, uint256 amount);
```