Weth Wrap Unwrap

Wrap native gas tokens (ETH/MATIC) into ERC-20 equivalents (WETH/WMATIC) or unwrap back.

CategoryDeFiUtility

ChainsBASE_ETHETHMATICSETH

Cobo· Author

100 views·8 uses

Overview

Wrap native gas tokens (ETH/MATIC) into ERC-20 equivalents (WETH/WMATIC) or unwrap back.

Facts

•weth9 (ETH): 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2

•weth9 (BASE_ETH): 0x4200000000000000000000000000000000000006

•weth9 (SETH): 0xfFf9976782d46CC05630D1f6eBAb18b2324d6B14

•wmatic (MATIC): 0x0d500B1d8E8eF31E21C99d1Db9A6444d3ADf1270

•weth (MATIC, bridged ERC-20): 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619 — no deposit/withdraw; obtain via bridge only

•selector deposit(): 0xd0e30db0

•selector withdraw(uint256): 0x2e1a7d4d

•target_in: weth9 / wmatic contract only

Functions:

solidity

function deposit() external payable;
function withdraw(uint256 wad) external;
function approve(address guy, uint256 wad) external returns (bool);

Typical Flows

### Wrap — 1 tx

Send native ETH (or MATIC) directly to deposit() with a value:

text

tx.to    = weth9_address
tx.value = amount_in_wei          # e.g., 1e18 for 1 ETH
tx.data  = 0xd0e30db0             # deposit() selector, no args

### Unwrap — 1 tx

Call withdraw(wad) to receive native ETH back:

text

tx.to   = weth9_address
tx.data = 0x2e1a7d4d
        | 0x{wad_32B}             # amount to unwrap in wei

### Typical DeFi setup flow (wrap → approve → protocol)

1.deposit() on WETH9 with value = amount — wrap ETH into WETH

2.approve(protocol_contract, amount) on WETH9 — grant protocol spend allowance

3.Call the protocol (e.g., Uniswap exactInputSingle, Aave supply, etc.)

Policy Controls

•No approve step for wrap: deposit() takes ETH as msg.value — no prior ERC-20 approve is needed.

•Bridged WETH on Polygon is NOT wrappable: 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619 is an ERC-20 bridged from Ethereum — deposit() on it does not work. Use the Polygon bridge to obtain it.

•WMATIC ≠ WETH: On MATIC, deposit()/withdraw() on WMATIC wraps the native gas token MATIC, not ETH.

•Do not send ETH directly to the contract address: always call deposit() with calldata 0xd0e30db0; some WETH9 deployments have a fallback that calls deposit(), but relying on it is not safe.

•Not applicable for: cross-chain bridging of ETH — use bridge-wormhole or bridge-layerzero; liquid staking (ETH → stETH/cbETH) — use dedicated staking protocols

•Testnet: No real value; SETH tokens are worthless.

•Partial reference: use web search for unlisted tokens, contracts, parameters, or up-to-date addresses

References

•Docs: https://ethereum.org/llms.txt — WETH9 contract ABI, Ethereum EVM spec, ERC-20 standard, WETH9 contract patterns.