What is WMON (Wrapped Monad)?

2 min read · Updated 2026-04-22

WMON is Wrapped MON, an ERC-20 token that represents 1 MON, one-to-one, redeemable any time. It exists because most smart contract interfaces, including UniswapV2, expect ERC-20 tokens, while Monad's native gas token (MON) is not an ERC-20.

Why wrapping exists

Native tokens like MON (or ETH on Ethereum) are handled by the protocol itself, not by an ERC-20 contract. Many DeFi primitives, including routers, pools, and lending markets, are built around the ERC-20 interface. Wrapping converts native MON into an ERC-20 equivalent so those contracts can hold, transfer, and approve it like any other token.

Wrapping and unwrapping

The WMON contract has two functions:

• deposit(): send N native MON, receive N WMON.
• withdraw(uint256): burn N WMON, receive N native MON.

The ratio is always 1:1, with no fee. The contract holds 100% reserves in native MON at all times.

How PuddleSwap handles this for you

When you select MON as the input or output of a swap, PuddleSwap's router wraps or unwraps automatically as part of the same transaction. You never have to manually wrap MON unless you want WMON as the literal output token. If a route shows WMON as a hop, that's the wrapped form participating in the pool.

When to use WMON directly

• You want to hold WMON as an ERC-20 balance (transfers to other addresses, approvals).
• You're adding liquidity to a MON-based pool. The underlying pair is WMON, so you deposit WMON alongside the other token.
• You're building a contract that expects ERC-20 inputs.

When NOT to wrap manually

For most users on PuddleSwap, manual wrapping is unnecessary. The swap router calls deposit and withdraw on your behalf when MON is the input or output of a swap. Manually wrapping first wastes gas, because you pay for the wrap transaction and then any subsequent transfer separately, where the router would batch wrap-and-swap into a single call.

Wrap manually only when you need a standing WMON balance for non-swap purposes, when you are adding liquidity to a pool that pairs against WMON specifically, or when a contract you are calling requires ERC-20 input.

WMON vs. WETH

WMON works the same way Wrapped Ether (WETH) works on Ethereum. Same interface, same 1:1 ratio, same purpose: turn the native gas token into an ERC-20 that smart contracts can hold and transfer. The contract code is also nearly identical, since most chains adopt the canonical WETH9 contract verbatim with the symbol changed.

If you have used WETH on a Uniswap V2 pool, WMON on PuddleSwap behaves the same. The only practical differences are the chain ID and which native token is being wrapped.

Swap MON on PuddleSwap. The router wraps and unwraps automatically. For contract details and live pools, see the WMON token page.