Mantle is an Ethereum layer 2 that uses the same address format as Ethereum. One paste covers your whole position on the chain.
What sets it apart from most layer 2s is the gas token. Fees on Mantle are paid in MNT, not ETH. Every transaction you make is a small MNT disposal, and tools that assume ETH get the fee figures wrong.
That also catches people out on their first bridge: arriving with only ETH leaves you unable to pay for anything until you have some MNT.
What you get out of the box
Pick your import method.
On Mantle
- Open your wallet and copy your address. It starts with 0x and matches your Ethereum address.
On Kryptos
- Go to Kryptos.io and sign up with your Google account.
- From the menu, click Integrations.
- Click Add Integration and search for Mantle.
- Click the Mantle icon, then choose Import using Address.
- Give the wallet a name, paste your address, and click Import Your Transactions.
Good to know
- Fees are charged in MNT. If your report shows ETH gas on Mantle, something has read the chain as a standard layer 2.
- MNT exists in two forms: a token on Ethereum and the native coin on Mantle. Same name, two separate balances.
- If you held BIT before 2023, it became MNT in a one-for-one swap. The price you paid for the BIT is the cost that carries into your MNT.
Why the gas token changes your numbers
Nearly every Ethereum layer 2 charges fees in ETH. Mantle charges in MNT, and that one difference ripples through a tax report.
It changes which asset you are disposing of. A year of trading on Base produces hundreds of small ETH disposals; the same year on Mantle produces hundreds of small MNT disposals, priced against a different chart. Get the asset wrong and every fee is valued wrong.
It also changes what a first-time user needs. Bridging ETH across without any MNT leaves you holding funds you cannot move, because there is nothing to pay the fee with. Most people solve it by buying a small amount of MNT first, and that purchase is itself a trade worth recording.
For how fees affect gains where you file, see the USA crypto tax guide or the UK crypto tax guide.
Staked ETH that never changes quantity
mETH is a receipt for ETH you have staked. The confusing part is that it pays nothing out.
Liquid staking comes in two shapes. Some tokens rebase: your balance grows a little every day, and each increase is a receipt you may owe tax on. Others accrue value: the balance sits still while each token becomes worth more ETH. mETH is the second kind.
For your records, that means a long holding period with nothing happening, then one event at the end. When you redeem mETH for ETH or sell it, the difference between what you put in and what you take out is the whole gain, realised at once. Nobody needs to hunt for daily reward entries, because there are none.
cmETH is a further layer on top, and it does pay claimable rewards. If you hold cmETH rather than plain mETH, those claims are separate receipts and want recording on the day they arrive.
Manage your Mantle portfolio with Kryptos.
Staking ETH into mETH
mETH grows in value rather than in quantity, so your balance never moves while the reward builds up inside it. The gain surfaces when you redeem or sell, and Kryptos measures it then.
Paying fees in MNT
Every transaction spends MNT rather than ETH. Over an active year that is a long list of small MNT disposals that has to be priced correctly.
Carrying BIT cost into MNT
Anyone who held BitDAO's BIT went through a one-for-one swap into MNT. The original purchase price carries over, and losing it means starting your MNT history from zero cost.
Audit-ready, automatically.
Once your wallets and exchanges are connected, generating a tax report takes a single click. Open Reports from the menu, choose your jurisdiction, and download.
mETH accrues value, it does not rebase
The quantity in your wallet stays the same and the value per token rises. Nothing is taxable while you hold, because nothing arrives. The whole gain lands when you redeem or sell.
cmETH rewards are separate
cmETH sits on top of mETH and pays restaking rewards you claim yourself. Those claims are receipts in their own right, on top of whatever mETH has accrued underneath.
Gas disposals are in MNT
Fees leave your MNT balance, so each one is an MNT disposal priced on the day. Tools that assume every layer 2 charges ETH will value these wrongly.
The BIT swap is a substitution, not a sale
Swapping BIT for MNT one for one replaced the token without changing what you owned. Treat it as continuing the same holding and carry the original cost across.
Read-only by design.
- Kryptos only ever needs your public wallet address
- A public address is read-only. It can't move or spend anything
- We never ask for your recovery phrase or private key
- Remove a wallet whenever you like, and its data goes with it
If something doesn't sync.
Check that fees are showing in MNT. Mantle prices gas in its own token, and a report showing ETH fees has read the chain with the wrong assumption.
That is correct while you hold it. mETH gains value rather than paying anything out, so the gain appears when you redeem.
If it came from the BIT swap, import the wallet or exchange account that held the BIT. The cost carries forward from there.
Still stuck? Email support@kryptos.io or open live chat from the app.