How to Trade Through Fermi Swap and Verify the Fill

A fermi swap moves tokens when your wallet authorises a transaction and the Ethereum network executes it against FermiSwap’s available inventory. The quote is an estimate; the confirmed transaction receipt shows whether the swap succeeded and how much each side transferred. To place one, choose the token pair and amount, review the expected output, approve the input token if needed, then sign the swap.

How does a fermi swap work?

First, the interface reads the tokens and amount you selected and requests a quote. FermiSwap is a proprietary automated market maker: it fills trades from its own token inventory rather than matching your order with another trader or drawing from a shared pool. That inventory affects how much output it can offer for a given input.

Next, your wallet may ask you to approve the input token. An approval lets the swap contract spend that token on your behalf; it is a separate permission from the swap itself. Then the wallet presents the swap transaction for signing. The contract checks the trade parameters and attempts to exchange the specified tokens. You can think of the quote as a till display and the transaction as the payment: only the completed payment records what you actually received.

When you review fermi swap, treat the displayed output as a proposed amount, not proof of execution. Compare it with the amount you need and any minimum-output limit shown before signing. If the price moves or the requested trade no longer fits the available inventory, execution may fail or return less than the quote, depending on the transaction’s conditions.

What should you check before signing a fermi swap?

Check the network, token addresses, input amount, quoted output and recipient address. Token symbols can be duplicated, so verify the token identity in the wallet or interface when you are unsure. Review the approval request separately: it should concern the input token needed for the trade, and the spender should match the swap flow you intended to use.

Pay attention to the minimum output if the transaction provides one. It sets a floor for the amount you will accept. A tighter floor limits how much the result can worsen before the transaction reverts, but it can also make the trade fail when the quote changes. A looser floor gives execution more room while accepting a worse possible rate. Choose based on the trade you are willing to accept, rather than changing it just to force a transaction through.

Also account for the network fee. A failed transaction can still consume gas because the network processed the attempt, even though the token swap did not complete. Do not sign a transaction whose token pair, amount or recipient differs from what you entered.

How do you verify a Fermi Swap fill?

After signing, open the transaction in an Ethereum block explorer using the transaction hash from your wallet. Wait for confirmation, then check the status. A successful status means the transaction executed; a pending transaction is not yet a confirmed fill, and a failed one did not complete the swap.

For a successful transaction, inspect the receipt’s token transfers. Confirm that the intended input token left your wallet and that the intended output token reached the recipient address. Compare the actual amounts in the receipt with the quote and your minimum-output condition. The difference is the realised exchange rate for this execution; it can include price movement and any applicable charges.

FermiSwap’s swap contract also emits a FermiSwap event with the recipient, input token, output token, input amount and output amount. Check that the event belongs to the transaction you sent and that its token addresses and recipient match your trade. The event and transfer records provide a direct on-chain check of the fill. If the transaction succeeded but the amounts or recipient do not match your expectation, use the receipt to identify what happened before attempting another swap.

What does a confirmed fill tell you?

A confirmed fill tells you what the transaction delivered, not whether the price was favourable compared with every other route. The quote helped you decide whether to proceed; the receipt establishes the actual result. For a small trade, checking the wallet balance change may be enough. For a larger one, inspect both the event and token transfers, and calculate the received amount against the amount spent.

The practical sequence is simple: verify the assets and recipient, set an output floor you can accept, sign only the intended transaction, then confirm its status and receipt. That turns a displayed estimate into a verifiable record of what the fermi swap actually did.