Aggregators automatically switch the underlying bridge protocol while you are checking quotes, so they can find what looks like the best route. But by the time you are actually ready to sign, the route may have changed. Do not ask how I know.
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Before signing, even if you only stayed on the page for 30 seconds, recheck the four items below. This is not a small detail. It is a habit.
Step 1: Recheck which bridge will actually be used
[What to do]: Confirm which cross-chain bridge will actually execute this transaction, not the first option you saw when you checked the quote.
[How to do it]: In the wallet popup signing request, or on the final confirmation step of the aggregator page, find the "Route" or "Bridge" field. Read the protocol name clearly, such as Across, Connext, Hop Protocol, or another specific bridge.
[Done when]: You can clearly name the bridge protocol this transaction is about to use, instead of just saying "the aggregator picked it for me."
Real example: Some users reported that an aggregator showed the "fastest route" when quoting, but at signing time it actually switched to a bridge with shallower liquidity, causing the final received amount to be about 3% lower than expected. This change happened within a few dozen seconds between quoting and signing. If you do not look again, you will not notice it.
Step 2: Recheck the expected received amount and slippage range
[What to do]: Make sure the final displayed received amount has not clearly drifted from the number you saw when you decided to trade.
[How to do it]: Look at "Minimum Received" or "Expected Output" in the signing request. Compare it with the total estimated cost shown on the aggregator page. If the gap is larger than the slippage tolerance you set, do not sign yet.
[Done when]: You know the minimum amount of assets you will receive after signing, and that number is acceptable to you.
Note: An automatic bridge switch may also mean the liquidity pool on the destination chain has changed. The new pool may be shallower, making the actual received amount lower than the earlier quote. This change usually does not trigger slippage protection, because it happens when your route changes, not when the transaction is executed.
Step 3: Confirm you have enough gas on the destination chain
[What to do]: Make sure you have enough native tokens on the destination chain to pay for gas there. Otherwise your assets may get stuck after crossing chains.
[How to do it]: Check whether the signing request details include a "destination chain gas fee" or "claim fee." If it is not listed separately, go back to the aggregator transaction details page and confirm that operations on the destination chain do not require extra gas, or that the aggregator has already paid it for you.
[Done when]: You have confirmed that after arriving on the destination chain, you do not need to pay extra gas for a "claim" or "release" step, or you already know how much that fee will be.
Common failure reason: Many people ignore destination chain gas fees. Their assets successfully cross to the destination chain, but because the account has no native token on that chain, such as arriving on Arbitrum without ETH, they cannot complete the final "claim" step and the funds get stuck in the contract.
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Step 4: Check the approval amount and avoid leaving unlimited permission
[What to do]: Confirm whether the approval amount you are giving to the aggregator contract has been changed.
[How to do it]: In the wallet signing request, find the "Spending Cap" or "Amount Approved" field. If it shows "Unlimited" or a very large number such as type(uint256).max, you are signing an unlimited approval.
[Done when]: You have confirmed that the approval amount is a limited number close to your transaction amount, not "unlimited." If it is unlimited, reject the signature first, go to the aggregator settings and adjust the approval amount before trying again.
How to verify before completing the operation: In the wallet signature screen, go through the four items above. Confirm it is the bridge you want to use, the expected received amount has not changed, destination chain gas is covered, and the approval amount is limited. Only after all four are confirmed should you click "Confirm" to sign.
