Why Cross-Chain Swap Gas Leaves Transactions Stuck

A cross-chain swap can be stuck because the source-chain transaction has not paid enough gas to be included, even when the swap quote is ready. The quote describes the intended trade; your wallet still has to send the asset on its original network. If that transaction sits pending, the swap cannot start. Later, the destination network’s fee is usually accounted for in the quoted output, so it is a different cost from the gas your wallet needs to send the swap.

Why is a cross-chain swap transaction stuck?

Most often, the source-chain transaction is waiting for a miner or validator to include it. On EVM networks, a fee that is low compared with current demand can leave a transaction pending, and a later transaction from the same wallet may also wait behind it because both use the same account nonce. On other chains, fee rules and ways to speed up a transaction differ. A swap interface may show “pending” simply because it is waiting for confirmation of this first step. For the broader sequence from quote to receipt, see thor swap.

How can you tell which gas is missing?

Check the source-chain transaction in your wallet or a block explorer, then compare its status with the swap’s status. These clues help separate a slow transaction from a swap that has already begun:

• Pending on the source chain: the inbound transfer has not confirmed; the swap has not started.
• Confirmed on the source chain: the protocol or service can now process the inbound transfer, subject to its confirmation and processing time.
• Swap processed, output not received: check the destination address and transaction status on the destination chain; the output may still be waiting to be sent or confirmed.

What should you do about a pending swap?

Start with the transaction status, because the safe next step depends on whether the source transfer has already confirmed. If it is still pending, use the wallet’s fee-bump or replacement option only if that network supports it; on EVM chains, a replacement generally needs the same nonce and a higher fee. Do not send the swap amount again while the original transaction’s status is unclear, since both transactions could complete.

1. Open the source transaction in your wallet or a block explorer and confirm its network and status.
2. If it is pending, check the wallet’s supported speed-up or replacement method and review the fee before signing.
3. If it is confirmed, look up the swap or transfer through the service’s status page and follow its stated recovery or support process.
4. Before retrying, confirm the destination address and leave enough of the source asset in your wallet to pay network gas.

Keep the two fees distinct: source gas pays to submit the transfer, while the destination-side fee affects what arrives. For most users, checking the transaction stage first is the best way to avoid paying source gas twice or troubleshooting the wrong chain.