Faster source gas buys inclusion, not a cheaper swap

Faster source gas costs the difference between the chain’s faster and slower fee rates, multiplied by the transaction’s size. On a THORChain swap, that premium pays the source network to include the deposit sooner; it does not reduce THORChain’s liquidity fee or the fee for sending the output. Whether it is worth paying depends on the chain’s current congestion and the cost of a delayed or refunded swap.

What does faster source gas pay for?

It pays the source chain’s validators or miners to process the transaction that sends the swap asset to THORChain. The wallet chooses a fee rate when it builds that transaction. On a UTXO chain such as Bitcoin, the fee generally follows the rate per virtual byte and the transaction’s virtual size; on an account-based chain such as Ethereum, it depends on the gas used and the fee parameters. The faster option raises the fee rate or priority offered to the network.

THORChain’s inbound fee is calculated as the source-chain gas rate multiplied by an estimated transaction size. The gas itself is paid by the user on the source chain, often in that chain’s native asset. A token swap on Ethereum, for example, still needs ETH to pay for the transaction that transfers the token. The wallet’s estimate is specific to the transaction and network conditions; the swap amount does not make a fixed “fast fee” apply to every transfer.

The premium is therefore a local fee comparison: subtract the slower rate from the faster rate, then multiply by the estimated transaction size. To judge the amount in dollars or against the swap value, convert that difference from the source chain’s gas asset. A wallet may label its choices “standard,” “fast,” or “urgent,” but those labels are interface estimates, not THORChain fee categories. The thor swap guide covers route selection in more detail; the source fee is only one part of the route’s total cost.

Does paying more make the whole swap faster?

No: it targets the source transaction’s inclusion time. Once the deposit is confirmed, THORChain still has to observe it, reach the required agreement among nodes, process the swap and arrange the outbound transaction. Then the destination chain must confirm delivery. A faster source fee cannot shorten those later steps or make the destination chain cheaper.

For a THORChain swap, the network’s fee breakdown separates the source-chain inbound fee from the liquidity fee and the destination-chain outbound fee. The inbound fee is paid to the source chain; the liquidity fee is deducted during the swap according to the trade and pool conditions; the outbound fee is taken from the output to cover delivery gas and protocol overhead. An optional affiliate fee may also apply. Raising the source gas rate changes only the first component, while the outbound cost responds to the destination chain and THORChain’s fee rules.

That distinction matters when comparing routes. A route with a cheaper source transaction can still have a larger outbound charge or a higher liquidity fee. Conversely, a source chain with a temporarily busy mempool may make faster inclusion expensive while the rest of the route remains unchanged. Compare the itemized quote and wallet fee before signing, and keep the source fee separate from the amount being swapped.

When is the faster fee worth paying?

It is worth considering when a slow confirmation could make the expected swap conditions unusable. THORChain’s developer guidance recommends a fast source-chain gas rate because a delayed inbound can leave the user waiting and expose the transaction to stale pricing or a refund. A market swap can also have a price limit: if the resulting trade does not meet that limit, the transaction may be refunded rather than completed at a worse price.

That risk is not the same as a guaranteed loss from choosing the slower wallet setting. The faster rate buys a better chance of timely inclusion; it cannot guarantee confirmation by a precise deadline, a particular swap price or successful delivery. The relevant comparison is the extra source fee against the possible cost of delay under the current network conditions.

• Check the wallet’s fee estimate for the actual source transaction, not a generic chain average.
• Compare the faster and slower rates, then value their difference in the gas asset and in the swap’s fiat value.
• Review the quote’s expected output, fee breakdown and price limit before signing.
• Keep enough native gas asset for the source transaction, especially when swapping a token.

What can a refund cost?

A refund is a separate outbound transaction, so it does not erase the source fee already paid to submit the deposit. THORChain’s fee guidance says a failed swap is refunded on the source chain and incurs that chain’s outbound fee, rather than the destination chain’s outbound fee. The precise deduction depends on the applicable fee at processing time. Small swaps have less room to absorb that cost, which makes the quote’s minimum amount and fee estimates especially relevant.

The practical rule is to pay for the source-chain urgency the transaction needs, not to treat “fast” as a way to accelerate every stage. When a delay could invalidate the quoted conditions, the rate premium may be rational insurance against waiting into a refund. When confirmation timing is not material, the incremental fee is simply extra source-chain cost. In either case, it is distinct from the protocol and destination fees that determine how much arrives.