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Gas is the unit of measure for how much computational work is required to process transactions and smart contracts. Essentially a transaction fee, the term originates from Ethereum, in which context it refers to computation undertaken on the Ethereum Virtual Machine (EVM). Since Ethereum was founded, numerous EVM-compatible (and non-EVM-compatible!) networks have emerged and adopted similar models.

The term can be considered analogous to the gas that powers a car engine: it’s the fluctuating, occasionally expensive cost of operation. More complex smart contracts require more gas to power their computation, just as a bigger, more powerful car takes more gas to run.

The method for calculating gas fees varies depending on the network. For example, calculating gas on Ethereum used to be very complicated, but was considerably simplified with the implementation of Ethereum Improvement Protocol (EIP) 1559 in August 2021 (also known as the London Upgrade, following the Ethereum convention of naming major upgrades after places that have hosted its conferences). Essentially, you pay a base fee for every unit of gas, which is burned, or disappears, upon successful completion of the transaction. On top of the base fee, you add a priority fee, again per unit of gas, the value of which depends on how quickly you want the transaction to go through. 

Across the broad range of EVM-compatible networks available, gas, or similarly-functioning alternatives, have essentially become the standard method of calculating transaction costs. Fees are paid in the network’s native token: for example, any transaction on Ethereum requires ETH; using BSC requires BNB; using Polygon requires MATIC. Some networks have adopted Ethereum’s EIP-1559 model wholesale, such as Polygon, whilst others have made adjustments, including Avalanche, for their C-Chain (which burns both the base fee and priority fee, rather than just the former).  

Here are some essential details for dealing with gas in GPEX Clip:

The gas limit

The gas limit is the maximum number of units of gas you are willing to pay for in order to carry out a transaction or EVM operation. Remember, a normal transaction sending ETH or a token normally costs 21,000 gas. Many networks, such as EVM-compatible blockchain Harmony, use an identical model in which standard transactions also cost 21,000 gas.  

The priority fee

The priority fee, also referred to as the “miner tip”, incentivizes the miner to prioritize your transaction. Naturally, whether this does actually go to a miner depends on the consensus mechanism they use: Ethereum mainnet currently relies on miners as part of a proof-of-work system, whereas other blockchains, such as BSC, may be proof-of-stake. In such cases, the recipients of the “tip” are validators, rather than miners. 

The max fee

The max fee is the total, global amount paid for your transaction. It is calculated as: (base fee + priority fee) x units of gas used. GPEX Clip initially sets this amount based on the previous block’s history. However, users can edit this amount through custom settings (see below). The difference between max fee per gas and base fee + max priority fee per gas is “refunded” to the user.

Additional Concepts


Gwei is a unit of ether, the smallest denomination, which stands for gigawei (or 1,000,000,000). Gwei is used for gas fees, or rather payments made by users to compensate for the computing energy required to process and validate transactions on the Ethereum blockchain. Other networks also tend to calculate costs using gwei — for example, Fantom, Harmony and Avalanche. 


Slippage is the expected percentage difference between a quoted and an executed price.

Gas fee

Gas fee refers to the transaction fee on the Ethereum blockchain. It is what users pay to get their transaction validated, or completed.

Base fee

Generated by the protocol. Represents the minimum ‘gasUsed’ multiplier required for a transaction to be included in a block (i.e. for a transaction to be completed). This is the part of the transaction fee that is burnt.

Internal transactions

At times, you may interact with a dapp, and expect to see a transaction record in GPEX Clip, but you don’t. Your next step, as always, should be to verify on a block explorer whether the transaction occurred. Even then, though, you might not see it, if it is an internal transaction.

So if you’re looking for a transaction and don’t see it anywhere, check under the ‘Internal Transactions’ tab in Etherscan.

Why aren’t internal transactions displayed in my wallet activity/history?

When we talk about a ‘transaction’, we are referring to the act of an amount being deducted from one account, and that amount being added to the balance of another account. However, as more sophisticated dapps are created, there are other things that happen on the blockchain that aren’t “simple transfers”.

An internal transaction is an action that is occurring within, or between, one or multiple smart contracts. In other words, it is initiated inside the code itself, rather than externally, from a wallet address controlled by a human.

Often, the end result of the internal transaction is that one address or another will end up with more tokens of some kind; for example, if you’re minting DAI, or if you’re reserving an ENS name (in the latter case, you end up with that ENS name in your wallet).

Currently, GPEX Clip does not show internal transactions in your transaction activity or history, only standard transactions between addresses.

That said, there is no difference between tokens received through an internal transaction, and those received through a standard transaction. The transfer of funds is reflected in the overall balance of the account.

The reason GPEX Clip does not show these internal transactions is mainly a technical one; internal transactions, being somewhat “ephemeral” in nature (they occur while the code is running), are not recorded on the blockchain. There are some services, like Etherscan, that track internal transactions.