Gas and Fees

Gas and Fees

Learn about the differences between Gas and Fees on Injective.

Pre-requisite Readings -> Cosmos SDK Gas

Gas represents the amount of computational effort required to execute specific operations on the state machine.

Injective utilizes the concept of gas to track the resource usage of operations during execution. Operations on Injective are represented as read or writes done to the chain's store.

A fee is calculated and charged to the user during a message execution. This fee is calculated from the sum of all gas consumed in a message execution:

fee = gas * gas price

Gas is used to make sure that operations do not require an excess amount of computational power to complete, and to deter bad-acting users from spamming the network.

Minimum gas price: The minimum gas price set by validators is currently 160,000,000inj. To find the amount paid in inj, multiply the gas price by the gas amount and divide by 1e18 (INJ has 18 decimals).

For example: if gasWanted is 104,519, then gasFees = 160,000,000 * 104,519 / 1e18 = 0.000016723inj

Cosmos SDK Gas

In the Cosmos SDK, gas is tracked in the main GasMeter and the BlockGasMeter:

• GasMeter: keeps track of the gas consumed during executions that lead to state transitions. It is reset on every transaction execution.

• BlockGasMeter: keeps track of the gas consumed in a block and enforces that the gas does not go over a predefined limit. This limit is defined in the Tendermint consensus parameters and can be changed via governance parameter change proposals.

More information regarding gas in Cosmos SDK can be found here.

In Cosmos, there are types of operations that are not triggered by transactions that can also result in state transitions. Concrete examples are the BeginBlock and EndBlock operations and the AnteHandler checks, which might also read and write to the store before running the state transition from a transaction.

BeginBlock and EndBlock

These operations are defined by the Tendermint Core's Application Blockchain Interface (ABCI) and are defined by each Cosmos SDK module. As their name suggest, they are executed at the beginning and at the end of each block processing respectively (i.e., pre- and post-transaction execution).

AnteHandler

The Cosmos SDK AnteHandler performs basic checks prior to transaction execution. These checks are usually signature verification, transaction field validation, transaction fees, etc.