ethers.js

ethers.js is a library for interacting with an ethereum and its ecosystem.

• Signers
• Providers

gasLimit ​

In ethers it's possible to limit how much of gas the users may pay for calling the function.

contract.functionToCall(message, { gasLimit: 300000 });

This way makes the user pay a set amount of gas of 300,000. I he don't use all of it in the transaction he'll automatically be refunded (if a transaction costs 250,000 gas then after that transaction is finalized that 50,000 gas left over that the user didn't use will be refunded).