Gas is the execution fee for every operation made on ethereum. Its price is expressed in ether and it's decided by the miners, which can refuse to process transaction with less than a certain gas price. (more infos)
To pay for the gas, users first need an account containing some Ether. The problem is converting fiat currency into Ether is complicated. The process require the user to send his passport, bank account and most of time to wait few days to be validated. This can be a pain or even a complete showstopper for developers or users of Dapps.
To solve this problem, so we provide "Identities" that allows users to send transaction without having to pay for the gas. An identity is a deployed smart contract that represents yourself on the Blockchain.
We use Meta Transaction to take care of the gas. This is based on the principle of off-chain message signing for on-chain use. When you create an Identity, Rockside creates an EOA and deploys a smart contract which can execute transactions on behalf of this EOA. The contract can be called with transaction data that has been signed by the EOA. The contract will only execute the transaction if the signature comes from its owner. Rockside contracts are available on our github.
Because Rockside also manage the EOA associated with the contract, you just have to provide from, to and data parameters to send a transaction.
When you send transaction using your identity, rockside relay your transaction and pay for the gas.
On mainnet for a limited number of transaction, it's totally free. On entreprise plan, gas fee will be charged at the end of the month.