RIF Relay Versions

The first iteration of RIF Relay was based on the great work done by the Gas Station Network team.

Version 1

RIF Relay V1 started as a fork of GSN with two goals in mind:

  • Be compatible with existing and future smart contracts without requiring such contracts to be adapted to work with RIF Relay.
  • Be as cost effective as possible.

Version 2


RIF Relay V2 is a redesign of GSN. It reduces gas costs and simplifies the interaction between the different contracts that are part of the system. It achieves this by:

  • Securely deploying counterfactual Smart Wallet proxies for each user account: this eliminates the need for relying on _msgSender() and _msgData() functions, making existing and future contracts compatible with RIF Relay without any modification.
  • Allowing relayers to receive tokens in a worker address under their control and decide what to do with funds later on.
  • Reducing gas costs by optimizing the GSN architecture.

Our main objective is to provide the RSK ecosystem with the means to enable blockchain applications and end-users (wallet-apps) to pay for transaction fees using tokens (e.g. RIF tokens), and thereby remove the need to acquire RBTC in advance.

It is important to recall that - as a security measure - version 1 contracts deployed on Mainnet have limits on the staked amounts to operate; these limits were removed in version 2.


  • RelayHub contract no longer receives payments, the payment for the service (in tokens) is now sent directly to the worker relaying the transaction on behalf of the user.
  • RelayHub contract now handles relay manager staking.
  • Gas estimation improvements:
    • Gas overhead removed from RelayHub; there are no more validations against hardcoded values.
    • The gas and token gas fields from the request can now be left undefined, and in that case, they will automatically be estimated by the RIF Relay Client.
    • The maximum gas estimation in the RIF Relay Server is more precise now.
    • A new utility function is available to estimate the maximum gas a relay transaction would consume, based in a linear fit estimation. This can be used in applications that don’t want to sign a payload each time they need an approximation of the cost of relaying the transaction.
  • Paymaster verifications are done off-chain to optimize gas costs, thus the paymasters are now called Verifiers and they are not part of the on-chain relay flow nor do they handle payments at all.
  • Big gas cost optimization.
  • Security issues fixed.