Jito Tip Router Program

Overview

Current Process

Each validator has a unique tip distribution account, owned by the Jito Tip Distribution Program, where SOL is collected for a given epoch.
At the end of the epoch, an off-chain process takes place which produces a merkle tree and merkle root for each validator’s tip distribution account.
- Validators can run this process themselves or delegate it to another party.
- The merkle tree is intended to distribute any SOL in the account to the validator based on their MEV commission rate. Remaining funds are sent to stakers’ stake accounts pro-rata.
After the merkle root has been uploaded, merkle proofs are uploaded on-chain and the program will transfer SOL from the tip distribution account to the validator’s vote account and stake accounts.

Problem

Merkle root upload authority is permissioned with opt-in from each Jito-Solana validator. This mechanism creates a single point of potential failure with adverse impacts on network stakeholders and lacks transparency on the calculation.

Solution

The TipRouter NCN will leverage Jito (Re)staking to empower a set of node operators to come to consensus on the correct merkle root for tip distribution.

The mechanism of the TipRouter NCN is detailed below:

Validators can delegate the merkle root upload authority to a program derived address owned by the NCN, giving it permission to upload merkle roots.
After the epoch rollover, node operators will compute a 'meta merkle root' — a merkle root derived from a new merkle tree containing all validator merkle trees — and upload it on-chain. This change reduces the number of votes required, as operators now vote on the meta merkle root instead of casting individual votes for each validator.

Tips

Inside of Stake Meta:

validator_vote_account: The account representing the validator's voting authority.
validator_node_pubkey: The public key of the validator node.
maybe_tip_distribution_meta: Metadata related to tip distribution, if applicable.
- merkle_root_upload_authority: The authority responsible for uploading the merkle root.
- tip_distribution_pubkey: The public key owned by the Jito Tip Distribution Program.
- total_tips: The total amount of tips in the TipDistributionAccount
- validator_fee_bps: The validator's cut of tips from TipDistributionAccount, calculated from the on-chain commission fee bps.
delegations: Delegations to this validator.
- stake_account_pubkey: The public key of the stake account.
- staker_pubkey: The public key of the staker.
- withdrawer_pubkey: The public key authorized to withdraw from the stake account.
- lamports_delegated: Lamports delegated by the stake account
total_delegated: The total amount of delegations to the validator.
commission: The validator's delegation commission rate as a percentage between 0-100.

After each vote, consensus of node operators will be checked. After ⅔ of stake agrees on a merkle root for a given validator, a cross program invocation will take place to upload the merkle root to the validator’s tip distribution account.
Operators can change their vote until consensus is reached, then they can not change their vote. Once consensus is reached, any operators who have not voted have a fixed window of slots to submit their vote in order to be eligible for rewards.