Block Reward Distribution to Stakers

This is how a Rakurai validator shares block rewards with their stakers. Solana has no native mechanism for it, so Rakurai adds an opt-in, Merkle proof-based flow powered by the Reward Distribution program.

You set a commission in basis points, keep that share of every block reward, and the remainder goes to stakers at the end of each epoch. Rakurai charges 0% for the distribution, and if you delegate Merkle root authority to Rakurai, the stake snapshot, tree build, root upload, and staker claims all run on your behalf.

This guide covers the full process — from enabling distribution on-chain to how rewards are accumulated, calculated, and claimed each epoch.

1. Background

1.1. No native protocol support

Solana's staking protocol distributes inflation / voting rewards to stakers automatically, but it provides no on-chain mechanism to distribute block rewards (the lamports earned during leader slots) to stakers. By default, block rewards remain in the validator identity account.

1.2. Rakurai's solution

Rakurai introduces an opt-in feature that lets any validator running Rakurai share block rewards with stakers. The flow is:

1. Configure how much of each block reward the validator retains (via the Rakurai Activation Account).
2. Accumulate the staker share on-chain in a per-epoch Reward Collection Account (RCA) throughout the epoch.
3. At epoch end, compute stake-weighted allocations off-chain (optionally adjusted via custom distribution config), upload a Merkle root on-chain, and execute staker claims. When Merkle root authority is delegated to Rakurai, Rakurai runs the full claim process on behalf of stakers.

1.3. Free for Rakurai validators

2. Configuration and flexibility

Distribution is controlled at two levels:

• On-chain (RAA) — Set a global block_reward_commission_bps to define what share of block rewards the validator keeps versus what goes to stakers. This is the only setting required to get started.
• Off-chain (optional) — Before each epoch ends, submit reward_distribution_config.json to fine-tune allocations when the Merkle tree is built. You can exclude stake accounts, set per-staker commission rates, redirect a staker's share to a referral claimant, or split the validator's retained rewards — without changing on-chain program logic.

With no off-chain config, rewards are distributed proportionally by stake at your on-chain commission rate. With a config file, you get full flexibility over who receives what before claims go live.

3. Default behavior (distribution disabled)

When a validator creates their Rakurai Activation Account (RAA), block_reward_commission_bps defaults to 10,000 bps (100%).

At 100%, the validator keeps all block rewards. Nothing is transferred to an RCA and no staker distribution occurs for that epoch.

4. Enable block reward distribution

To start sharing block rewards with stakers, set block_reward_commission_bps below 10,000 in your RAA.

4.1. Update commission via CLI

Use the Rakurai Activation CLI update-commission command:

rakurai-activation -p <PROGRAM_ID> update-commission \
  --block_reward_commission_bps <VALUE> \
  --identity_pubkey <IDENTITY_PUBKEY> \
  --keypair <IDENTITY_KEYPAIR> \
  --url <RPC_URL>

• Mainnet program ID: rAKACC6Qw8HYa87ntGPRbfYEMnK2D9JVLsmZaKPpMmi
• Testnet program ID: pmQHMpnpA534JmxEdwY3ADfwDBFmy5my3CeutHM2QTt

You can also set commission at RAA creation time with rakurai-activation init --block_reward_commission_bps <VALUE>. See the Activation CLI for details.

Verify your settings anytime with rakurai-activation show.

4.2. When the new commission takes effect

The updated commission applies:

• From the current epoch, if no RCA has been created for the current epoch yet.
• From the next epoch, if an RCA for the current epoch already exists.

4.3. Configure the Rakurai client (node operator)

The Rakurai Solana client must be configured with the correct CLI arguments so it can:

• Initialize the per-epoch RCA on your first leader turn.
• Transfer staker rewards into the RCA on every subsequent leader turn.
• Set reward_merkle_root_authority — the account allowed to upload the Merkle root after the epoch ends.

Set this authority to Rakurai for fully automated distribution, or keep it yourself if you prefer to run distribution manually.

5. Epoch lifecycle

Once commission is below 100%, the following happens every epoch. Full details are in the epoch flow.

1. RCA initialization — On the first leader turn, the Rakurai client creates a per-epoch Reward Collection Account (RCA).
2. Per-turn accumulation — On every leader turn, the staker share of the previous turn's block reward is transferred into the RCA; validator and block-builder commissions are retained separately. See per-turn transfers.
3. Post-epoch distribution — At the final slot, a stake snapshot is taken, a Merkle tree is built off-chain (allocations can be adjusted via custom distribution config), the root is uploaded on-chain, and staker claims are executed. When Merkle root authority is delegated to Rakurai, Rakurai runs the claim process on behalf of stakers. See post-epoch staker distribution.

When reward_merkle_root_authority is set to Rakurai, steps 1–3 are fully automated (0% distribution fee). See Reward Distribution — Free and Automated by Rakurai.

6. Customize distribution (optional)

Submit reward_distribution_config.json to the Rakurai team via Slack or Telegram before the epoch ends to fine-tune stake allocations. This optional file extends the on-chain settings from Configuration and flexibility.

6.1. Example configuration

{
  "validators_config": {
    "comment": "Validator-specific configuration keyed by vote account.",
    "<vote_account>": {
      "stakers": {
        "comment": "These `excluded_stake_pubkeys` stake accounts are excluded and will NOT receive rewards. All other stakers must receive at least the minimum block_reward_commission_bps specified on-chain. For example, if validator commission = 7000 BPS (70%), each staker must receive at least 30% of rewards.",
        "excluded_stake_pubkeys": [
          "<stake_account_1>",
          "<stake_account_2>"
        ],

        "custom_commissions": {
          "<stake_account_3>": {
            "commission_bps": 4000,
            "comment": "Validator gets 60%, staker gets 40%"
          },

          "<stake_account_4>": {
            "commission_bps": 5000,
            "referral_claimant_pubkey": "<referral_account>",
            "referral_claimant_commission_bps": 1000,
            "comment": "Validator gets 50%. From staker's 50%, 10% is redirected to referral claimant"
          }
        }
      },

      "validator_reward_split": {
        "claimant_pubkey": "<claimant>",
        "claimant_commission_bps": 5000,
        "comment": "validator rewards (if any): 50% to claimant, 50% to validator identity. If not specified, all remaining goes to validator identity."
      }
    }
  }
}

6.2. Configuration options

6.2.1. Exclude stake accounts

"excluded_stake_pubkeys": [
  "<stake_account>"
]

Excluded stake accounts receive no block rewards. You can effectively implement a whitelist by excluding every stake account except the ones you want to reward.

6.2.2. Custom stake account commissions

"custom_commissions": {
  "<stake_account>": {
    "commission_bps": 4000
  }
}

Overrides the validator's global commission for a single stake account. For example, if your global commission is 70%, you can give one staker 40% commission (60% to staker instead of 30%).

6.2.3. Referral reward sharing

"custom_commissions": {
  "<stake_account>": {
    "commission_bps": 5000,
    "referral_claimant_pubkey": "<referral_account>",
    "referral_claimant_commission_bps": 1000
  }
}

A portion of the staker's rewards is redirected to a referral claimant. In this example:

• Validator receives 50% (instead of 70%)
• Staker receives 40% (instead of 30%)
• Referral claimant receives 10%

6.2.4. Validator reward split

"validator_reward_split": {
  "claimant_pubkey": "<claimant>",
  "claimant_commission_bps": 5000
}

Splits the validator's retained rewards with another account. 5000 means 50% to the claimant and 50% to the validator identity.

6.3. What you can do with these options

• Share block rewards with all stakers proportionally.
• Effectively whitelist selected stake accounts.
• Exclude specific stake accounts.
• Offer preferential reward rates to selected stakers.
• Run referral reward programs.
• Split validator-retained rewards with another claimant.