Raise BALANCE_PER_ADDITIONAL_CUSTODY_GROUP from 32 ETH to 256 ETH, increasing the total effective balance that requires a validating node to custody all 128 groups from 4,096 ETH to 32,768 ETH.
The existing 4,096 ETH threshold can impose full custody on home operators with delegated stake, for example through Lido CSM or Rocket Pool. High-bandwidth residential connections may be unavailable locally even when an operator can afford better hardware. As blob throughput grows, this requirement risks reducing geographic diversity, as well as becoming a further constraint on blob scaling. Raising the threshold allows more home operators to benefit from partial custody as blob throughput increases.
The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119 and RFC 8174.
Set BALANCE_PER_ADDITIONAL_CUSTODY_GROUP to 256 ETH:
| Name | Type | Value |
|---|---|---|
BALANCE_PER_ADDITIONAL_CUSTODY_GROUP |
Gwei |
Gwei(256 * 10**9) |
The following parameters are unchanged:
| Name | Mainnet value |
|---|---|
NUMBER_OF_CUSTODY_GROUPS |
128 |
SAMPLES_PER_SLOT |
8 |
CUSTODY_REQUIREMENT |
4 |
VALIDATOR_CUSTODY_REQUIREMENT |
8 |
The custody formula is unchanged. For total effective balance B in ETH, taken from the latest finalized state across all validators attached to the node, the required group count is:
min(max(floor(B / 256), 8), 128)
The requirement first exceeds eight groups at 2,304 ETH and reaches all 128 groups at 32,768 ETH. Operators MAY custody more than the required count.
The existing retention rule is unchanged: when a requirement decreases, a node SHOULD continue to custody, advertise, and serve its previous highest custody_group_count, persisting that count across restarts.
The baseline for this EIP is the PeerDAS validator custody specification and networking specification.
The 256 ETH increment is chosen to substantially reduce the custody burden on operators with delegated stake: at 4,096 ETH, the requirement falls from 128 groups to 16. The reconstruction capacity retained at the resulting full-custody threshold is assessed in Security Considerations.