Immune Owner Uids Limit
Immune owner uids limit is a per-subnet hyperparameter, listed in the documentation as
ImmuneOwnerUidsLimit, that caps how many neurons on a subnet may be marked as owner-immune. The
reference describes it as determining the maximum number of neurons that can be marked owner-immune
on a subnet, with a default of one
(Subnet Hyperparameters).
What It Controls
The hyperparameter sets a count ceiling, not which specific UIDs receive immunity or how long ordinary immunity period protection lasts after registration. It limits how many neurons the subnet owner can designate as owner-immune at once (Subnet Hyperparameters, Glossary: Immunity Period).
Owner-immune status is separate from the post-registration immunity window that shields new entrants from deregistration. The limit governs how many standing neurons may carry the owner-immune label, which affects how many slots the owner can shield from ordinary competitive displacement rules on that netuid (Subnet Hyperparameters).
The cap is owner-tunable per subnet, so netuid 1 can use the default while another netuid allows a higher owner-immune count, and the live value is chain state rather than a network constant (Subnet Hyperparameters, Bittensor Networks).
Effect on Pruning
Owner-immune neurons are skipped entirely when a full subnet selects a UID to replace on
registration. Unlike ordinary post-registration immunity, which can still be pruned as a fallback
when too few non-immune UIDs remain, an owner-immune hotkey is never chosen for displacement, so
this limit caps how many slots stay permanently outside the replacement pool
(get_neuron_to_prune).
There is also a network-level cap on total immune share in the trimming path. The UID-trimming
documentation states that the maximum number of immune UIDs must not exceed 80% of the maximum UID
count, and the constants reference exposes that ceiling as
api.consts.subtensorModule.maxImmuneUidsPercentage with value 80. That percentage cap bounds the
combined immune portion of the table, while ImmuneOwnerUidsLimit is the per-subnet count cap for
owner-immune designations (UID Trimming,
Subtensor Constants: maxImmuneUidsPercentage).
Documented Type and Default
The Subnet Hyperparameters
reference lists ImmuneOwnerUidsLimit as a u16 with a default of one and marks the permission
required to change it as subnet owner
(Subnet Hyperparameters).
Because each subnet carries its own hyperparameters, the owner-immune cap on one netuid can differ from the documented default and from the cap on another subnet (Subnet Hyperparameters).
Reading the Live Value for netuid 1
Immune owner uids limit is per-subnet chain state, so any live claim is tied to a specific netuid. For the documented example netuid 1 on Finney mainnet, the limit appears in that subnet’s hyperparameter table, which the reference describes under viewing a subnet’s hyperparameters (Subnet Hyperparameters: View hyperparameters). The infobox uses netuid 1 only as an example label; other subnets expose their own values (Bittensor Networks).
Distinction from Immunity Period
Immunity period is the block-counted window after registration when a new neuron is protected from deregistration. Immune owner uids limit is the separate cap on how many neurons may be marked owner-immune regardless of registration timing (Subnet Hyperparameters, Glossary: Immunity Period).
- Immunity period — post-registration protection window for new entrants.
- Immune owner uids limit — maximum count of owner-immune neurons on a subnet.