# max_validators (/docs/hyperparameters/max-validators) `max_validators` caps how many neurons on a subnet hold a validator permit at once. Anyone deciding whether their stake is enough to validate on a subnet needs this number: without a permit, a neuron's weights are ignored and it earns no dividends. ## How it works [#how-it-works] Every epoch recomputes permits from scratch (`pallets/subtensor/src/epoch/run_epoch.rs`): `is_topk_nonzero(&stake, k)` with `k = MaxAllowedValidators` grants permits to the top-`k` neurons by stake weight (alpha stake plus TAO stake scaled by `tao_weight`), skipping zero-stake neurons; the subnet owner's UID is always permitted. The mainnet default is 128, and the value must not exceed `max_allowed_uids`. Losing a permit is immediate and total: non-permitted validators' stake is masked from the active-stake vector, their weight rows are discarded before consensus, and their accumulated bonds are cleared — so a validator that slips out of the top-`k` re-enters later with no bond history. Permits interact with [`activity_cutoff`](/docs/hyperparameters/activity-cutoff): holding a permit is necessary but not sufficient, since an inactive permitted validator is also excluded. See [Yuma Consensus](/docs/concepts/emissions#yuma-consensus) for where permits sit in the pipeline. The chart below sorts neurons by stake and draws the permit line at the top-`max_validators` — slide the cap to move it. ## Reading and setting [#reading-and-setting] Inspect with: ``` btcli sudo get --netuid N --name max_validators ``` Not settable by the subnet owner — root/governance only (`sudo_set_max_allowed_validators` in AdminUtils requires the root origin and enforces the `max_allowed_uids` ceiling). The value is a plain integer. ## Related [#related] [`rho`](/docs/hyperparameters/rho) · [`kappa`](/docs/hyperparameters/kappa) · [`tempo`](/docs/hyperparameters/tempo) · [`activity_cutoff`](/docs/hyperparameters/activity-cutoff) · [`max_allowed_uids`](/docs/hyperparameters/max-allowed-uids)