SNS settings

Each SNS is customized through its nervous system parameters, also called SNS settings. These parameters govern voting power calculation, governance rules, asset economics, and reward behavior. Parameters are set at launch and can be changed by governance proposal at any time.

For background, see SNS framework.

Neuron settings

Parameter	Type	Description
neuron_minimum_stake_e8s	nat64	Minimum number of e8s (10⁻⁸ of the SNS asset) that can be staked in a neuron. Must be larger than transaction_fee_e8s.
max_number_of_neurons	nat64	Maximum number of neurons allowed. New neurons are blocked once this ceiling is reached. Ceiling: 200,000.
max_number_of_principals_per_neuron	nat64	Maximum number of principals that can hold permissions for a single neuron.
neuron_claimer_permissions	permission set	The set of permissions automatically granted to the principal that claims a new neuron.
neuron_grantable_permissions	permission set	The superset of permissions that a principal with ManagePrincipals permission can grant to others on the same neuron.
default_followees	map	Default following rules applied to every newly created neuron, as a mapping of proposal function IDs to followee neuron IDs.
max_followees_per_function	nat64	Maximum number of followees a neuron can configure per proposal function. Ceiling: 15.

Voting power settings

Parameter	Type	Description
neuron_minimum_dissolve_delay_to_vote_seconds	nat64	Minimum dissolve delay a neuron must have to be eligible to vote. Must be less than max_dissolve_delay_seconds.
max_dissolve_delay_seconds	nat64	Maximum dissolve delay achievable by a neuron. The dissolve delay bonus is saturated at this value.
max_dissolve_delay_bonus_percentage	nat64	Additional voting power percentage granted at maximum dissolve delay. Set to 100 for a 2x bonus (matching Network Nervous System (NNS) behavior). Set to 0 for no bonus.
max_neuron_age_for_age_bonus	nat64	Maximum neuron age (seconds) at which the age bonus is saturated.
max_age_bonus_percentage	nat64	Additional voting power percentage granted at maximum age. Set to 25 for a 1.25x bonus (matching NNS behavior). Set to 0 for no bonus.

Proposal and governance settings

Parameter	Type	Description
reject_cost_e8s	nat64	Fee (in e8s) charged to the proposer when a proposal is rejected, to discourage spam.
initial_voting_period_seconds	nat64	Initial voting period for non-critical proposals. The actual period may be extended by wait-for-quiet. Does not affect existing proposals.
wait_for_quiet_deadline_increase_seconds	nat64	Maximum total extension added by wait-for-quiet when a proposal outcome flips. The voting period can increase by at most twice this value. Does not affect existing proposals.
max_proposals_to_keep_per_action	nat64	Maximum number of proposals retained per proposal type. When exceeded, the oldest finalized proposals are eligible for deletion. Ceiling: 700.
max_number_of_proposals_with_ballots	nat64	Maximum number of open (unsettled) proposals with stored ballots. When reached, only a few critical proposal types can still be submitted. Ceiling: 700.

Digital asset and fee settings

Parameter	Type	Description
transaction_fee_e8s	nat64	Per-transfer fee on the SNS ledger, in e8s. Does not apply to minting or burning.

Voting reward settings

All reward settings live inside a single nested field: voting_rewards_parameters. If this field is absent, voting rewards are disabled.

Parameter	Full field name	Description
round duration	round_duration_seconds	Length of a single reward distribution round, in seconds. Rewards are distributed to voting neurons at the end of each round. Default: 86,400 (1 day).
r_max	initial_reward_rate_basis_points	Starting annualized reward rate as a fraction of total supply, in basis points (100 = 1%).
r_min	final_reward_rate_basis_points	Floor reward rate after the transition period, in basis points. Set to 0 to end issuance after t_delta.
t_delta	reward_rate_transition_duration_seconds	Duration of the quadratic decline from r_max to r_min, in seconds.
t_start	start_timestamp_seconds	Timestamp (Unix seconds) when reward accrual begins. Set automatically to the current time when rewards are first enabled.

Maturity modulation

Parameter	Type	Description
maturity_modulation_disabled	opt bool	If true, maturity modulation is disabled for this SNS: the ±5% conversion randomness is not applied when neuron holders disburse maturity. The CMC is still polled but the fetched value is ignored. Default: false (modulation enabled).

SNS framework upgrade

Parameter	Type	Description
automatically_advance_target_version	opt bool	If true, the SNS automatically upgrades to the latest NNS-approved SNS version without a governance proposal. Defaults to true for newly created SNSs, false for older ones.