Nexus tokenomics

This non-normative note summarizes the configured economics of Nexus, Lattice’s single outermost chain. The concrete configuration lives in NexusGenesis.swift. Lattice interprets it using ChainSpec.swift and the generic economic rules.

Do not copy a premine recipient, timestamp, or genesis CID from this page. Those identity-bearing values have one canonical home in NexusGenesis.swift.

Design Intent

Nexus favors a light, long-lived root:

• one-hour blocks and one-megabyte block bodies limit payload growth;
• bounded state growth limits each transition’s expansion;
• a long issuance schedule keeps subsidy available over a long horizon;
• applications needing different capacity or cadence can use child chains.

A child receives only path-bound verified work that actually covers it. It does not automatically inherit all Nexus hashpower or Nexus canonicity.

Configured Parameters

Parameter	Value	Meaning
initialReward	1,048,576	Initial subsidy, 2^20
halvingInterval	876,600 blocks	About 100 years at one-hour blocks
premine	175,320 blocks	Front-of-schedule issuance
targetBlockTime	3,600,000 ms	One hour
halfLife	120 blocks	The schedule’s half-life, about five days
maxBlockSize	1,000,000 bytes	Unique canonical block + transaction Volume bytes
maxStateGrowth	3,000,000 bytes	Per block
maxNumberOfTransactionsPerBlock	5,000	Per block

There is no per-retarget clamp and no minimum-target floor: the schedule is absolute. A chain directory is positional path data, not a ChainSpec field.

Emission

The public block subsidy is

rewardAtBlock(height)
    = initialReward >> ((height + premine) / halvingInterval)

premine advances public mining along the same reward curve. For Nexus, the first public halving is therefore

876,600 - 175,320 = 701,280 blocks

or about 80 years at the target cadence. Later halvings remain 876,600 blocks apart. Integer shifts eventually reduce the reward to zero; there is no tail emission.

The implementation returns zero instead of trapping if height + premine overflows or the shift reaches 64 bits.

Premine

Because the Nexus premine is shorter than one halving interval, every premined block uses the initial reward:

premineAmount
    = 175,320 * 1,048,576
    = 183,836,344,320

The recipient and exact genesis transaction are fixed by NexusGenesis.swift. Generic genesis validation permits total credits up to the configured premineAmount; it does not infer a recipient.

Supply

The geometric closed-form limit is

2 * halvingInterval * initialReward
    = 1,838,363,443,200

The exact integer-terminated schedule is

halvingInterval * (2^21 - 1)
    = 1,838,362,566,600

The premine is exactly 10% of the closed-form limit and approximately 10% of the exact integer-terminated supply. The small difference is the finite tail removed by integer halving.

Cadence And Fees

Nexus retargets every block by an absolute schedule (ASERT) measured from the height-1 anchor of the block’s own branch, not by a window over recent intervals. A block’s target is its parent’s nextTarget or voluntarily harder, never easier — there is no minimum-target floor and no recovery exception.

The schedule holds difficulty steady at exactly one-hour spacing, and moves one doubling per half-life of accumulated drift, where the half-life is halfLife × targetBlockTime = 120 hours. Because the target depends only on the anchor and the present block, a stretch of unusual block times stops mattering the moment it stops happening — there is no window to drain and no clustered-window attractor to walk back out of. Moving a timestamp backwards hardens rather than eases, and moving it forwards is capped by the validating node’s clock and eases only the single successor without compounding. See specification §5.5.

The signed fee field does not automatically move value. Lattice enforces the block-wide non-creation bound over explicit actions. A node may require an explicit payer debit and construct an author credit as fee policy. See Fee Policy And Majority-Reorg Cost.

Sources

Fact	Canonical home
Nexus parameters and genesis identity	lattice-node/Sources/LatticeNode/Architecture/NexusGenesis.swift
Reward and premine arithmetic	Sources/LatticePrimitives/Block/ChainSpec.swift
Generic consensus rules	Protocol specification
Adversarial fork-choice model	Consensus simulator

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Source: Lattice/docs/economics/nexus-tokenomics.md at 54.2.1