Chain addressing

Rule

A chain’s public and internal identity is one absolute path from the single Nexus root. Every chain path includes Nexus as its first component.

Nexus
Nexus/Payments
Nexus/Payments/Rollups

Payments and Payments/Rollups are invalid even when sent to a host that serves Nexus. The Nexus component is never implicit. This keeps topology, transaction replay protection, wire routing, storage scopes, metrics, and API payloads on one representation.

Directory versus chain path

A directory is a single edge label chosen under an already known parent. It is intentionally parent-relative:

parent path:     Nexus/Games
child directory: Payments
child path:      Nexus/Games/Payments

The same directory may exist under another parent, so Payments is never a globally unique chain identity.

Term	Meaning
Nexus	The single root and first component of every path
Chain path	Complete absolute route beginning with Nexus
Chain address	Validated internal representation of a chain path
Directory	One direct parent-to-child edge label

Validation

ChainAddress accepts a component array or slash-separated string only when:

1. the first and exact root component is Nexus;
2. its child depth fits Lattice’s child-proof bound;
3. every component is 1–64 bytes of visible ASCII; and
4. no component contains Lattice’s directory separator.

ChainAddress delegates this grammar to ChainRuntimeContext, so node setup, transactions, state keys, and child proofs cannot drift. Process configuration also requires the complete canonical handshake to fit its wire frame.

Consequently, these are invalid:

Payments
/Nexus/Payments
Nexus/
Nexus//Payments
nexus/Payments

Where paths are load-bearing

• lattice.json.hostedChains lists the child paths one process serves, parent first; Nexus is implicit as the root.
• TransactionBody.chainPath is signed replay protection and must name a path hosted by the receiving process.
• The handshake pins Nexus and the protocol revision; routed sync frames carry their level’s full path on the one shared overlay.
• Mining reward routing uses full paths so each reward reaches one exact chain.
• Direct-child lookup uses the final directory only after the co-hosted parent relationship is established by the topology.
• Durable facts and cursors are keyed by full path, preventing leaf-name collisions inside the shared store.

Nexus root bootstrap

Nexus has no parent, so an empty store constructs the one pinned unsigned genesis locally before configured root bootstrap. It is never accepted from a peer. The path representation is not special-cased; Nexus is simply the valid one-component absolute path ["Nexus"].

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Source: lattice-node/docs/design/chain-addressing.md at 9abd15b1bb05