Runtime identity vs tree address

Definition

A runtime identity is the stable node identity the runtime tracks across structural edits.

A tree address is the current structural location of a node in the document tree.

In Slate terms:

• runtime identity: RuntimeId
• tree address: Path

Why the split matters

Tree addresses are excellent for transforms and structural queries.

They are bad public identity contracts for live overlay UI because they move when structure moves.

Strongest supporting evidence

• local Slate v2 snapshot indexes expose both idToPath and pathToId
• local Slate v2 tests prove runtime ids survive important structural edits
• VS Code and ProseMirror both anchor public visual systems by ranges/ids, not tree-path APIs

Practical use

This concept is the reason the Slate v2 plan cut public path-based widget anchors.