XChain's core idea is to stop making one chain do everything. Split the world in two, and join the halves with a single principle — verify, don't re-execute.

Base A is where value and atomicity live: consensus chains that hold assets, payments, identity, and anything that needs double-spend protection.
Base B is where the ocean lives: a vast, verifiable data fabric of append-only logs, with no per-log consensus, for the high-volume low-value data that would drown a normal chain.

The upper layers never re-run what the lower layers did — they check a proof that it was done correctly. That one move is what makes planetary scale thinkable.

Six principles carry the whole design:

#	Principle	What it means
1	Aggregate, not global	Big capacity is aggregate throughput, never one synchronous global state.
2	Locality-first	Over 99% of activity should stay local; putting state in the right place is job one.
3	Assurance ∝ value	A transaction's security, data availability and proof scale with what it's worth.
4	Verify, don't re-execute	The layer above checks an aggregated proof instead of re-running the work.
5	A narrow waist	The core stays small and hard-defined; the space to build above it is unbounded.
6	Prune by default	Low-value data expires; only the commitment is forever; every chain pays its own way.

The elegant part: every one of these six exists so that most of the world's volume can travel a near-free path, while value and atomicity concentrate in the small, most-protected core. Scale and safety stop fighting each other.