A two-base meta-blockchain for inclusive, verifiable data at scale. Public good, open source (Apache-2.0). Live explorer: www.xscan.org — real testnet height, validators, and transactions. This documentation follows one rule the project itself lives by: tell the truth about what is solid and what is still hard. Where something is a work in progress, it says so.

Overview

XChain is an open, two-base meta-blockchain — a foundation layer that thousands of applications and chains can build on, rather than "a faster blockchain." It is a public good, open source under Apache-2.0, and it runs on a live public testnet today (early phase — "Testnet MVC").

The whole system is organized by one principle: verify, don't re-execute. It splits into two bases stacked on top of each other:

	Base A — Secured Execution	Base B — Verifiable Data Fabric
Nature	Consensus chains (Cosmos SDK + CometBFT + IBC)	Namespaced append-only logs on a Data Availability layer (no per-log consensus)
Tiers	T0–T2	T3–T4
Holds	Value, assets, identity, atomicity	Likes, views, chat, IoT, logs (high-volume, low-value)
Testnet	3 chains: `a0-root` · `a1-value` · `a2-interactive`	9 namespaces on one DA node (Celestia)

Connecting the two is a narrow waist of seven core primitives, hard-specified so many teams can build in parallel and still compose — and so the community can build without asking permission from the core.

Diagram

In one line: XChain is ambitious enough to be worth building and honest enough to be worth trusting — the honesty is a feature, because real builders are drawn to hard, unsolved problems, not to promises that everything is already done.