Write your app once, against one API, and it runs on every chain XChain supports: Bitcoin, Litecoin, and Dogecoin today, each chain added under the protocol tomorrow. Behind that API sit a sandboxed contract VM, a staked validator network, a versioned command set for every operation the protocol supports, and an SDK that turns all of it into a few function calls. You do not run a new chain, you do not trust a bridge, and you never write per-chain code.
Smart contracts
XChain runs a real, sandboxed JavaScript VM on the base chain itself: deterministic, reorg-safe, and with a safety model fundamentally different from the EVM.
Orchestration, not mutation
On most platforms the contract is the protocol: it reads and writes state directly, so a single bug can mint tokens or drain balances. XChain separates the two. A contract can't credit a balance or move a token; it emits the platform's own validated ACTIONs (SEND, MINT, ORDER, DISPENSER…), and the same battle-tested handlers that check every user transaction also bound every contract.
The payoff: a contract bug can fail; it can't break the protocol, drain the ledger, or mint from thin air. The audit surface stays small, and an improvement to any handler benefits every contract automatically.
Exact decimal math, never floating point, so balances can't drift or round wrong, even at 18 decimals. Sandboxed V8 isolates strip every non-deterministic API and gas metering bounds each run, so every node replays to the identical result and state is reorg-safe.
Read balances, token info, oracle prices, and cross-chain attestations; keep persistent key-value state; emit 19 action types; and do exact math up to sqrt, pow, and log.
Ask an HTTPS endpoint or an AI model a question and get a validator-verified answer back through an async callback, powered by the validator network below.
Any contract can declare itself stakeable: lock any token, on any supported chain, against it, and let its code decide what that unlocks, with a cooldown and slash rule fixed at deploy time and never changeable.
Smart contracts → Token rules & royalties → The VM component →
Decentralized infrastructure
XChain is more than an indexer. A network of staked validators runs a decentralized oracle, attests cross-chain trades, and governs the protocol, coordinating over PBFT consensus and signed peer-to-peer gossip, while never taking custody of your funds.
Validators pull prices from multiple sources, aggregate by trimmed median (top/bottom 15% discarded), and finalize each round through PBFT consensus, so network fees and fiat-priced tokens, dispensers, and orders all use one manipulation-resistant rate.
Before any cross-chain trade settles, validators that support both chains reach consensus that the source action is real and confirmed: 6 confirmations on Bitcoin, 12 on Litecoin, 60 on Dogecoin.
Validators stake to auto-qualify for four independent capabilities (price, cross-chain, oracle publishing, and attestation), earning rewards for honest work and risking slashing for misbehavior.
Protocol parameters change only through a transparent validator governance process: a 7-day voting period with 2/3 approval and quorum. No single party has unilateral control. Token holders get their own on-chain say too, through the VOTE action.
The validator network → State checkpoints → The hub component →
Every operation on XChain, from issuing a token to running a contract, is one of 36 versioned commands embedded in a transaction.
Architecture
Thirteen independent open-source components turn the chains you run into a programmable token economy, with every layer auditable and replaceable, each with its own page.
Reads blocks, validates ACTIONs, maintains token & contract state, and serves 50+ REST / JSON-RPC endpoints.
Builds PSBTs, tracks UTXOs, and exposes builders for most ACTIONs plus 100+ queries through the developer SDK.
The validator network (oracle, attestation, SWAPs, governance) and the sandboxed smart-contract engine.
Trust-minimized replication, the reference wallet, one-command deployment, and the full regtest test stack.
Quality
XChain handles real value, so it's verified like it. Over 31,000+ automated tests across 13 disciplines (unit, integration, end-to-end, fuzz, security, chaos, mutation, determinism, and more) guard every component that touches token data.
Where to go next
Three readers land here: people writing an integration, people evaluating the protocol, and people who want to run it. Start where you actually are.
Balances, encoding, signing, broadcasting, streaming, and cross-chain coordination, in a few calls. The thing you actually build against.
Every protocol command, what it does, and what you can build with it. The vocabulary underneath the SDK.
All 13 services, what each one owns, and where it sits in the data pipeline.
One-command install, self-hosting, and how to verify the platform's state yourself rather than trusting ours.
How the platform is tested, discipline by discipline, with the evidence.
The full reference: 200+ pages of protocol spec, per-component detail, and a 17-page tutorial track.