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yanox BUILD SHARED TRUST

eUTxO ledger

A deterministic, Cardano-shaped eUTxO state machine that runs as an app ledger capability, with an optional Cardano bridge on top.

Problem

Section titled “Problem”

Teams want to run Conway-shaped transactions at application-ledger speed and cost, with threshold finality and proofs, and later move value between that ledger and Cardano. Building a UTxO engine and a bridge from scratch is a large, risky undertaking.

Who it is for

Section titled “Who it is for”
  • Researchers and protocol teams exploring eUTxO execution on an app ledger or a federated bridge.
  • Developers who want a disposable, no-real-funds environment for Cardano-shaped transactions.

It is not for production value, custody, or public bridges.

Actors and flow

Section titled “Actors and flow”

The bridge is an optional layer on top of the ledger:

The eUTxO layersConcept
APP LEDGER · EUTXO STATE MACHINEeUTxO ledgereutxo-ledger recipeCardano bridgeeutxo-cardano-bridgeCardanodevnet or testnetdeposits, withdrawalsAPP LEDGER · EUTXO STATE MACHINEeUTxO ledgereutxo-ledger recipeCardano bridgeeutxo-cardano-bridgeCardanodevnet or testnet
  • App ledger · eUTxO state machine: eUTxO ledger, Cardano bridge.
  • eUTxO ledger → Cardano bridge.
  • Cardano bridge → Cardano (deposits, withdrawals).
eUTxO ledger
The reusable state:eutxo-ledger engine: deterministic Cardano-shaped UTxO state, root-fixed receipts, and MPF-proven outputs under one immutable ledger profile. The eutxo-ledger recipe adds profile:eutxo-plutus-v3 and a virtual genesis allocation (funding:eutxo-genesis) for no-real-funds testing. Availability FIRST_PARTY_OPTIONAL, maturity experimental.
Cardano bridge
bridge:cardano-federated observes accepted deposits to a Cardano vault and settles bounded claims. It needs l1:slot-feed and replaces the virtual genesis allocation: the two conflict. Availability EXPERIMENTAL.
Cardano
The bridge deposits to and withdraws from Cardano. Use a devnet or a Cardano test network with disposable keys.
The Cardano bridge is an optional layer on the deterministic eUTxO ledger. Both are experimental, and neither is for real funds.
  • capability layer
  • Cardano
RecipeAvailabilityWhat it adds
eutxo-ledgerFIRST_PARTY_OPTIONALThe deterministic UTxO ledger with a virtual genesis allocation.
eutxo-cardano-bridgeEXPERIMENTALFederated deposit and withdrawal against Cardano.

The eutxo-ledger recipe combines the reusable state:eutxo-ledger engine with profile:eutxo-plutus-v3 and the separate funding:eutxo-genesis capability:

yano:
  app-chain:
    chains:
      - chain-id: payments-eutxo
        state-machine: eutxo-ledger
        machines:
          eutxo:
            profile: yano-eutxo-v2-plutus-v3
            expected-profile-digest: 8cd4adb72def2c31dc8551a02f67429ea468bb2024dbe85a1dc7300590c9d1bf
            genesis:
              address: addr_test1...
              lovelace: 100000000

The profile commitment is SHA-256 over its canonical, versioned consensus fields. All members must use the same profile, digest, and genesis allocation: this is part of the ledger’s identity, not a tunable. Exactly one immutable ledger profile owns the consensus settings at a time.

What it proves, and what it does not

Section titled “What it proves, and what it does not”

The ledger proves what any app ledger proves: that a threshold of members finalized each transaction in order, and that each output is in the state under a certified root, with an MPF proof.

It does not make the bridge trustless. The bridge is federated custody: in signer mode it trusts an external threshold or HSM, and in proof mode it trusts the threshold-accepted root. Nothing here is ready for production value.

The lifecycle indexer is a rebuildable read index. It lives in appchain-indexers/, never takes part in validation, roots, finality, or settlement, and must never be treated as authoritative state. See Where data lives.

Try it

Section titled “Try it”

The disposable demos create three-node devnet clusters with local test identities. From the root of an extracted yano-x-jvm-<version>.zip, beside yano.sh:

Terminal window
./yano.sh appchain eutxo demo scenarios
./yano.sh appchain eutxo demo up --scenario ledger --workspace ./eutxo-ledger-demo
./yano.sh appchain eutxo demo round-trip --workspace ./eutxo-ledger-demo
# Expected: EUTXO_LEDGER_DEMO_ROUND_TRIP_PASS

The bridge scenario follows the same pattern. The demo guide covers both.

Modules

Section titled “Modules”
GoalGuide
The eUTxO family overviewledgers/eutxo/README.md
Indexer API, SQLite, recovery, metricsIndexer operations

The modules live under ledgers/eutxo, and the lifecycle console ships as product-ui/eutxo.

Status

Section titled “Status”

experimental. Production release is gated on the audit and operational gates described in the eUTxO ADRs.