What's new in 0.8.0

Preview features: available in the latest preview. APIs may change before the stable release.

The 0.8.0 previews add several major features for building Cardano applications in Java. For the complete list of changes, see the release notes.

New features

Unified Tx API

ScriptTx is deprecated in the 0.8.0 previews (not in stable 0.7.x). All script operations, such as collectFrom with redeemers, Plutus minting, validator attachment, and script-protected staking and governance, are available directly on the Tx class. You no longer choose between Tx and ScriptTx, and you can mix script and non-script operations in one transaction.

TxFlow: multi-step transactions

TxFlow orchestrates multi-step Cardano transactions with automatic UTXO chaining, confirmation tracking, rollback detection and retries.

TxStream: many transactions, reliably

TxStream submits a continuous stream of transactions, each landing once, and durable stores carry that across restarts. It runs on the TxFlow engine, and it’s experimental: see known issues.

TxPlan: YAML transactions

TxPlan defines Cardano transactions in YAML, with variables and context properties, and runs them through QuickTxBuilder. It’s part of the quicktx module, so it needs no additional dependency.

Verified data structures

Merkle Patricia Forestry (MPF) and Jellyfish Merkle Tree (JMT), with RocksDB and SQL storage. MPF proofs can be verified on chain by Aiken’s library.

New in 0.8.0-pre7

CIP-113 programmable tokens: tokens with on-chain transfer rules, through the new cardano-client-programmable-token module.
QuickTx extensions in TxFlow: TxFlow and TxStream can run steps that use extension intents, such as programmable tokens.
MPF proofs: proofs are now canonical and match the official JavaScript library. RocksDB garbage collection also received data-loss fixes. See MpfTrie.
JMT: absence proof fixes, bounded historical reads and a schema installer. See Jellyfish Merkle Tree.
Nexus backend: the new cardano-client-backend-nexus module.
TxPlan: the additional_signers_count context property.
Lower-level parsing: stack-safe CBOR and Plutus data codecs, plus RawTx and RawBlock views that keep a transaction’s original bytes.
GraalVM: reachability metadata now ships in the module jars.

Gradle dependencies

def cclVersion = '<version>' // the latest preview

dependencies {
    // Core library, including QuickTx with the Unified Tx API and TxPlan
    implementation "com.bloxbean.cardano:cardano-client-lib:$cclVersion"

    // TxFlow and TxStream
    implementation "com.bloxbean.cardano:cardano-client-txflow:$cclVersion"

    // Verified data structures on RocksDB
    implementation "com.bloxbean.cardano:cardano-client-merkle-patricia-forestry-rocksdb:$cclVersion"
    implementation "com.bloxbean.cardano:cardano-client-jellyfish-merkle-rocksdb:$cclVersion"

    // Backend provider (choose one)
    implementation "com.bloxbean.cardano:cardano-client-backend-blockfrost:$cclVersion"
}

API stability

See known issues for current gaps. These APIs are a preview for early adopters. Core concepts are stable, but method signatures, configuration options and defaults may change before the stable release.

If you find a problem or have a suggestion, please open an issue on GitHub.