corda/docs/source/release-notes.rst

Release notes

Here are brief summaries of what's changed between each snapshot release.

Unreleased

• Smart contracts have been redesigned around reusable components, referred to as "clauses". The cash, commercial paper and obligation contracts now share a common issue clause.

Milestone 1

Highlights of this release:

• Event scheduling. States in the ledger can now request protocols to be invoked at particular times, for states considered relevant by the wallet.

• Upgrades to the notary/consensus service support:

  • There is now a way to change the notary controlling a state.
  • You can pick between validating and non-validating notaries, these let you select your privacy/robustness tradeoff.

• A new obligation contract that supports bilateral and multilateral netting of obligations, default tracking and more.

• Improvements to the financial type system, with core classes and contracts made more generic.

• Switch to a better digital signature algorithm: ed25519 instead of the previous JDK default of secp256r1.

• A new integration test suite.

• A new Java unit testing DSL for contracts, similar in spirit to the one already developed for Kotlin users (which depended on Kotlin specific features).

• An experimental module, where developers who want to work with the latest Corda code can check in contracts/cordapp code before it's been fully reviewed. Code in this module has compiler warnings suppressed but we will still make sure it compiles across refactorings.

• Persistence improvements: transaction data is now stored to disk and automatic protocol resume is now implemented.

• Many smaller bug fixes, cleanups and improvements.

We have new documentation on:

• event-scheduling
• transaction-data-types
• consensus

Summary of API changes (not exhaustive):

• Notary/consensus service:

  • NotaryService is now extensible.
  • Every ContractState now has to specify a participants field, which is a list of parties that are able to consume this state in a valid transaction. This is used for e.g. making sure all relevant parties obtain the updated state when changing a notary.
  • Introduced TransactionState, which wraps ContractState, and is used when defining a transaction output. The notary field is moved from ContractState into TransactionState.
  • Every transaction now has a type field, which specifies custom build & validation rules for that transaction type. Currently two types are supported: General (runs the default build and validation logic) and NotaryChange ( contract code is not run during validation, checks that the notary field is the only difference between the inputs and outputs). TransactionBuilder() is now abstract, you should use TransactionType.General.Builder() for building transactions.

• The cash contract has moved from com.r3corda.contracts to com.r3corda.contracts.cash

• Amount class is now generic, to support non-currency types such as physical assets. Where you previously had just Amount, you should now use Amount<Currency>.

• Refactored the Cash contract to have a new FungibleAsset superclass, to model all countable assets that can be merged and split (currency, barrels of oil, etc.)

• Messaging:

  • addMessageHandler now has a different signature as part of error handling changes.
  • If you want to return nothing to a protocol, use Ack instead of Unit from now on.

• In the IRS contract, dateOffset is now an integer instead of an enum.

• In contracts, you now use tx.getInputs and tx.getOutputs instead of getInStates and getOutStates. This is just a renaming.

• A new NonEmptySet type has been added for cases where you wish to express that you have a collection of unique objects which cannot be empty.

• Please use the global newSecureRandom() function rather than instantiating your own SecureRandom's from now on, as the custom function forces the use of non-blocking random drivers on Linux.

Milestone 0

This is the first release, which includes:

• Some initial smart contracts: cash, commercial paper, interest rate swaps
• An interest rate oracle
• The first version of the protocol/orchestration framework
• Some initial support for pluggable consensus mechanisms
• Tutorials and documentation explaining how it works
• Much more ...