Cordapp

Cordapp, short for Corda Distributed Application, is the unit of deployment on the Corda blockchain platform. CorDapps implement the business logic and data models that allow a Corda network to support a specific set of processes, such as asset transfer, trade finance, or identity workflows. A CorDapp runs on Corda nodes and its components communicate through multi-party flows while enforcing contract constraints on the ledgers.

A CorDapp typically comprises contracts, states, and flows. Contracts encode the rules that govern state transitions and contain a verify function to enforce constraints. States define the data carried by the ledger for a given contract. Flows coordinate the interaction among participants to negotiate and finalize transactions, including collecting signatures, notarization, and recording the transaction.

CorDapps are written in Java or Kotlin and packaged as a CorDapp JAR for deployment on Corda nodes. They declare the set of contracts and flows they contain and are typically organized into modules such as a contracts module and a flows module. Deployment on a network may require compatibility with node versions and governance policies; contract upgrades allow moving to new contract versions under established rules.

Operated in a permissioned network, CorDapps preserve privacy by restricting data visibility to involved parties. They work with notaries and the network map to ensure the uniqueness and finality of transactions. Common use cases include trade finance, asset tracking, and inter-organizational lending.