What is Chaincode?¶
Chaincode is a program, written in Go, node.js, and eventually in other programming languages such as Java, that implements a prescribed interface. Chaincode runs in a secured Docker container isolated from the endorsing peer process. Chaincode initializes and manages ledger state through transactions submitted by applications.
A chaincode typically handles business logic agreed to by members of the network, so it may be considered as a “smart contract”. State created by a chaincode is scoped exclusively to that chaincode and can’t be accessed directly by another chaincode. However, within the same network, given the appropriate permission a chaincode may invoke another chaincode to access its state.
We offer two different perspectives on chaincode. One, from the perspective of an application developer developing a blockchain application/solution entitled Chaincode for Developers, and the other, Chaincode for Operators oriented to the blockchain network operator who is responsible for managing a blockchain network, and who would leverage the Hyperledger Fabric API to install, instantiate, and upgrade chaincode, but would likely not be involved in the development of a chaincode application.