A smart contract is code, invoked by a client application external to the blockchain network – that manages access and modifications to a set of key-value pairs in the World State. In Hyperledger Fabric, smart contracts are referred to as chaincode.
CCKit is a programming toolkit for
- developing and testing Hyperledger Fabric golang chaincodes
- generating access layer for query / invoke chaincodes and chaincode event streaming
It enhances the development experience while providing developers components for creating more readable and secure smart contracts. Getting started
- Chaincode method router with invocation handlers and middleware capabilities
- Chaincode state modeling (like ORM for chaincode data) using protocol buffers or plain golang struct with private data support
- Chaincode state serializing customization
- Designing chaincode in gRPC service notation with code generation of chaincode SDK, gRPC and REST-API
- MockStub testing, allowing to immediately receive test results
- Encryption data on application level
- Implementation of UTXO and account balance storage model token balance models
- Chaincode method access control
- Signing and verifying chaincode method payload with envelope
There are several chaincode "official" examples available:
- Commercial paper from official Hyperledger Fabric documentation
- Blockchain insurance application (testing tutorial: how to write tests for "insurance" chaincode)
and others
Main problems with existing examples are:
- Working with chaincode state at very low level
- Lots of code duplication (JSON marshalling / unmarshalling, validation, access control, etc)
- Chaincode methods routing appeared only in HLF 1.4 and only in Node.Js chaincode
- Uncompleted testing tools (MockStub)
- Cars - car registration chaincode, simplest example
- Commercial paper, service-oriented approach - recommended way to start new application. Code generation radically simplifies building on-chain and off-chain applications.
- Commercial paper - faithful reimplementation of the official example
- Commercial paper extended example - with protobuf chaincode state schema and other features
- ERC-20 - tokens smart contract, implementing ERC-20 interface
- ERC-20 UTXO - tokens smart contract, implementing ERC-20 interface with UTXO state keys
- Cars private - car registration chaincode with private data
- Payment - a few examples of chaincodes with encrypted state
- Service-oriented Hyperledger Fabric application development using gRPC definitions
- Hyperledger Fabric smart contract data model: protobuf to chaincode state mapping
- Hyperledger Fabric chaincode test driven development (TDD) with unit testing
- ERC20 token as Hyperledger Fabric Golang chaincode
- CCKit: Routing and middleware for Hyperledger Fabric Golang chaincode
- Developing and testing Hyperledger Fabric smart contracts [RUS]
CCKit requires Go 1.16+
git clone git@github.com:hyperledger-labs/cckit.git
go mod vendor
go get github.com/hyperledger-labs/cckit