web3cpp

Custom implementation of Web3 in C++.

This is NOT a 100% parity conversion of the web3js library, but rather a mix of web3js structure with some logic from the now deprecated aleth library from Ethereum.

See Differences from web3js for more details on how this project deviates from web3js.

Compiling

Dependencies

• CMake 3.19.0 or higher
• GCC with support for C++17 or higher
• Boost, libhidapi and OpenSSL
• (optional) Doxygen for generating the docs

Instructions

• Clone the project: git clone https://github.com/avme/web3cpp
• Go to the project's root folder, create a "build" folder and change to it: cd web3cpp && mkdir build && cd build
• Run cmake .. then cmake --build . -- -j$(nproc) inside the build folder
• If you want documentation, go back to the project's root folder and run doxygen Doxyfile from there
  • Docs will be generated at a folder named docs/html

CMake parameters

For use with cmake -D<param> ..:

• BUILD_STATIC (default ON) - compiles the library as static
• BUILD_TESTS (default ON) - compiles an extra program that runs some tests on the library

Differences from web3js

Due to architectural differences between JS and C++, most things were significantly changed. It's recommended to generate and read the docs from this project (see Instructions instead of following other implementations.

• web3.utils becomes namespace Utils
  • e.g. web3.utils.sha3("Hello!%") -> Utils::sha3("Hello!%")
• web3.eth.Contract becomes class Contract
  • e.g. var c = new web3.eth.Contract(...) -> Contract c(...)
• web3.eth.abi becomes namespace Solidity
  • e.g. web3.eth.abi.encodeParameters(['uint256','string'], ['2345675643', 'Hello!%']) -> Solidity::packMulti({{{"t", "uint256"}, {"v", "2345675643"}}, {{"t", "string"}, {"v", "Hello!%"}}}, err)
• The "network" part of web3.*.net is technically replaced by namespace Net (which does HTTP requests) and namespace RPC (which builds the data that is sent through the requests)
  • They're meant to be used together (e.g. Net::HTTPRequest(provider, Net::RequestTypes::POST, RPC::eth_getBlockNumber().dump()))
• The "node" part of web3.*.net is replaced by class Provider
• Parts of web3.eth.accounts and web3.eth.personal are joined in a custom Wallet class
• web3.eth becomes class Eth and almost all of its member variables were moved to Provider and/or Contract::Options
• You still access Provider, Wallet and Eth from inside the Web3 class
  • e.g. web3->getProvider()->getChainId(), web3->wallet.getAccounts(), web3->eth.getGasPrice()
• JavaScript's BN.js object is replaced by a simple unsigned 256-bit integer (aleth's dev::u256), which is aliased to BigNumber
• JSON objects are handled using nlohmann::json

Missing modules and functionalities

Some particular things are not (and probably won't be) implemented as we either don't have a need for them (at least for now) or other parts of the library are already doing their job.

• web3.bzz (Swarm Protocol)
• web3.shh (Whisper Protocol)
• web3.eth.ens (Ethereum Name Service)
• web3.eth.Iban (IBAN/BBAN support)
• web3.eth.subscribe
  • This one will probably be implemented inside Contract but it's not set in stone
• Bloom filters on web3.utils
• BatchRequest
• PromiEvent
• Access lists
• Extending modules
• Other individual functions across some modules ("if it's not in the docs, we're not missing it")