March 2018
Beginner to intermediate
656 pages
20h 9m
English
Content preview from Mastering Blockchain - Second Edition
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
Web3
Web3 is a JavaScript library that can be used to communicate with an Ethereum node via RPC communication. Web3 works by exposing methods that have been enabled over RPC. This allows the development of user interfaces that make use of the Web3 library in order to interact with the contracts deployed over the blockchain.
In order to expose the methods via geth, the following command can be used:
$ geth --datadir .ethereum/privatenet/ --networkid 786 --rpc --rpcapi 'web3,net,eth,debug' --rpcport 8001 --rpccorsdomain 'http://localhost:7777'
The --rpcapi flag allows the web3, eth, net, and debug methods.
This is a powerful library and can be explored further by attaching a geth instance. Later in this section, you will be introduced to the ...