Cypress is the Klaytn mainnet, Baobab is a testnet. Below is information relating to each network.
Cypress mainnet:
EN download : Choose the Cypress package from the download page.
Public EN : https://api.cypress.klaytn.net:8651​
Klaytnscope : https://scope.klaytn.com​
Klaytn Wallet : https://wallet.klaytn.com​
Baobab testnet:
EN download : Choose the Baobab package from the download page.
Public EN : https://api.baobab.klaytn.net:8651​
Klaytnscope : https://baobab.scope.klaytn.com​
Klaytn Wallet : https://baobab.wallet.klaytn.com​
Baobab Faucet : https://baobab.wallet.klaytn.com/faucet​
Official Klaytn SDKs are provided in JavaScript and Java. See caver-js and caver-java. Community contributions are always welcome in providing Klaytn APIs in other languages.
To learn about how to build BApp using Klaytn SDK, see Tutorials.
Also, check the porting guidelines from web3.js and from web3j. Because the syntactic of caver-js and caver-java are very similar to web3.js and web3j, porting should be minimal and very straightforward. But, no, you can not use web3.js or web3j to make a request against Klaytn.
Yes and No. Endpoint node validates the blocks and exposes RPC APIs to the outer world. EN is always needed for your application to interact with the Klaytn network. For those who simply want to try Klaytn APIs, there are public ENs you can connect to. Note that they are provided as a testing purpose without SLA. Do not use them in production.
Cypress Public EN : https://api.cypress.klaytn.net:8651​
Baobab Public EN : https://api.baobab.klaytn.net:8651​
KAS (Klaytn API Service), similar to Infura for Ethereum, will be released in 1H 2020. With KAS, you can use Klaytn without running own Endpoint Node.
First, check if your HW specification meets the system requirements.
Check the fast sync. Klaytn publishes the chain data every day. Chain data is a database snapshot that stores all blocks generated since the genesis. Download the latest chain data for the fast sync.
Yes. Klaytn supports Solidity as a smart contract language. ERC-20 and ERC-721 written in Solidity for Etherem can be deployed and executed on Klaytn.
Further Klaytn-specific token standards can be defined. Follow the KIP (Klaytn Improvement Proposal) and join the discussion.
Yes. Truffle can be used in developing smart contracts on Klaytn with truffle-hdwallet-provider-klaytn. See Truffle and follow the configuration guideline.
If you are new to Truffle, see Testing Guide and Deployment Guide to get a rough idea on what you can do with Truffle.
No official browser wallets at the moment.
Kaikas, a browser extension wallet of Klaytn will be released in 1H 2020.
In Klaytn, the account address can be decoupled from the key pair.
Common use cases are as follows.
The account owner wants to change the key for security reasons.
The account has a weighted-multisig or a role-based key that allows having multiple key pairs to control the account.
Fee-payer accounts usually have a role-based key. In most cases, the account address is not derived from the RoleFeePayer key.
Check fee-delegation-example to get a complete working code of value transfer.
See the JavaScript code snippet for deploying a contract with fee-delegation. Note that you can not use Truffle for the contract deployment with fee-delegation.
​Sending a transaction with multiple signer gives a good explanation about two different ways of collecting signatures. Relevant caver-js APIs are as follows. Take a look at the code examples in the API description.