Cypress is the Klaytn mainnet, Baobab is a testnet. Below is information relating to each network.
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
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
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.
Further Klaytn-specific token standards can be defined. Follow the KIP (Klaytn Improvement Proposal) and join the discussion.
No official browser wallets at the moment.
Kaikas, a browser extension wallet of Klaytn will be released in 1H 2020.
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.
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.