0chain Client SDK for Node

This is Node.js implementation of 0chain js-client-sdk. Use this SDK to interact with 0Chain blockchain. The SDK supports wallet creation, transaction submission and verification. In addition to that, the sdk provides APIs to query blockchain health itself. See example.js file for more details.

Installation

Via Github: https://github.com/0chain/js-client-sdk

APIs

All functions except init() returns promise.

First import / require the library from github https://github.com/0chain/js-client-sdk

import jsClientSdk from 'js-client';

Initialize

Before any function in the SDK to be called, the init function with the cluster configuration and bls-wasm instance should be called.

bls-wasm dependency

While initialising js-client-sdk, a bls instance is to be passed. bls can be installed via npm using the below command:

npm install bls-wasm

Github Repository: https://github.com/herumi/bls-wasm

Input Parameters

config -- json string containig cluster configuration

Output

None

The below code shows an example of initiailizing the SDK with 0chain-local-cluster.

var config = {
    "miners": [
    "http://one.devnet-0chain.net:31071/",
    "http://one.devnet-0chain.net:31072/",
    "http://one.devnet-0chain.net:31073/",
    "http://one.devnet-0chain.net:31074/",
    "http://one.devnet-0chain.net:31075/",
    "http://one.devnet-0chain.net:31076/",
    "http://one.devnet-0chain.net:31077/",
    "http://one.devnet-0chain.net:31078/",
    "http://one.devnet-0chain.net:31079/"
  ],
  "sharders": [
    "http://one.devnet-0chain.net:31171/",
    "http://one.devnet-0chain.net:31172/",
    "http://one.devnet-0chain.net:31173/",
    "http://one.devnet-0chain.net:31174/",
    "http://one.devnet-0chain.net:31175/",
    "http://one.devnet-0chain.net:31176/",
    "http://one.devnet-0chain.net:31177/",
    "http://one.devnet-0chain.net:31178/",
    "http://one.devnet-0chain.net:31179/"
  ],
  "chain_id" :   "0afc093ffb509f059c55478bc1a60351cef7b4e9c008a53a6cc8241ca8617dfe",
  "clusterName" : "0chain-local-cluster",
  "proxyServerUrl" : "http://localhost:9082",
  "transaction_timeout" : 20,
  "state " : true
}
jsClientSdk.init(config, bls)

To use local cluster, call init with bls-wasm instance configuration

jsClientSdk.init(bls)

registerClient

Registers a client with 0Chain Blockchain.

Input Parameters None

Output

Wallet object in case of successful promise resolved.

jsClientSdk.registerClient()

restoreWallet

Restore a existing client with 0Chain Blockchain. Need to pass the secret mnemonic

Input Parameters

mnemonic -- string

Output

Wallet --if successful. Error otherwise

jsClientSdk.restoreWallet(mnemonic)

sendTransaction

Use this function send tokens from one wallet to the other.

Input Parameters

fromAccount - From Wallet

toWalletId - To wallet clientId

value - amount to send

note - description for the transaction

Ouput

Transaction --if successful. Error otherwise

jsClientSdk.sendTransaction(fromAccount, toWalletId, value, note)

storeData

Use this function to store data on a wallet

Input Parameters

fromAccount - From Wallet

data - data to save in the blockchain (string type)

note - description for the transaction

Ouput

Transaction --if successful. Error otherwise

jsClientSdk.storeData(fromAccount, data, note)

checkTransactionStatus

Use this function to check the status of the transaction that has been placed earlier.

Note Transaction status will be available only after the transaction is processed. Please provide at least 3 seconds time for the transaction to process. You can check status multiple times.

Input Parameters

hash - Hash of the transaction that was placed earlier

Ouput

TransactionDetails -- Details of the transaction which has the status field.

jsClientSdk.checkTransactionStatus(hash)

getBalance

Use this function to get the balance of particular wallet.

Input Parameters

client_id - The clientId whose balance you are interested in

Ouput

TransactionDetails -- Details of the transaction which has the balance field.

jsClientSdk.getBalance(client_id)

executeSmartContract

sends a transaction of the specified amount as mentioned in the value parameter fromAccount toWalletId.

Input Parameters

fromAccount - from Wallet

smartContractAddress - address of intended smartContract

payload - depends on the smartContract function that is being executed

transactionValue - transaction value --by default zero

Output Transaction -- object if successful.

jsClientSdk.executeSmartContract(fromAccount, smartContractAddress, payload, transactionValue)

getBlockInfoByHash

Use this function to get the block summary or block detail by block hash.

Input Parameters

hash -- hash of the block

options -- use BlockInfoOptions.HEADER to get only the summary or BlockInfoOptions.Full to get entire block. Default is HEADER

callback -- function to be called upon success

errCallback -- function to be called upon failure

Output

Block Summary or Block object depending on the options specified

jsClientSdk.getBlockInfoByHash(hash, options, callback, errCallback)

getBlockInfoByRound

Use this function to get the block summary or block detail by round number.

Input Parameters

round -- round number options -- use BlockInfoOptions.HEADER to get only the summary or BlockInfoOptions.Full to get entire block. Default is HEADER

callback -- function to be called upon success

errCallback -- function to be called upon failure

Output

Block Summary or Block object depending on the options specified

jsClientSdk.getBlockInfoByRound(round, options, callback, errCallback)

getChainStats

Use this function to get current information about the blockchain like current roundnumber, average block generation/finalization time, etc

Input Parameters

none

Output

ChainStats --an object that has detailed information about the blockchain.

jsClientSdk.getChainStats()

getLatestFinalized

use this function to get the last finalized block summary.

Input Parameters

None

Output

BlockSummary --object if successful that has information of latest finalized block

jsClientSdk.getLatestFinalized()

getRecentFinalized

Use this function to get summaries of last 10 recently finalized blocks.

Input Parameters

none

Output

array of BlockSummary . --if successful.

jsClientSdk.getRecentFinalized()

Example file

The SDK also comes with an example.js file that demonstrates how the APIs can be used.