Overledger Javascript SDK
Developer's guide to use Overledger SDK written in Javascript by Quant Network.
Introduction to the Overledger SDK
Overledger is an operating system that allows distributed apps(MApps) to connect to multiple distributed ledger technologies (DLTs) or blockchains. The Overledger SDK allows developers to create signed transactions & send them simultaneously to all supported DLTs.
Technologies
The Overledger SDK is a node module written in Javascript/ES6.
Prerequisites
- Register for a free developer account on Quant Developer's Portal
- You will require a MAppId and BPI key:
- Register your application in order to get a free MApp ID.
- Verify your Quant token, and create a BPI key.
Installation
The Overledger SDK can be easily installed as an npm module. This will ensure that all required dependencies are automatically included.
npm install @quantnetwork/overledger-sdk
Or if you prefer Yarn as the package manager.
yarn add @quantnetwork/overledger-sdk
Development
To run the SDK in development mode, run the command npm run dev and every change will be automatically built.
Getting started
NodeJS with babel
import OverledgerSDK from "@quantnetwork/overledger-sdk";
NodeJS
const OverledgerSDK = require("@quantnetwork/overledger-sdk").default;
Initialize the SDK with the 3 available dlts. Optionally, a timeout period can be specified (by default it's 5000ms).
const overledger = new OverledgerSDK("mappId", "bpiKey", {
dlts: [{ dlt: "bitcoin" }, { dlt: "ethereum" }, { dlt: "ripple" }],
timeout: 1500, // Optional
});
Usage
The SDK provides the following functions which return a promise with a standard axios response which includes the BPI data in the data field:
- Main functions
- DLT functions
configure
Configure DLTs.
Usage: configure(options)
Parameters
This function has DLT Names as parameter.
| Name | Type | Description |
|---|---|---|
options |
Object | Object of the options type |
Return Value
This function does not have a return value.
sign
Sign a transaction for a DLT.
Usage: sign(dlts)
Parameters
This function takes an array of DLT transaction data.
| Name | Type | Description |
|---|---|---|
dlts |
array | Array of DLT transaction data (DLT Name, From Address, To Address and Data) |
Example of DLT transaction data:
Because the data differs between blockchain, the options object contains all the non-generic variables and can be different in each blockchain.
[
{
dlt: "bitcoin",
toAddress: "2NFj2CVhE5ru7werwXUNCbirUW6KDo2d",
message: "QNT test",
options: {
amount: 1,
sequence: 2, // VOUT
previousTransactionHash: '77b04805f40a7cba6ed49be10d200f41462bfa266f24db91114798178c802058',
feePrice: 1e5,
value: 1
}
},
{
dlt: "ethereum",
toAddress: "0x0000000000000000000000000000000000000000",
message: "QNT test",
options: {
amount: '1', // Amount in wei (1 ETH = 10^18 wei)
sequence: 2, // nonce
feeLimit: '10',
feePrice: '10',
}
},
{
dlt: "ripple",
toAddress: "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh",
message: "QNT test",
options: {
amount: '1', // Amount in drops (1 XRP = 1,000,000 drops)
feePrice: '0.000012', // Standard fee price on the XRP network
sequence: 1, // Transaction index number for this account (e.g if it's the first transaction after funding the address, sequence is 1)
maxLedgerVersion: 4294967295, // This is the maximum value that this option field can take
}
}
];
Return Value
This function returns a Promise which resolves with a signedTransaction string.
send
Send the signed transaction to the blockchain.
Usage: send(signedTransactions)
Parameters
This function takes Signed Transaction Hash as parameter.
| Name | Type | Description |
|---|---|---|
signedTransactions[object] |
object | Object of signed transaction |
signedTransactions = [
{
dlt: 'bitcoin',
signedTransaction: 'SIGNEDTRANSACTIONHASH',
},
{
dlt: 'ethereum',
signedTransaction: 'SIGNEDTRANSACTIONHASH',
},
]
Return Value
This function returns Transaction Hash
readTransactionsByMappId
Read all transactions submitted by the mapp connected to the current API session.
Parameters
This function has no parameters.
Return value
This function returns a promise that resolves with an array of Overledger transaction objects with the following fields:
| Name | Type | Description |
|---|---|---|
mappId |
string | Identifier of a multi-chain application |
overledgerTransactionId |
string | A transaction hash used to identify it, represented in hexadecimal |
timestamp |
string | The timestamp when the transaction was received by Overledger |
dltData |
array | Array of dltData type objects |
readByTransactionId
Read an Overledger transaction by its ID.
Parameters
| Name | Type | Description |
|---|---|---|
id |
String | A transaction hash used to identify it, represented in hexadecimal |
Return value
This function returns a promise that resolves with an Overledger transaction containing the following fields:
| Name | Type | Description |
|---|---|---|
mappId |
string | Identifier of a multi-chain application |
overledgerTransactionId |
string | A transaction hash used to identify it, represented in hexadecimal |
timestamp |
string | The timestamp when the transaction was received by Overledger |
dltData |
array | Array of objects of the dltData type |
setMappId
Set the multi-chain application ID.
Usage: setMappId('network.quant.helloworld');
Parameters
| Name | Type | Description |
|---|---|---|
id |
String | String representation of a multichain application id |
Return value
This functionns has no return value
getMappId
Get the multi-chain application identifier.
Usage: const mappId = getMappId();
Parameters
This function has no parameters.
Return value
This function returns a string representing the multi-chain application identifier.
| Name | Type | Description |
|---|---|---|
id |
string | String representation of a multichain application id |
setBpiKey
Set the Blockchain Programming Interface key.
Usage: setBpiKey('bpiKey');
Parameters
| Name | Type | Description |
|---|---|---|
bpiKey |
string | String representation of a BPI key. |
Return value
This functions has no return value
getBpiKey
Get the currently set Blockchain Programming Interface key.
Usage: const bpiKey = getBpiKey();
Parameters
This function has no parameters
Return value
This function returns a string representing the bpi key that is currently used.
| Name | Type | Description |
|---|---|---|
bpiKey |
string | String representation of the BPI key. |
getBalances
Get the balances of multiple addresses Usage:
const request = [
{
"dlt": "ethereum",
"address": "0x0000000000000000000000000000000000000000"
},
{
"dlt": "ripple",
"address": "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh"
}
]
overledger.getBalances(request);
Parameters
This function accepts an array of objects with the following fields:
| Name | Type | Description |
|---|---|---|
dlt |
string | The dlt where this address should be searched on |
address |
string | The address for the balance query |
Return value
This function returns an array of objects with the following fields.
| Name | Type | Description |
|---|---|---|
dlt |
string | The DLT which the request has been submitted to |
address |
string | The address holding the balance |
unit |
string | The unit; satoshi for bitcoin, wei for ethereum, drops for ripple |
value |
string | The amount of units this address holds |
getSequences
Get the sequences of multiple addresses Usage:
const request = [
{
"dlt": "ethereum",
"fromAddress": "0x0000000000000000000000000000000000000000"
},
{
"dlt": "ripple",
"fromAddress": "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh"
}
]
overledger.getSequences(request);
Parameters
This function accepts an array of objects with the following fields:
| Name | Type | Description |
|---|---|---|
dlt |
string | The dlt where this address should be searched on |
fromAddress |
string | The address for the sequence query |
Return value
This function returns an array of objects with the following fields.
| Name | Type | Description |
|---|---|---|
dlt |
string | The DLT which the request has been submitted to |
sequence |
string | The sequence number of this address |
Faucet
As per default it would take the configured address.
From the DLT level overledger.dlts.[dlt]
Fund an account on our testnet.
Usage: fundAccount(amount?, address?)
Parameters
| Name | Type | Description |
|---|---|---|
amount |
string | Optional The amount of tokens to fund, in the smallest unit (satoshi for Bitcoin, wei for Ethereum or drops for Ripple) |
address |
string | Optional The address to fund |
Return Value
This function returns a Promise
Types
In this section we will provide a description of the common object types.
overledgerTransaction
| Name | Type | Description |
|---|---|---|
mappId |
string | Identifier of a multi-chain application |
overledgerTransactionId |
string | A transaction hash used to identify it, represented in hexadecimal |
timestamp |
string | The timestamp when the transaction was received by Overledger |
dltData |
array | Array of objects of the dltData type |
dltData
| Name | Type | Description |
|---|---|---|
dlt |
string | String representation of the BPI key. |
message |
string | Data to be sent to the DLT |
fromAddres |
string | Sender address |
toAddress |
string | Destination address |
changeAddress |
string | Address for the change to be submitted to |
fee |
string | Fee to pay for the transaction, represented in the lowest unit on the network (e.g.: satoshi, wei, drop etc) |
feeLimit |
string | Maximum fee to pay for the transaction to be submitted on the DLT |
callbackUrl |
string | Endpoint provided by the Mapp for the BPI layer to call back |
signedTransaction |
string | Hexadecimal string representation of a signed transaction |
Account
From the DLT level overledger.dlts.[dlt]
Set Account
This function sets the default account for the specified blockchain into the SDK, every transaction will be signed by this account
Usage: setAccount(privateKey)
Must be a WIF key for bitcoin
Parameters
This function takes: - privateKey: the privateKey belonging to the specified blockchain
Return Value
This function has no return value.
Get Account
This function gets the default account for the specified blockchain from the SDK
Usage: overledger.dlts.[dlt].account
Return Value
This function returns
{
privateKey: 'string' // The privateKey belonging to the specified blockchain
address: 'string' // The address belonging to this privateKey
}
For bitcoin, the privateKey is in the WIF format
Create Account
This function creates an account for the specified blockchain from the SDK
Usage: overledger.dlts.[dlt].createAccount()
Return Value
This function returns
{
privateKey: 'string' // The privateKey belonging to the specified blockchain
address: 'string' // The address belonging to this privateKey
}
For bitcoin, the privateKey is in the WIF format
getBalance
Get the balance of an address or, by default, the account that is currently set.
Usage: overledger.dlts.{dltName}.getBalance(address);
Parameters
| Name | Type | Description |
|---|---|---|
address |
string | Optional address. |
Return value
This function returns an object with the following fields.
| Name | Type | Description |
|---|---|---|
dlt |
string | The DLT which the request has been submitted to |
address |
string | The address holding the balance |
unit |
string | The unit; satoshi for bitcoin, wei for ethereum, drops for ripple |
value |
string | The amount of units this address holds |
getSequence
Get the sequence of an address
Usage: overledger.dlts.{dltName}.getSequence('0x0000000000000000000000000000000000000000');
Parameters
| Name | Type | Description |
|---|---|---|
fromAddress |
string | The address for the sequence query |
Return value
This function returns an array of objects with the following fields.
| Name | Type | Description |
|---|---|---|
dlt |
string | The DLT which the request has been submitted to |
sequence |
string | The sequence number of this address |
Usage Example
In this simple usage example we will call the getBalance method to request the balance of the genesis address on Ripple (created by the blockchain on startup).
npm install @quantnetwork/overledger-sdk
// Boilerplate
const OverledgerSDK = require("@quantnetwork/overledger-sdk").default;
// Replace mappId and bipKey with your own credentials.
const overledger = new OverledgerSDK("mappId", "bpiKey", {
dlts: [{ dlt: "bitcoin" }, { dlt: "ethereum" }, { dlt: "ripple" }]
});
// Method call
;(async () => {
const rippleAddress = "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh"
const response = await overledger.dlts.ripple.getBalance(rippleAddress);
var rippleGenesisBalance = response.data
// The lowest unit in XRP is called 'drop'
console.log("The balance of the genesis address on the Quant Ripple Testnet is", rippleGenesisBalance.value, rippleGenesisBalance.unit);
})();
