Bridge is a tool designed to make running Echo dApps for people as easy as possible.
As an extension for browser, Bridge can act as a dedicated Echo wallet, allowing to access and manage account data, manage multiple accounts, and use it for making, signing transactions & viewing account history.
The Echo Bridge is a bridge between a website that uses the Echo network and directly the Echo network itself. Implementing DApps using the extension, developers do not need to spend time implementing connections to network nodes, launching nodes, and managing user private keys, since all this has been moved to the Echo Bridge side.
On a site that is open in a browser with Echo Bridge, an object is available
window.echojslib, which is initialized by the extension. Using this object
you can communicate with the Echo node, work with user accounts, and also
sign and send transactions to the network.
Most actions that affect work with accounts and private keys must be confirmed by the user through the Bridge UI.
Before connecting to Bridge you should get access:
/**
* Get access
* @returns {Promise.<Boolean>} status
*/
echojslib.extension.getAccess();This method returns Promise which will be resolved when a user approves the request or rejected when failure. This request should always go first, even if access has already been granted earlier. In this case, the extension will not request access again and just resolves the promise.
There is an example of connecting to the node and subscribe to switch network
(recommended to use inside window.onload)
window.onload = async () => {
// you do not need to use the isEchoBridge flag,
// but you can be sure that you did not override
// the variable above
if (echojslib && echojslib.isEchoBridge) {
/**
* Get access
*/
await echojslib.extension.getAccess();
/**
* Subscribe to current Echo network selected in Bridge
*/
await echojslib.extension.subscribeSwitchNetwork(async () => {
if (echojslib.echo.isConnected) {
await window.echojslib.echo.disconnect();
}
/**
* Connect to current Echo network selected in Bridge
*/
await echojslib.echo.connect();
});
}
}; Callback will be called, when network will be changed in extension.
Subscribe to change active account. Callback will be triggered when active account is changed or bridge will be locked/unlocked
echojslib.extension.subscribeAccountChanged((account) => console.log(account)); // null or "1.2.3"If you don't get access or there isn't active account, then you get null, else account id.
/**
* @example
* echojslib.extension.activeAccount // null
* @example
* echojslib.extension.activeAccount // "1.2.1"
* @return {null|string}
*/
echojslib.extension.activeAccountThis method returns Promise which will be resolved when a user unlock Bridge.
/**
* @example
* await echojslib.extension.requestAccount(); // null|"1.2.3"
* @return {null|string}
*/
await echojslib.extension.requestAccount()Simple example of creating and broadcasting transaction
const sendTransaction = async () => {
/**
* Create a transaction
* @type {Transaction}
*/
const tr = window.echojslib.echo.createTransaction();
/**
* Add transfer operation
*/
tr.addOperation(echojslib.constants.OPERATIONS_IDS.TRANSFER, {
from: "1.2.1",
to: "1.2.2",
amount: { asset_id: "1.3.0", amount: 10 }
});
/**
* Sign the transaction with Bridge
*/
await tr.signWithBridge();
/**
* Send the transaction to blockchain
*/
await tr.broadcast();
}See the examples for more different transactions.
In order for the user to confirm ownership of the account's private key, the extension suggests using the proofOfAuthority method. The method provides an opportunity to sign payload by account private key. Because the raw signing can potentially sign transactions or even leak its private key we have to add an extra layer of encryption. So the extension will sign payload instead of raw data.
/**
* Get signature
* @returns {Promise.<String>} signature
*/
await echojslib.extension.proofOfAuthority('This is example message!', '1.2.134');To verifying the signature use echojs-lib.
import { ED25519 } from 'echojs-lib';
import bs58 from 'bs58';
const signature = Buffer.from('757a8b60f4c348e8de49f8dc56563db5d9903be41c7aad145cc8be5c6f66804c168693232c0f150ef017bc01697fc0aca5000a04ac6756d36430aeaefe518b08', 'hex');
const message = Buffer.from('This is example message!', 'utf8');
const publicKey = bs58.decode('ECHOJDpsaMaR9qWM2922ZYvQ3xpavsN8oeNN8zBx1VNKdQBf'.slice(4));
ED25519.verifyMessage(signature, message, publicKey);You can sign payload by account private keys.
/**
* Get signature
* @returns {Promise.<String>} signature
*/
await echojslib.extension.signData(Buffer.from('This is example message!', 'utf8'), '1.2.134');The MIT License (MIT)
Copyright (c) Echo Technological Solutions LLC
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