EVM-compatible DApps Integration

This document guides user how to integrate EVM-compatible Blockchains for DApps. This will apply to all the EVM-compatible Blockchains currently supported in Coin98 Wallet.

Supported EVM-compatible Blockchains

1. Ethereum

2. Viction

3. BNB Smart Chain

4. Polygon

5. Avalanche C-Chain

6. Arbitrum

7. Aurora

8. Base

9. Bittorrent Chain

10. Boba Network

11. Celo

12. Chiliz

13. Conflux

14. Core

15. Cronos

16. Ethereum PoW

17. f(x) Core EVM

18. Fantom

19. GateChain

20. Gnosis Chain

21. Harmony

22. HECO Chain

23. Humanode

24. KardiaChain

25. Klaytn

26. Kroma

27. KuCoin Commnunity Chain

28. Linea

29. Mantle

30. Moonbeam

31. Nautilus

32. Oasis Network

33. OKXChain

34. opBNB

35. Optimism

36. PlatON Network

37. Polygon zkEVM

38. Ronin

39. Scroll

40. StarkNet Theta Network

41. Theta Network EVM

42. zkSync Era

43. Ancient8 (Testnet)

44. Base (Testnet)

45. Taiko Jolnir (Testnet)

46. Mantle (Testnet)

47. Scroll (Testnet)

48. ZetaChain (Testnet)

To detect Coin98 Wallet with EVM-compatible Blockchains

To detect whether your browser is running Coin98 Wallet, please use:

if(window.coin98 || window.ethereum || window.ethereum?.isCoin98){
    // handle error here
}

Notice: The Coin98 Wallet on EVM JavaScript provider API is specified by EIP-1193 and EIP-6963. Support window.ethereum or window.coin98.provider only (window.web3is unsupported)

---

To connect Coin98 Wallet

To connect Coin98 Wallet means to access the user's [blockchain - like Ethereum] account(s).

// Connect & get accounts
window.coin98.provider.request({method: 'eth_accounts'});
// Alias for connection
window.coin98.provider.request({method: 'eth_requestAccounts'});​
//Check if dapp connected
window.coin98.provider.isConnected();
//Check if the caller's current permissions
window.coin98.provider.request({method: 'wallet_getPermissions'});
//Check if request the given permissions 
window.coin98.provider.request({method: 'wallet_requestPermissions'});

---

To disconnect Coin98 Wallet

To disconnect Coin98 Wallet, please use:

window.coin98.provider.disconnect()

To experience functions

Once your account is connected, let's start experiencing more functions.‌

Get Current Account

return Promise<Array[String]>

• If wallet can not be found, return [] instead of throw Error

window.coin98.provider.request({ method: 'eth_accounts' }).then(accounts => {
  if (accounts[0]) {
    // Do something with accounts
  } else {
    // Wallet not found
  }
})

Check wallet whether exists or not

return Promise<{data: Boolean}>

window.coin98.provider.request({ method: 'has_wallet', params: ['ethereum'] })
// Example
window.coin98.provider.request({ method: 'has_wallet', params: ['ethereum'] }).then(() => {
  // Wallet Exists
}).catch(e => { 
  // Wallet not found
})

Sign Transaction

return: Promise<Signature | RPC: 2.0>

// Example Sign Transactionconst
const signature = window.coin98.provider.request({
    method: 'eth_signTransaction',
    params: [
        "from": "string",
        "to": "string",
        "gas": "string",
        "gasPrice": "string",
        "value": "string",
        "data": "string",
        "nonce": "string"
    ]
});

Transfer

return Promise<hash>

window.coin98.provider.request({
  method: 'eth_sendTransaction',
  params: [
    {
      from: 'string',
      to: 'string',
      gas: 'string',
      gasPrice: 'string',
      value: 'string',
      data: 'string',
      nonce: 'string'
    }
  ]
})

Decrypt

return Promise<string>

window.coin98.provider.request({
  method: 'eth_decrypt',
  params: [encryptedMessage, accounts[0]],
  })
   .then((decryptedMessage) =>
    console.log('The decrypted message is:', decryptedMessage)
  )
  .catch((error) => console.log(error.message));
})

Get Encryption Public Key

return Promise<string>- The public encryption key of the Ethereum account whose encryption key should be retrieved

let encryptionPublicKey
window.coin98.provider.request({
  method: 'eth_getEncryptionPublicKey',
  params: [accounts[0]], // you must have access to the specified account
  })
  .then((result) => {
    encryptionPublicKey = result;
  })
  .catch((error) => {
    if (error.code === 4001) {
      // EIP-1193 userRejectedRequest error
      console.log("We can't encrypt anything without the key.");
    } else {
      console.error(error);
    }
  });

Encrypt

const ethUtil = require('ethereumjs-util');
const encryptedMessage = ethUtil.bufferToHex(
  Buffer.from(
    JSON.stringify(
      sigUtil.encrypt(
        {
          publicKey: encryptionPublicKey,
          data: 'hello world!,
          version: 'x25519-xsalsa20-poly1305',
        }
      )
    ),
    'utf8'
  )
);

Add EVM-compatible Chain

result - if the request was successful, and an error otherwise.

window.coin98.provider.request
interface AddEthereumChainParameter {
  chainId: string; // A 0x-prefixed hexadecimal string
  chainName: string;
  nativeCurrency: {
    name: string;
    symbol: string; // 2-6 characters long
    decimals: 18;
  };
  rpcUrls: string[];
  blockExplorerUrls?: string[];
  iconUrls?: string[]; // Currently ignored.
}

Switch Ethereum Chain

Result - if the request was successful, and an error otherwise.

try{
	await window.await ethereum.request({
	method: 'wallet_switchEthereumChain',
	    params: [{ chainId: '0xf00' }],
	});
} catch (switchError) {
  // This error code indicates that the chain has not been added to Coin98.
  if (switchError.code === 4902) {
    try {
      await ethereum.request({
        method: 'wallet_addEthereumChain',
        params: [
          {
            chainId: '0xf00',
            chainName: '...',
            rpcUrls: ['https://...'] /* ... */,
          },
        ],
      });
    } catch (addError) {
      // handle "add" error
    }
  }
  // handle other "switch" errors
}

Watch Asset

Result - true if the token was added, false otherwise

window.coin98.provider.request({
method: 'wallet_watchAsset',
    params: {
      type: 'ERC20',
      options: {
        address: '0xb60e8dd61c5d32be8058bb8eb970870f07233155',
        symbol: 'FOO',
        decimals: 18,
        image: 'https://foo.io/token-image.svg',
      },
    },
  })
  .then((success) => {
    if (success) {
      console.log('FOO successfully added to wallet!');
    } else {
      throw new Error('Something went wrong.');
    }
  })
  .catch(console.error);

RPC Request

return Promise<Ethereum RPC> Currently only support HTTP(s) method Reference: RPC Method

window.coin98.provider.request({method: '<Your Method>', params: [args1,....]})

Experimental MultiChain Connection (under maintenance)

You can connect and receive multiChain address at the same time by using the following methods

async function connect(){
	if(!window.coin98){
		throw new Error('Coin98 Wallet is required');
	}
	const accounts = await window.coin98.connect([<chain 1>, <chain 2>, ...]);
	
	if(!accounts){
		throw new Error('Connect Error | User cancel your request');
	}
	
	// Do anything with accounts:[<address of chain 1>, <address of chain 2>]
}

When your connection is successful, chain's properties will be available for your next request. For example:

// For example | connect ether & solana
async function connect(){
	const conn = await window.coin98.connect(['ether','solana']);
	// If user accept the request, those properties will available at window.coin98;
	//  window.solana || Checkout document of solana connection guide for more methods;
	//	window.ether || Checkout document of ether connection guide for more methods;
}

Chain's Name can be found at

const { CHAIN_NAME } = window.coin98

Subscription

Support subscribe using JSON-RPC notifications. This allows clients to wait for events instead of polling for them. All results will be released at data event.

Methods

// For Subscribe
window.coin98.provider.request({
	method: 'eth_subscribe',
	params: ['<type>','<options>']
})
// Its result will be subscription ID which can be used for unsubscribe
// For Unsubscribe
window.coin98.provider.request({
	method: 'eth_unsubscribe',
	params: ['<Subscription ID>']
});

Example

// Subscribe for event
const subscriptionID = window.coin98.provider.request({
    method: 'eth_subscribe',
	params: ["logs", 
	{
		address: "0x8320fe7702b96808f7bbc0d4a888ed1468216cfd", 
		topics: ["0xd78a0cb8bb633d06981248b816e7bd33c2a35a6089241d099fa519e361cab902"]}]
})
// You can listen for incoming notifications by
window.coin98.provider.on("data", data => {
	// Do the rest of your work with data
})

---

To handle events

List of events

Currently we only support some action events from Wallet

window.coin98.provider.on('event_name', callback);
​//Example
window.coin98.provider.on('close', () => window.location.reload());
window.coin98.provider.on('accountsChanged', () => window.location.reload());

Events	Trigger
accountsChanged	Receive when active account changed in Wallet
networkChanged	Receive when active network changed in Wallet
chainChanged	Receive when active chain changed in Wallet
disconnect	Receive when disconnecting from Wallet
close	Alias for disconnect event

IMPORTANT: We strongly recommend reloading the page upon chainChanged, unless you have a good reason not to

Method	Description
on(event, callback)	Add event listener
off(event, callback)	Remove event listener