Wallet api

SPC Chain Wallet injects a global API into websites visited by its users at window.SPC Chain.

This API specification borrows heavily from API MetaMask provided, considering the massive adoption. So Web3 site developers can easily connect their dApps with the SPC Chain Wallet. The APIs allow websites to request users' SPC Chain addresses, read data from the blockchain the user is connected to, and prompt the users to sign messages and transactions.

The presence of the provider object window.SPC Chain indicates a SPC Chain/SPC Chain user.

The API this extension wallet provides includes API specified by EIP-1193 and API defined by MetaMask (including some massively relied legacy ones).

Development Progress

Currently (version 1.112.8) as SPC Chain Wallet natively supports SPC Chain, we are planning to open a series of APIs for dApp developers to interact with SPC Chain. At the end of the day, most APIs available in SPC Chain javascript sdk would be available.

Currently, only the following is supported: * transfer

Difference with MetaMask

Warning

Please read through this section if you are a web3 developer who has integrated with MetaMask and interested in integrating with SPC Chain Wallet.

Inpage injected object

The biggest difference between SPC Chain Wallet and MetaMask is we inject SPC Chain rather than ethereum (or web3) to the web page. So user could keep two extensions at the same time.

SPC Chain.request({method: "eth_sign", params: ["address", "message"])

We haven't supported the full complex signing data APIs MetaMask provided, while we only provide standard eth_sign JSON-RPC call.

The message item in params for this request on MetaMask has to be hex-encoded keccak256 hash (otherwise the API would silent failure for dapp https://www.reddit.com/r/Metamask/comments/9wp7kj/eth_sign_not_working/). In contrast, web3 developers could pass any message in plaintext to this method, and our UI would render it as it is to the wallet users.

SPC Chain.request({method: "eth_accounts"})

When this API is invoked without the user's approval, MetaMask would return an empty array.

In contrast, we would ask the user to unlock his wallet and return the address user connected to.

Upcoming Breaking Changes

Warning

Important Information

On November 16, 2020, MetaMask is making changes to their provider API that will be breaking for some web3 sites. These changes are upcoming, but you can prepare for them today. Follow this GitHub issue for updates.

In this implementation, some APIs will be supported as Legacy API (For example we will still implement the chainIdChanged on SPC Chain object until MetaMask formally deprecates it).

Basic Usage

For any non-trivial SPC Chain web application — a.k.a. web3 site — to work, you will have to:

Detect the SPC Chain provider (window.SPC Chain)
Detect which SPC Chain network the user is connected to
Get the user's SPC Chain account(s)

You can learn how to accomplish the 2 and 3 from above list by reviewing the snippet in the Using the Provider section.

The provider API is all you need to create a full-featured web3 application.

That said, many developers use a convenience library, such as ethers and web3.js, instead of using the provider directly. If you need higher-level abstractions than those provided by this API, we recommend that you use a convenience library.

Today, many dApps are built on top of the higher-level API provided by web3-react or use-wallet (which builds on top of web3-react).

web3-react

We made a tiny lib nc-connector that implements the AbstractConnector interface of web3-react library. You can add this to your project in parallel with injected-connector by: yarn add @shree-chain/nc-connector or npm i @shree-chain/nc-connector.

import { BscConnector } from '@shree-chain/nc-connector'

export const spc = new BscConnector({
  supportedChainIds: [56, 97] // later on 1 ethereum mainnet and 3 ethereum ropsten will be supported
})

// invoke method on spc e.g.
await spc.activate();
await spc.getAccount();
await spc.getChainId();

use-wallet

There is an example in use-wallet origin repo shows how to 'inject' a customized web3-react connector to UseWalletProvider:

function App() {
  const { account, connect, reset, status } = useWallet()
  return (
    <div>
      <h1>SPC Chain Connector</h1>
      {status === 'disconnected' ? (
        <button onClick={() => connect('spc')}>Connect</button>
      ) : (
        <button onClick={() => reset()}>Disconnect</button>
      )}
      {account && <p>Connected as {account}</p>}
    </div>
  )
}

render(
  <UseWalletProvider
    connectors={{
      spc: {
        web3ReactConnector() {
          return new BscConnector({ supportedChainIds: [56, 97] })
        },
        handleActivationError(err) {
          if (err instanceof UserRejectedRequestError) {
            return new ConnectionRejectedError()
          }
        },
      },
    }}
  >
  <App />
  </UseWalletProvider>,
  document.getElementById('root')
)

Chain IDs

Warning

At the moment, the SPC Chain.chainId property and the chainChanged event should be preferred over the eth_chainId RPC method.

Their chain ID values are correctly formatted, per the table below.

eth_chainId returns an incorrectly formatted (0-padded) chain ID for the chains in the table below, e.g. 0x01 instead of 0x1. See the Upcoming Breaking Changes section for details on when the eth_chainId RPC method will be fixed.

Custom RPC endpoints are not affected; they always return the chain ID specified by the user.

These are the IDs of the SPC Chains that SPC Chain Wallet supports by default.

Hex	Decimal	Network
0x38	56	SPC Chain Main Network (nc-mainnet)
0x61	97	SPC Chain Test Network (nc-testnet)

This API can also return chain ids of SPC Chains if users switch to them. The possible return value would be: | Chain Id | Network | | -------------------- | ---------------------------------------- | | SPC-Chain-Tigris | SPC Chain Main Network (bbc-mainnet) | | SPC-Chain-Ganges | SPC Chain Test Network (bbc-testnet) |

Properties

SPC Chain.chainId

Warning

The value of this property can change at any time, and should not be exclusively relied upon. See the chainChanged event for details.

NOTE: See the Chain IDs section for important information about the SPC Chain Wallet provider's chain IDs.

A hexadecimal string representing the current chain ID.

SPC Chain.autoRefreshOnNetworkChange

As the consumer of this API, it is your responsibility to handle chain changes using the chainChanged event. We recommend reloading the page on chainChange unless you have a good reason not to.

Please refer to MetaMask Doc, the only difference is we injected a different object.

To disable this behavior, set this property to false immediately after detecting the provider:

SPC Chain.autoRefreshOnNetworkChange = false;

Methods

SPC Chain.isConnected()

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.isConnected(): boolean;

SPC Chain.request(args)

Please refer to MetaMask Doc, the only difference is we injected a different object.

We use this method to wrap an RPC API, Please see the Ethereum wiki.

Important methods from this API include:

interface RequestArguments {
  method: string;
  params?: unknown[] | object;
}

SPC Chain.request(args: RequestArguments): Promise<unknown>;

Example

The code snippet below is as same as MetaMask's example, the only difference is we injected a different object.

params: [
  {
    from: '0xb60e8dd61c5d32be8058bb8eb970870f07233155',
    to: '0xd46e8dd67c5d32be8058bb8eb970870f07244567',
    gas: '0x76c0', // 30400
    gasPrice: '0x9184e72a000', // 10000000000000
    value: '0x9184e72a', // 2441406250
    data:
      '0xd46e8dd67c5d32be8d46e8dd67c5d32be8058bb8eb970870f072445675058bb8eb970870f072445675',
  },
];

SPC Chain
  .request({
    method: 'eth_sendTransaction',
    params,
  })
  .then((result) => {
    // The result varies by by RPC method.
    // For example, this method will return a transaction hash hexadecimal string on success.
  })
  .catch((error) => {
    // If the request fails, the Promise will reject with an error.
  });

SPC Chain.spcSign(address: string, message: string): Promise<{publicKey: string, signature: string}>

We prepared an example for this API, please check out:https://github.com/spccoin/SPCChain/js-eth-personal-sign-examples for more detail

Like eth_sign enable dapp to verify a user has control over an ethereum address by signing an arbitrary message. We provide this method for dapp developers to request the signature of arbitrary messages for SPC Chain (BC) and SPC Chain (SPC).

If address parameter is a shree chain address (start with spc or tspc), we will simply calculate sha256 hash of the message and let user sign the hash with his shree chain address' private key. Note: SPC Chain uses the same elliptic curve (secp256k1) as Ethereum.

If address parameter is a SPC Chain address (start with 0x), the message would be hashed in the same way with eth_sign.

The returned publicKey would be a compressed encoded format (a hex string encoded 33 bytes starting with "0x02", "0x03") for SPC Chain. And uncompressed encoded format (a hex string encoded 65 bytes starting with "0x04").

The returned signature would be bytes encoded in hex string starting with 0x. For SPC Chain, its r,s catenated 64 bytes in total. For SPC Chain, like eth_sign, its r, s catenated 64 bytes and a recover byte in the end.

Warning

DApp developers should verify whether the returned public key can be converted into the address user claimed in addition to an ECDSA signature verification. Because any plugin can inject the same object SPC Chain as SPC Chain Wallet.

SPC Chain.switchNetwork(networkId: string): Promise<{networkId: string}>

As SPC Chain Wallet natively supports SPC Chain and SPC Chain which are heterogeneous blockchains run in parallel. APIs would be different in any situation. (We would open APIs for SPC Chain very soon).

Developers could judge which network is selected by user currently via SPC Chain.chainId or listening to the chainChanged event via SPC Chain.on('chainChanged', callback).

To request for network switching, developers could invoke this API with bbc-mainnet (SPC Chain Main Network), nc-mainnet (SPC Chain Main Network), bbc-testnet (SPC Chain Test Network), nc-testnet (SPC Chain Test Network) to prompt user to agree on network switching.

SPC Chain.requestAccounts()

Request all accounts maintained by this extension.

The id in response would be used as accountId for the APIs for SPC Chain.

This method would return an array of Account:

{
  addresses: [{address: string, type: string}],
  icon: string,
  id: string,
  name: string
}

For example:

[
    {
        "id":"fba0b0ce46c7f79cd7cd91cdd732b6c699440acf8c539d7e7d753d38c9deea544230e51899d5d9841b8698b74a3c77b79e70d686c76cb35dca9cac0e615628ed",
        "name":"Account 1",
        "icon":"data:image/svg+xml;base64,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",
        "addresses":[
            {
                "type":"bbc-testnet",
                "address":"tspc1akt8vgstdaz8pax5zgykzee5u9kamjdkkcf2dw"
            },
            {
                "type":"bbc-mainnet",
                "address":"spc1akt8vgstdaz8pax5zgykzee5u9kamjdkcdqwdl"
            },
            {
                "type":"eth",
                "address":"0x43364696e478E344E95831CE8427623202e5CBFb"
            }
        ]
    }
]

SPC Chain.transfer({fromAddress:string, toAddress:string, asset:string, amount:number, memo?: string, sequence?: number, accountId:string, networkId:string})>

Transfer certain amount of asset (SPC or BEP2) on SPC Chain.

accountId could be retrieved from the SPC Chain.requestAccounts API (id field of each account)

networkId could be bbc-mainnet or bbc-testnet

For example:

This will ask the user's approval for transferring 1 SPC to himself. SPC Chain.transfer({fromAddress:"tspc1sndxdzsg42jg8lc0hehx8dzzpyfxrvq937mt0w", toAddress:"tspc1sndxdzsg42jg8lc0hehx8dzzpyfxrvq937mt0w", asset:"SPC", amount:1, accountId:"fba0b0ce46c7f79cd7cd91cdd732b6c699440acf8c539d7e7d753d38c9deea544230e51899d5d9841b8698b74a3c77b79e70d686c76cb35dca9cac0e615628ed", networkId:"bbc-testnet"})
This will ask the user's approval for transferring 1 BUSD to himself. SPC Chain.transfer({fromAddress:"tspc1sndxdzsg42jg8lc0hehx8dzzpyfxrvq937mt0w", toAddress:"tspc1sndxdzsg42jg8lc0hehx8dzzpyfxrvq937mt0w", asset:"BUSD-BAF", amount:1, accountId:"fba0b0ce46c7f79cd7cd91cdd732b6c699440acf8c539d7e7d753d38c9deea544230e51899d5d9841b8698b74a3c77b79e70d686c76cb35dca9cac0e615628ed", networkId:"bbc-testnet"})

Events

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('accountsChanged', (accounts) => {
  // Handle the new accounts, or lack thereof.
  // "accounts" will always be an array, but it can be empty.
});

SPC Chain.on('chainChanged', (chainId) => {
  // Handle the new chain.
  // Correctly handling chain changes can be complicated.
  // We recommend reloading the page unless you have a very good reason not to.
  window.location.reload();
});

connect

Please refer to MetaMask Doc, the only difference is we injected a different object.

interface ConnectInfo {
  chainId: string;
}

SPC Chain.on('connect', handler: (connectInfo: ConnectInfo) => void);

disconnect

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('disconnect', handler: (error: ProviderRpcError) => void);

accountsChanged

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('accountsChanged', handler: (accounts: Array<string>) => void);

chainChanged

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('chainChanged', handler: (chainId: string) => void);

SPC Chain.on('chainChanged', (_chainId) => window.location.reload());

message

Please refer to MetaMask Doc, the only difference is we injected a different object.

interface ProviderMessage {
  type: string;
  data: unknown;
}

SPC Chain.on('message', handler: (message: ProviderMessage) => void);

Errors

Please refer to MetaMask Doc, the only difference is we injected a different object.

Using the Provider

This snippet explains how to accomplish the three most common requirements for web3 sites:

Detect which SPC Chain network the user is connected to
Get the user's SPC Chain account(s)

/**********************************************************/
/* Handle chain (network) and chainChanged (per EIP-1193) */
/**********************************************************/

// Normally, we would recommend the 'eth_chainId' RPC method, but it currently
// returns incorrectly formatted chain ID values.
let currentChainId = SPC Chain.chainId;

SPC Chain.on('chainChanged', handleChainChanged);

function handleChainChanged(_chainId) {
  // We recommend reloading the page, unless you must do otherwise
  window.location.reload();
}

/***********************************************************/
/* Handle user accounts and accountsChanged (per EIP-1193) */
/***********************************************************/

let currentAccount = null;
SPC Chain
  .request({ method: 'eth_accounts' })
  .then(handleAccountsChanged)
  .catch((err) => {
    // Some unexpected error.
    // For backwards compatibility reasons, if no accounts are available,
    // eth_accounts will return an empty array.
    console.error(err);
  });

// Note that this event is emitted on page load.
// If the array of accounts is non-empty, you're already
// connected.
SPC Chain.on('accountsChanged', handleAccountsChanged);

// For now, 'eth_accounts' will continue to always return an array
function handleAccountsChanged(accounts) {
  if (accounts.length === 0) {
    // SPC Chain Wallet is locked or the user has not connected any accounts
    console.log('Please connect to SPC Chain Wallet.');
  } else if (accounts[0] !== currentAccount) {
    currentAccount = accounts[0];
    // Do any other work!
  }
}

/*********************************************/
/* Access the user's accounts (per EIP-1102) */
/*********************************************/

// You should only attempt to request the user's accounts in response to user
// interaction, such as a button click.
// Otherwise, you popup-spam the user like it's 1999.
// If you fail to retrieve the user's account(s), you should encourage the user
// to initiate the attempt.
document.getElementById('connectButton', connect);

function connect() {
  SPC Chain
    .request({ method: 'eth_requestAccounts' })
    .then(handleAccountsChanged)
    .catch((err) => {
      if (err.code === 4001) {
        // EIP-1193 userRejectedRequest error
        // If this happens, the user rejected the connection request.
        console.log('Please connect to MetaMask.');
      } else {
        console.error(err);
      }
    });
}

Legacy API

Warning

You should never rely on any of these methods, properties, or events in practice.

This section documents MetaMask's legacy provider API.

To be compatible with existing dApps that support MetaMask, SPC Chain Wallet implements them as well, but please don't rely on them. We may deprecate them soon in the future.

Legacy Properties

SPC Chain.networkVersion (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.selectedAddress (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

Legacy Methods

SPC Chain.enable() (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.sendAsync() (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

interface JsonRpcRequest {
  id: string | undefined;
  jsonrpc: '2.0';
  method: string;
  params?: Array<any>;
}

interface JsonRpcResponse {
  id: string | undefined;
  jsonrpc: '2.0';
  method: string;
  result?: unknown;
  error?: Error;
}

type JsonRpcCallback = (error: Error, response: JsonRpcResponse) => unknown;

SPC Chain.sendAsync(payload: JsonRpcRequest, callback: JsonRpcCallback): void;

SPC Chain.send() (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.send(
  methodOrPayload: string | JsonRpcRequest,
  paramsOrCallback: Array<unknown> | JsonRpcCallback,
): Promise<JsonRpcResponse> | void;

This method behaves unpredictably and should be avoided at all costs. It is essentially an overloaded version of SPC Chain.sendAsync().

SPC Chain.send() can be called in three different ways:

// 1.
SPC Chain.send(payload: JsonRpcRequest, callback: JsonRpcCallback): void;

// 2.
SPC Chain.send(method: string, params?: Array<unknown>): Promise<JsonRpcResponse>;

// 3.
SPC Chain.send(payload: JsonRpcRequest): unknown;

You can think of these signatures as follows:

This signature is exactly like SPC Chain.sendAsync()
This signature is like an async SPC Chain.sendAsync() with method and params as arguments, instead of a JSON-RPC payload and callback
This signature enables you to call the following RPC methods synchronously:
eth_accounts
eth_coinbase
eth_uninstallFilter
net_version

Legacy Events

close (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('close', handler: (error: Error) => void);

chainIdChanged (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('chainChanged', handler: (chainId: string) => void);

networkChanged (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('networkChanged', handler: (networkId: string) => void);

notification (DEPRECATED)

Please refer to MetaMask Doc, the only difference is we injected a different object.

SPC Chain.on('notification', handler: (payload: any) => void);