snapquanow

Snapquanow

This MetaMask Snap is used to fetch or stream token pricing data from Aquanow.

Exposed RPC methods:

getTokenPrice:

This RPC method takes two string parameters, token and fiat, and returns the price of the token in the fiat currency selected. For the moment, the fiat currencies supported are USD and CAD. As an example, to get the price of ETH in USD:

const response = await ethereum.request({
  method: 'wallet_invokeSnap',
  params: ['npm:snapquanow', {
    method: 'getTokenPrice',
    params: {
      token: 'ETH',
      fiat: 'USD'
    }
  }]
})
alert(`The current ETH price in USD is ${response.price}`);

streamTokenPrice (experimental):

This RPC method is meant to be called from another Snap. It takes a token and fiat just like getTokenPrice, but additionally takes a callback parameter of the form {snapId, method}. It will then call your Snap's callback method repeatedly with the current price of the token, until your method returns false. Due to current limitations, this method can only be called from another Snap. Example:

// From the calling Snap:
const ensureSnapquanowIsInstalled = async () => {
  await wallet.request({
    method: 'wallet_enable',
    params: [
      {
        wallet_snap: {
          'npm:snapquanow': {},
        },
      },
    ],
  });
};

const callSnapquanow = async (method, params) => {
  await ensureSnapquanowIsInstalled();
  return wallet.request({
    method: 'wallet_invokeSnap',
    params: [
      'npm:snapquanow',
      {
        method,
        params,
      },
    ],
  });
};

module.exports.onRpcRequest = async ({ request }) => {
  switch (request.method) {
    case 'monitorEthereumPrice': {
      await callSnapquanow('streamTokenPrice', {
        token: 'ETH',
        fiat: 'USD',
        callback: {
          snapId: 'YOUR_SNAPS_ID',
          method: 'receiveEthereumPrice',
        },
      });

      return true;
    }
    case 'receiveEthereumPrice':
      console.log('Received ETH price', request.params);
      return true; // Keeps streaming forever. Use a more appropriate logic to decide when to stop streaming
    default:
      throw new Error('Method not found.');
  }
};