js-digitalbits-wallets

A library to make it easier to write your own DigitalBits wallets.

It provides straightforward APIs for handling these tasks:

• Fetching and formatting data from the DigitalBits network
• Encrypting and storing secret keys
• Transferring funds to and from the DigitalBits network

Some things the library will try to do well:

• Useful type definitions
• Consistent, descriptive names
• Do rote tasks automatically for the user
• Provide one obvious, streamlined way of accomplishing each task

This is not an attempt to replace @digitalbits-blockchain/xdb-digitalbits-sdk, it's meant to provide a better API in some areas (data-fetching, transfers) and new functionality in others (key management).

Fetching and formatting data

Our library's goal is to provide typed, consistently-named DigitalBits data through a consistent, predictable API.

Note that our goal was to name data properties to be internally consistent and intuitive, not to be perfectly consistent with Frontier's responses. In some cases (particularly around offer / trade history), properties were renamed for clarity.

import {
  getTokenIdentifier,
  getBalanceIdentifier,
  DataProvider
} from "@digitalbits-blockchain/digitalbits-wallet-sdk";

// You'll use your DataProvider instance to ask for data from DigitalBits.
const dataProvider = new DataProvider({
  serverUrl: "https://frontier.livenet.digitalbits.io",
  accountOrKey: "<<Insert public key>>"
});

// Some class functions will fetch data directly.
const offers = await dataProvider.fetchOpenOffers({
  limit: 20,
  order: "desc"
});

// Others will watch the network for changes and invoke callback when it happens.
dataProvider.watchAccountDetails({
  onMessage: accountDetails => {
    console.log("Latest account details: ", accountDetails);
  },
  onError: err => {
    console.log("error: ", err);
  }
});

Encrypting and storing secret keys

Our KeyManager class allows you to securely encrypt keys client-side so you're never sending sensitive information (the user's key or password) over the wire in a raw state.

import {
  KeyManager,
  KeyManagerPlugins,
  KeyType
} from "@digitalbits-blockchain/digitalbits-wallet-sdk";

// To instantiate a keyManager instance, pass it an object that conforms to
// the KeyStore interface.
const keyManager = new KeyManager({
  // The library comes with a sample KeyStore that stores keys in memory.
  keyStore: new KeyManagerPlugins.MemoryKeyStore()
});

// Then, you need to register an encrypter to handle encrypting / decrypting keys.
// The library comes with two samples. (Don't use the Identity Encrypter in prod!)
keyManager.registerEncrypter(KeyManagerPlugins.ScryptEncrypter);

// If you're writing a production wallet, you'll probably want to write your own
// KeyStore and/or Encrypter. Make sure they conform to the `KeyStore` and
// `Encrypter` interfaces defined in these docs. You can use the `PluginTesting`
// functions to make sure that your plugins meet spec!

this.state.keyManager
  .storeKey({
    // The KeyManager takes keys that conform to our Key interface.
    key: {
      type: KeyType.plaintextKey,
      publicKey: "<<Insert public key>>",
      privateKey: "<<Insert private key>>"
    },

    password: "hunter2",
    encrypterName: KeyManagerPlugins.ScryptEncrypter.name
  })
  .then(keyMetadata => {
    console.log("Successfully encrypted and stored key: ", keyMetadata);
  })
  .catch(e => {
    console.log("Error saving key: ", e.toString());
  });

Transferring funds

Like the rest of the @digitalbits-blockchain/digitalbits-wallet-sdk, the Transfers API is meant to provide a predictable, easy-to-use interface.

import {
  DepositProvider,
  WithdrawProvider,
  getKycUrl,
  TransferResultType
} from "@digitalbits-blockchain/digitalbits-wallet-sdk";

const withdrawProvider = new WithdrawProvider("<<Insert transfer server URL>>");

const supportedAssets = await withdrawProvider.fetchSupportedAssets();

console.log("This withdraw server supports these assets: ", supportedAssets);

const fee = await withdrawProvider.fetchFinalFee({
  assetCode: "<<Asset code>>",
  amount: "888.8",
  type: "<<Type comes from the supportedAssets list>>"
});

console.log("You will be charged a fee of ", fee, "of <<Asset code>>");

const withdrawResult = await withdrawProvider.withdraw({
  assetCode: "<<Asset code>>",
  amount: "888.8",
  type: "<<Type comes from the supportedAssets list>>",
  destination: "<<Withdrawal destination key>>"
});

switch (withdrawResult.type) {
  case TransferResultType.ok:
    // The withdraw request succeeded, so submit a payment to the network.
    // makePayment(withdrawResult);
    break;
  case TransferResultType.interactiveKyc:
    if (isBrowser) {
      // To avoid popup blockers, the new window has to be opened directly in
      // response to a user click event, so we need consumers to provide us a
      // window instance that they created previously. This could also be done in
      // an iframe or something.
      const popup = window.open("", "name", "dimensions etc");

      const kycResult = await withdrawProvider.fetchKycInBrowser({
        response: withdrawResult,
        window: popup
      });

      // if deposit
      MyApp.showMessage(kycResult);

      // if withdraw, need to sign/submit transaction
      // (submitPayment is a placeholder function)
      MyApp.submitPayment({
        memo: kycResult.memo,
        destination: kycResult.accountId,
        amount
      });
    } else if (isServerEnv || isNativeEnv) {
      const kycRedirect = getKycUrl({
        result: withdrawResult,
        request: withdrawRequest,
        callbackUrl
      });
      /**
       * On e.g. react native, the client will have to open a webview manually
       * and pass a callback URL that the app has "claimed." This is very similar
       * to e.g. OAuth flows.
       * https://www.oauth.com/oauth2-servers/redirect-uris/redirect-uris-native-apps/
       * Include the original request so it can be provided as a querystring to
       * the callback URL. Simplifies re-submission dramatically after receiving
       * KYC results.
       */
    }
    break;
  case TransferResultType.nonInteractiveKyc:
    // TODO: SEP-12 data submission
    break;
  case TransferResultType.kycStatus:
    // The KYC information was previously submitted, but hasn't been approved
    // yet. Should show the user the pending status and any supplemental
    // information returned
    break;
  default:
  // There was an error.
}