gmd-nodejs-sdk

Intro

• This is an SDK to interact with Coop Network Node.
• Main use is for local signing of transactions.
• Offers helper functions to easily call Coop Network node API.
• This SDK was initially designed for NodeJS. For running it in browser please see browser directory
  • please read browser/readme.md and browser/index.html example

Instructions

• To run tests:

  npm install
  npm run test

• To use in your NodeJS app:

  npm install gmd-nodejs-sdk

For browser usage please see browser directory readme.md and index.html example.

Examples on hot to call the GMD node API

• For a complete list of API endpoints and their exact parameters you can see them on any node in a browser at address /test (e.g. https://node.thecoopnetwork.io/test )
• All examples in this readme.txt can also be found and ran in test directory.

Wallet

    //generate a random passphrase of 12 words
    let passPhrase = Wallet.generatePassphrase(12);
    
    //generate a wallet from a passphrase
    //please note that wallet does not store the mnemonic passphrase, but only the generated private key and public key. Mnemonic passphrase cannot be recovered by using Wallet.
    let wallet = await Wallet.fromPassphrase(passPhrase);

    //Create encrypted JSON:
    let encryptedJSON = await Wallet.encryptedJSONFromPassPhrase(passPhrase, "password example 123@@!");
    //recover wallet from encrypted json:
    let wallet = await Wallet.fromEncryptedJSON(encryptedJSON, "password example 123@@!"); 

Provider

• Provider is the component that haddles all interaction with a remote GMD node. It extends the RemoteAPICaller class wich enables the calling of the REST API exposed by a node. Full list of REST API endpoints https://node.thecoopnetwork.io/test:
• Usage example:

    const provider = new Provider(new URL('https://node.thecoopnetwork.io:6877'));
    
    const params = { requestType: 'getTransactionsBulk', pageSize: 3, page: 0}
    const data = await provider.apiCall('get', paramsGetTransactions);
    console.log('List of latest 3 transactions: ' + JSON.stringify(data, null, 2));

• Getting the blockchain height:

    let blockNo = await provider.getBlockNumber();
    console.log('Blockchain height: ' + blockNo);

Transaction

• Transaction is an abstract class that models all blockcahin transactions performed on the Coop Network blockchain.
• Any transaction has 5 steps:
  1. Create request JSON
  2. Process request JSON to an unsigned transaction (remote API call to a node is necessary)
  3. Sign the unsigned transaction
  4. Broadcast the signed transaction (remote API call to a node is necessary)
  5. [Optional] Transaction is confirmed after the trasaction is written to the blockchain and at leat one block is written on top of the transaction block (remote API call to a node is necessary).

  • The state of the transaction can only go through each step in the specified order as the output of each step is the input for the next step.

  • Each step can be executed on different device as long as the output of the previous step is somehow transmited out-of-band (e.g. via QR code). This mechanism is usefull when signing happens on a mobile device. - None of the outputs of the described steps contain any secret so exposing a QR is a safe operation.

  • For now, only concrete implementation of Transaction is "SendMoney" class, but further transactions will be added in the future.

  • Example on how to use "SendMoney":

    provider = new Provider(new URL('https://node.coopnetwork.io:6877'));
    wallet = await Wallet.fromPassphrase('screen drawn leave power connect confidence liquid everytime wall either poet shook');
  
    transaction = SendMoney.createTransaction('GMD-43MP-76UW-L69N-ALW39', '10000', wallet.publicKey); // Step 1 - local
    await provider.createUnsignedTransaction(transaction); // Step 2 - remote call
    await wallet.signTransaction(transaction); // Step 3 - local call
    await provider.broadcastTransaction(transaction); // Step 4 - remote call