steem-stream

A Node.js layer for Steem that allows you to watch for specific actions on the Steem blockchain.

Install

npm install steem-stream

Quick Usage

const { Streamer } = require('steem-stream');

const ss = new Streamer();

// Kickstart the streamer to watch the Steem blockchain
ss.start();

// Watch for all custom JSON operations
ss.onCustomJson((op, { sender, isSignedWithActiveKey }, blockNumber, blockId, prevBlockId, trxId, blockTime) => {
  // React to custom JSON operations
});

Configuration

The Streamer object can accept an object of configuration values which are all optional. However, some operations like transfering Steem Engine tokens or other operations on the blockchain that are not READ ONLY, will require the active key and/or posting keys supplied as well as a username.

The BLOCK_CHECK_INTERVAL value is how often to check for new blocks or in cases of error or falling behind, to poll for new blocks. It is advisable you keep this as the default 1000ms value which is one second. This allows you to account for situations where blocks fall behind the main block.

The BLOCKS_BEHIND_WARNING value is a numeric value of the number of blocks your API will fall behind from the master before warning to the console.

The CHAIN_ID value is only for Steem Engine related operations. The API_URL is the Steem API. If you want to enable debug mode, set to DEBUG_MODE to true. The configuration values and their defaults can be found here.

const options = {
  ACTIVE_KEY: '',
  POSTING_KEY: '',
  APP_NAME: 'steem-stream',
  USERNAME: '',
  LAST_BLOCK_NUMBER: 0,
  BLOCK_CHECK_INTERVAL: 1000,
  BLOCKS_BEHIND_WARNING: 25,
  CHAIN_ID: 'ssc-mainnet1',
  API_URL: 'https://api.steemit.com',
  DEBUG_MODE: false
}

const ss = new Streamer(options);

The configuration itself can also be overloaded using the setConfig method which allows you to pass one or more of the above configuration options, useful in situations where multiple keys might be used for issuing.

ss.setConfig({
  ACTIVE_KEY: 'newactivekey',
  USERNAME: 'newusername'
});

Streamer

The following subscription methods are read only methods, they allow you to react to certain Steem and Steem Engine events on the blockchain. You do not need to pass in any keys to use these methods as they're purely read only.

To use the following methods, you need to make sure you have started the streamer using the start method.

Watch for transfers

ss.onTransfer((op,blockNumber, blockId, prevBlockId, trxId, blockTime) => {

})

Watch for custom JSON operations

ss.onCustomJson((op, { sender, isSignedWithActiveKey }, blockNumber, blockId, prevBlockId, trxId, blockTime) => {
  
})

Watch for Steem Engine JSON operations

ss.onSscJson((contractName, contractAction, contractPayload, sender, op, blockNumber, blockId, prevBlockId, trxId, blockTime) => {
  
})

Watch for post operations

ss.onPost((op, blockNumber, blockId, prevBlockId, trxId, blockTime) => {

});

Watch for comment operations

ss.onComment((op, blockNumber, blockId, prevBlockId, trxId, blockTime) => {

});

Actions (active key)

All of the below methods require an active key has been supplied in the constructor above called ACTIVE_KEY. The methods below are all promised based, so you can await them or use then to confirm a successful result.

You are not required to start the streamer using the start method to call these methods.

const ss = new Streamer({
  ACTIVE_KEY: 'youractivekey'
});

Transfer Steem (STEEM or SBD)

transferSteemTokens(from, to, amount, symbol, memo = '') {

}

Transfer Steem Engine tokens

transferSteemEngineTokens(from, to, symbol, quantity, memo = '') {

}

Transfer Multiple Steem Engine tokens

The accounts array should contain one or more objects with the following keys:

{
  account: 'steemaccountname',
  amount: '2.00'
}

If the object does not contain an amount, you will need to supply a default amount to the function itself. By default the default amount if no value is supplied is '0'. If every object in the array has an amount specific, the default amount is ignored.

transferSteemEngineTokensMultiple(from, accounts = [], symbol, memo = '', amount = '0') {

}

Issue Steem Engine tokens

issueSteemEngineTokens(from, to, symbol, quantity, memo = '') {

}

Issue Multiple Steem Engine tokens

The accounts array should contain one or more objects with the following keys:

{
  account: 'steemaccountname',
  amount: '2.00'
}

If the object does not contain an amount, you will need to supply a default amount to the function itself. By default the default amount if no value is supplied is '0'. If every object in the array has an amount specific, the default amount is ignored.

issueSteemEngineTokensMultiple(from, to, symbol, quantity, memo = '', amount = '0') {

}

Permanently running with PM2

Simply copy the ecosystem.config.js file from this repository into your application, globally install pm2 via npm install pm2 -g and change the script value below to reflect the main file of your application.

ecosystem.config.js

module.exports = {
  apps: [
    {
      name: 'steem-stream',
      script: 'index.js',
      ignore_watch: ['node_modules'],
      env: {
        NODE_ENV: 'development'
      },
      env_production: {
        NODE_ENV: 'production'
      }
    }
  ]