bitcoin-propagator

Access multiple bitcoin remote nodes APIs with one single call.

The Bitcoin Propagator implements an interface for several APIs and join all in the Propagator.

Propagator

Each method call, on a Propagator instance, makes a request on an API for the result, and if any request error occurr, it automatically tries the next API, and the next.

The multiple calls, when needed, are hidden from the user, that only receives a Promise that is resolved when a request is successful, of rejected if any are.

Network support

The Propagator has support for bitcoin testnet and mainnet.

Instantiating

The network must be given to the Propagator constructor.

const Propagator = require('bitcoin-propagator');
const propagator = new Propagator('testnet');

There are two options, timeout and attempts.

• timeout refers to the request timeout.
• ettempts refers to the number of attempts a method will try when it receives erros from all the APIS.

Methods

Every method returns promises. Below, return value will refer to the argument of the function for resolved promise.

Get unspent transactions

This method requires the address from where the unspent transactions are associated. The return value is the array of unspent transactions.

propagator.getUnspent(address)
  .then(unspent => {
    // ...
  })
  .catch(error => {
    // Handle error
  });

Broadcast a transaction

This method broadcast a transaction that must be passed serialized as argument. The return value is the transaction ID.

propagator.broadcast(transaction)
  .then(transactionId => {
    // ...
  })
  .catch(error => {
    // Handle error
  });

Get data from a transaction

This method returns the transaction data from the transaction with ID passed as argument.

propagator.getTransaction(transactionId)
  .then(transaction => {
    // ...
  })
  .catch(error => {
    // Handle error
  });

The return value has 3 attributes:

• data: The data stored in the OP_RETURN.
• time: The time of the transaction.
• confirmations: The number of confirmations the block has received.

{
  data: <string>,
  time: <Date>,
  confirmations: <int>
}

Example

const Propagator = require('bitcoin-propagator');

const propagator = new Propagator('testnet');
const address = ... // A valid address

// Get the unspent transactions from the address
propagator.getUnspent(address)
  // Received an array of unspent transactions
  .then(unspent => {
    // Create a transaction with the unspent transactions data
    const transaction = ...
    // Broadcast the serialized transaction
    return propagator.broadcast(transaction);
  })
  // Received the transaction ID
  .then(transactionId => {
    // Get the transaction data with the transactionId
    return propagator.getTransaction(transactionId);
  })
  // Received the transaction data
  .then(data => {
    // Do something with the transaction data
  })
  // Received error
  .catch(error => {
    // Handle error
  });