是否需要运行比特币节点才能与比特币区块链进行交互？

Question

Was looking at libraries for bitcoin node implementation like bitcoin-ruby and toshi . I guess my question is quite basic but I'm a newby here: Is it necessary to download the entire blockchain (and even set a node) in order interact with it as sending/receiving transactions, getting block data or create an address?

Answer 1

Things you can do offline, without syncing fully with the blockchain

• Create new bitcoin addresses
• Create transactions to be sent if you already have funds in some of your addresses

Things you can do with a connected, without syncing fully with the blockchain -

• Send a transaction (broadcast it)

Check out implementations of SPV wallets such as breadwallet to know more.

Answer 2

It is possible to interact with the bitcoin network without downloading the entire blockchain.

You should check how to interact with the peers in the bitcoin developer guide p2p section .

There are also a lot of libraries that allow you to interact with the bitcoin network, for example, with bitcore p2p you can interact with a pool of peers with:

var Pool = require('bitcore-p2p').Pool;
var Networks = require('bitcore-lib').Networks;

var pool = new Pool({network: Networks.livenet});

// connect to the network
pool.connect();

// attach peer events
pool.on('peerinv', function(peer, message) {
  // a new peer message has arrived
});

// Send a message, as soon as the response arrives, the pool will emit the related event.
// If your request is a getheaders message https://en.bitcoin.it/wiki/Protocol_documentation#getheaders
// you should listen for 'peerheaders'
pool.sendMessage(message)

// will disconnect all peers
pool.disconnect()

For checking an address balance, if you don't download the entire blockchain, you should download the header chain . When you want to check if an address is or not in a block, you can request a merkleblock .

Here and here you can find more about the spv clients.