densmirnov/blockchain-pen

BlockchainPen it's an UI for writing messages to the blockchain.

Blockchain Pen

A Pen (and webapp) to write "eternal" messages into the Blockchain.

Use it on:

http://blockchainpen.com

Your message will be stored into a bitcoin transaction. You have to load some millibits in it to send a message to pay for the transaction fees.

The transaction cost is 0.1 mBTC (millibitcoin, that's 0.0001 BTC).

You can load the funds from your wallet / keychain software to the bitcoin account (address) that is shown on the right. Copy paste the address or scan the QR code, deposit your preferred amount. All the coins go to miners, BlockchainPen doesn't keep any key or bitcoins, the private key is generated locally in your browser via bitcore-lib, the transaction is done via Blockchain.info (get utxos) and Blockcypher APIs (pushtx).

Enjoy!

@makeovoid

More infos

how it works under the hood:

• uses blockchain.info to get balance and utxo (see npm module blockchain-info-api-basic)
• calculates balance in remaining message to write (instead of btc or mbtc)
• uses blockcypher api to broadcast the transaction (blockchain.info doesn't accepts op_return)
• generates an address using bitcore-lib clientside and saves it to localStorage
• signs thre transaction with bitcore and adds the message (OP_RETURN - bitcoin addData function)
• a very simple UI using zepto (jquery-like)

that's basically it!


enjoy!

For Developers:

download the source:

git clone https://github.com/makevoid/blockchain_pen_coffee

run it:

python -m SimpleHTTPServer 3000

open http://localhost:3000

Edits

run guard to compile the coffeescript files into js

yes,

run:

guard

Node

if you want to run pen_cli.coffee with nodejs

Get Coffee:

npm install -g coffee-script

run:

coffee pen_cli.coffee

Eternity Wall

You can use Blockchain Pen to write to EternityWall, just prepend EW in front of your message, and after confirmation it will be posted on EternityWall:

http://eternitywall.it

You can put an hashtag or something, and then search your messages afterwards: http://eternitywall.it/search?q=makevoid

Enjoy!!!