“offline” blockchain querying library

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The following is a list of libraries from ProgrammableWeb's Library Directory that matched your search term. Although there many different interpretations of the word "library" among software developers, ProgrammableWeb adheres to a specific definition so as to clearly distinguish libraries from SDKs and frameworks in a way that will facilitate clean search results. In ProgrammableWeb's parlance, the term "library" is strictly used to describe a platform-specific software tool that, when installed, results in the provisioning a specific API. Conversely, SDKs are exclusively for consuming APIs and Frameworks are agnostic to specific APIs. If you think a library, SDK, API, or other asset is missing from our directory, be sure to check our

guidelines

for making contributions to...

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How to write chaincode for Hyperledger Fabric v0.6 using the Java language

You've probably heard about blockchain, but maybe you're not sure how it applies to you as a Java™ developer. This tutorial will clear up any confusion. In a step-by-step approach, I'll show you how to use the Hyperledger Fabric v0.6 to build, run, and execute smart contracts, or chaincode, written in the Java language. You'll install tools, define your local blockchain network, and finally, build and run a chaincode smart contract.

For an overview of blockchain, see "What is blockchain? A Primer on Distributed Ledger Technology" on the developerWorks blog.

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Prerequisites

For this tutorial, I'll assume that you have...

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The blockchain module within the 21 Bitcoin Library (two1.blockchain) allows you to receive data about transactions and blocks from a blockchain data provider, as well as submit new transactions to the provider for relay to the network and inclusion in new blocks.

The package is organized around an abstract base class. Users of 21 will want to use the TwentyOneProvider class to instantiate a connection to the default provider.

We will illustrate the use of the two1.blockchain module by showing how to get various blockchain parameters from a provider instance.

Initializing a provider

Start by importing the class and initializing a provider:

from two1.blockchain.twentyone_provider import TwentyOneProvider provider = TwentyOneProvider()

Get block height, balances, and transactions

Get the current block height, provided by the provider:

>>> provider.get_block_height() 386574

Get all of the transactions for a particular address:

>>>...
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A few months ago I was at the Berlin Blockchain awards, and it appears that ‘blockchain’ is the new buzzword that startups and tech-folk like to throw into everything, without completely understanding the concepts behind it.

Whether you believe that blockchain is just a new buzzword for the industry or a truly revolutionary technology, developers are often uncertain of how they can use the blockchain concept in their applications. Eris Industries’ solution might make this a bit easier.

Eris Industries packages blockchain and smart contract concepts to make them more usable and apply them to your project. The best projects for this sort of technology are ideas that need a form of decentralized trust and security.

In this article, I will create a demo application that is a library of names of privileged users for a hypothetical situation. In the final section of the tutorial, the application will let you change a name in the list and check the values.

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The world’s most popular bitcoin wallet is now more secure and easier to use than ever. Starting today, we will begin the process of rolling out a major update to our flagship consumer product.

We’ve been focused on three things to make this the best wallet for you:

#1. A simplified wallet recovery and backup feature to keep users firmly in control of their funds
#2. A new security center to help users take the necessary steps to secure their wallet
#3. The friendliest and simplest user experience of any bitcoin wallet

What happens now?

As an existing user, you can choose the old version, or log into the new wallet at which point you can upgrade. Right now this is voluntary, but eventually everyone will need to switch. All your funds will be safe and sound when you choose to update, and you’ll get a lot of new features including:

Custom funds management Dashboard with balance overview Did You Know tips for new users New...
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A wallet is a collection of accounts, and an account is a combination of an address and its associated private key.

A wallet is said to be an online wallet when it is connected to the Internet. For example, wallets stored in geth, any website/database, and so on are called online wallets. Online wallets are also called hot wallets, web wallets, hosted wallets, and so on. Online wallets are not recommended at least when storing large amounts of ether or storing ether for a long time because they are risky. Also, depending on where the wallet is stored, it may require trusting a third party.

For example, most of the popular wallet services store the private keys of the wallets with themselves and...

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Blockchain visualisation

About: Visualization of bitcoin transactions (unconfirmed ones).

Node size scale:
LEGEND: Green = input, Red = output, Yellow = input+output, Blue = transaction
NAVIGATION: mouse + scroll = pan/zoom, SPACE = run/pause
TODO: - auto remove transactions older then x min or verified - show transaction details on hover - connect disconect button - listen for a specyfic address and color it and display alert when present - render graph for specyfic address/transaction - categorise transactions (simple, payments, mixing etc ) Found this interesting :-) Please send some Satoshis here to keep me going:

1NGBYHnYYM1i4HZkLsoRy3oFB2DzqusCoU

This visualisation was possible thanks to blockchain.info api and vivagraph.js...

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Repo Description Stars Growth Blockchain.info Receive Payments API V2 Demos 140 ... 114 Blockchain.info Receive Payments API PHP Demo 93 NamecoinToBind is a php script that generates bind zones for .bit... 41 Mini framework for easy creating blockchain games 18 ...
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A small guide how to get the Blockchain from HTTP Download as offered from

Peerexplorer

1) Get Nxt. Download the zip from the latest Nxt Version: https://nxtforum.org/nrs-releases/

2) Unzip it. In the extraced folder, you will find a folder called "nxt".

3) Now, before you start Nxt, go to http://www.peerexplorer.com, browse to the bottom where you see a link "Download the Nxt blockchain".

4) Again, you will get a zip file, unzip it to find again a folder called "nxt" with another folder "nxt_db". Place the whole folder "nxt_db" into the (step 2) "nxt" folder.
(if there already is a nxt_db folder, delete it)

5) Run Nxt if you are on Windows run.bat or on linux run.sh

6) Open your favorite browser and guide it to: http://localhost:7876

That's it, maybe you are missing a day or some hours, which should be caught up within minutes.

Ps. If you find this useful, consider a donation to peerexplorer.com:...

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