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Ethereum Web Api

Ethereum Developers Apis

Ethereum Developers Apis

[Beta] The Event Log API was designed to provide an alternative to the native eth_getLogs . Below are the list of supported filter parameters: topic0, topic1, topic2, topic3 (32 Bytes per topic) topic0_1_opr (and|or between topic0 & topic1), topic1_2_opr (and|or between topic1 & topic2), topic2_3_opr (and|or between topic2 & topic3), topic0_2_opr (and|or between topic0 & topic2) * fromBlock and toBlock accepts the blocknumber (integer, NOT hex) or 'latest' (earliest & pending is NOT supported yet) * Topic Operator (opr) choices are either 'and' or 'or' and are restricted to the above choices only * fromBlock and toBlock parameters are required * Either the address and/or topic(X) parameters are required, when multiple topic(X) parameters are used the topicX_X_opr (and|or operator) is also required * For performance & security considerations, only the first 1000 results are return. So please narrow down the filter parameters Here are some examples of how this filter maybe used: Get Event Logs from block number 379224 to 'latest' Block, where log address = 0x33990122638b9132ca29c723bdf037f1a891a70c and topic[0] = 0xf63780e752c6a54a94fc52715dbc5518a3b4c3c2833d301a204226548a2a8545 Makes a call or transaction, which won't be added to the blockchain and returns the used gas, which can be used for estimating the used gas [Beta] The WebSocket API allows developers to receive Real-Time notifications about new transactions. The Websocket Demo Page can be useful for seeing how this works. The following policies apply: * To keep the socket connection alive send a {"event":"ping"} every 20 seconds * Maximum number of 30 subscriptions per client * Maximum of 10 concurrent socket connections per/IP * After connecting to the socket you have to subscribe to an event within the next 60 Continue reading >>

Hacker News

Hacker News

This is great and potentially solves a challenge i'm having right now working with geth. However, I'm not comfortable sending private keys to your API end point. Do you guys have a solution to solve this concern? I'm sure others would probably feel the same... create a separate wallet on myEtherWallet and fund it with a little bit of eth to run the calls that you're making. you'd have to be stupid to send the private key of a wallet with a non-trivial amount of eth to an endpoint of a closed source, un-attributable API. which again limits the usefulness, imo. Thanks! The private key concern is sensible. Our plan is to open source the code and make the hosted version auditable in real time to prove the code being run is 'honest'. Bit of work to do on this, still. I'll post an update when we get there. Reminds me of BlockCypher- they pitch themselves as the "AWS" of blockchains [0], and released an Ethereum API not too long ago [1]. This looks interesting, but we're talking about money here. If you're looking for something similar to this consider a solid infrastructure provider first. We built an app on Coinbase's shoddy early API, only to have it go down in the middle of a YC interview -_- Yeah BlockCypher have made some useful tools. Especially for Bitcoin. We're going to focus just on Ethereum because there's a lot of developer tools/infrastructure missing right now. Think infrastructure as a service, webhooks, data transport etc. In the case of ETHEREST - it's just about being able to grab a contract address and call any method on it quickly and easily. Having to hook into a a node & provide an ABI gets frustrating really quickly, especially when you're testing. On stability - it's definitely an MVP right now. Our plan is to open source the innards soon to a) make s Continue reading >>

The Blockchain Explained To Web Developers, Part 2: In Practice

The Blockchain Explained To Web Developers, Part 2: In Practice

The Blockchain Explained to Web Developers, Part 2: In Practice Gildas Garcia & Kevin Maschtaler May 20, 2016 Is the blockchain a revolution? The technology that powers Bitcoin sure has the potential to disrupt the entire Internet, as we explained in a previous post . But how can you, a developer, use the blockchain to build applications? Are the tools easy to use, despite the complexity of the underlying concepts? How good is the developer experience? We wanted to find out, and there is no better tutorial than developing an app from scratch. So we've made a simple decentralized ad server called Zero Dollar Homepage, powered by blockchain. This is the story of our experience. Read on to learn how hard the blockchain is for developers today. Update (05/12/2017): This post is getting old and the blockchain technology is moving fast. The links to the Eris documentation are broken since Eris Industries was rebranded to Monax . The blockchain shines when it replaces intermediaries. We chose to focus on Ad Platforms, which are intermediaries between announcers (who buy visibility) and content providers (who sell screen real estate). Our project was to build a decentralized ad platform running on the blockchain. Since the famous Million Dollar Homepage experiment, innovating in the field of paid ads can't make you rich anymore. Instead, we chose to build a tool that allows to display ads for free - a Zero Dollar Homepage. For free, but not for nothing: advertisers exchange ad visibility for open-source contributions. So we've built a decentralized app to manage how ads display on a particular page. Advertisers need to take up a coding challenge to be able to put their ads on this page. In concrete terms, whenever we merge a Pull Request (PR) on one of marmelab's open-source r Continue reading >>

Dapps Ethereum Homestead 0.1 Documentation

Dapps Ethereum Homestead 0.1 Documentation

Swarm is a distributed storage platform and content distribution service, a native base layer service of the Ethereum web 3 stack. The primary objective of Swarm is to provide a sufficiently decentralized and redundant store of Ethereums public record, in particular to store and distribute dapp code and data as well as block chain data. From an economic point of view, it allows participants to efficiently pool their storage and bandwidth resources in order to provide the aforementioned services to all participants. From the end users perspective, Swarm is not that different from WWW, except that uploads are not to a specific server. The objective is to peer-to-peer storage and serving solution that is DDOS-resistant, zero-downtime, fault-tolerant and censorship-resistant as well as self-sustaining due to a built-in incentive system which uses peer to peer accounting and allows trading resources for payment. Swarm is designed to deeply integrate with the devp2p multiprotocol network layer of Ethereum as well as with the Ethereum blockchain for domain name resolution, service payments and content availability insurance. Continue reading >>

Getting Started As An Ethereum Web Developer

Getting Started As An Ethereum Web Developer

Ethereum developer at ConsenSys, co-founder of Getting Started as an Ethereum Web Developer UPDATE: I have created a repo for you to play around with that showcases most of the stuff covered in this article. I routinely build web applications that use Ethereum and I think I take for granted the amazing toolset that I use every day. Our ecosystem is growing rapidly and I think a lot of newcomers are feeling overwhelmed. Ethereum is an amazing technology, but it is also nascent and there simply hasnt been enough time for expertise to sufficiently permeate. I want people to know that Ethereum development is actually very compatible with modern web developer workflows its relatively easy to integrate Ethereum functionality into any web application, and you can start today. Because I fancy myself a champion of Ethereum on a mission to show mainstream developers the light, I have decided to put a bunch of scattered knowledge into one place (not very decentralized, I know). You will of course need to consult the proper documentation at each step, but my hope is that this article will show you how everything, more or less, fits together. If youre ready to learn, please let me be your spirit guide. Come join the Ethereum ecosystem and help us conquer the world. There are lots of clients to choose from, but I suggest not yet worrying about geth vs parity vs pyethapp (the up and coming python client represent!). For everyone who just wants a freaking blockchain so they can start building stuff (e.g. you), I suggest testrpc for all your development needs. Once you have it installed, you can start it with: Congratulations, you now have a blockchain. Note that by default testrpc does not mine blocks, but the -b flag allows you to specify a block interval (e.g. 1 second). I like this Continue reading >>

Javascript Api | Ethereum Builder's Guide

Javascript Api | Ethereum Builder's Guide

To make your app work with on Ethereum, you can use the web3 object provided by the web3.js library . Under the hood it communicates to a local node through RPC calls . web3.js works with AlethZero, geth and Mist, and also in an external browser if one of the former nodes are running locally. web3 contains the eth object - web3.eth (for specifically Ethereum blockchain interactions) and the shh object - web3.shh (for Whisper interaction). Over time we'll introduce other objects for each of the other web3 protocols. As this API is designed to work with a local RPC node and all its functions are by default use synchronous HTTP requests. If you want to make asynchronous request, you can pass an optional callback as the last parameter to most functions.All callbacks are using an error first callback style: web3.eth.getBlock(48, function(error, result){ if(!error) console.log(result) else console.error(error);}) You will always get a BigNumber object for balance values as JavaScript is not able to handle big numbers correctly.Look at the following examples: "101010100324325345346456456456456456456"// "101010100324325345346456456456456456456"101010100324325345346456456456456456456// 1.0101010032432535e+38 web3.js depends on the BigNumber Library and adds it automatically. var balance = new BigNumber('131242344353464564564574574567456');// or var balance = web3.eth.getBalance(someAddress);balance.plus(21).toString(10); // toString(10) converts it to a number string// "131242344353464564564574574567477" The next example wouldn't work as we have more than 20 floating points, therefore it is recommended to keep you balance always in wei and only transform it to other units when presenting to the user: var balance = new BigNumber('13124.234435346456466666457455567456');balance.pl Continue reading >>

Programming Ethereum Smart Contract Transactions In Javascript

Programming Ethereum Smart Contract Transactions In Javascript

Programming Ethereum smart contract transactions in JavaScript Programming Ethereum smart contract transactions in JavaScript By Mikko Ohtamaa 11 months ago. Tagged under web3 , ethereum , javascript , dapp , geth , parity , webpack , nodejs , solidity , solc . This a tutorial blog post and web application showing how to deploy an Ethereum smart contract and transacting with this contract from a web user interface. The web application written using JavaScript, React user interface library and Bootstrap theming. The application is coded in ECMAScript 2016 and wrapped together using Webpack module bundler. For the deployment of the contract Go Ethereum JSON-RPC API is used. The production web application communicates with Ethereum blockchain using Etherscan.io API service for pushing out transactions from the web application. All private keys are held 100% on the client side and transaction is constructed in JavaScript, making the example optimal to follow if you are working with non-custodian wallets or Dapps. We use both command line Node.js tools and browser based JavaScript in this demo. View the example application source code on Github . You need to be comfortable in advanced JavaScript programming. You need to have geth (Go-Ethereum) node or any Ethereum node software running in a Ethereum Ropsten testnet. See below how to install and connect to one safely. You need to be comfortable working on a command line in UNIXy environment, though Windows works also Interact with Ethereum blockchain over both Go-Ethereum JSON-RPC connection and EtherScan.io API Interact with smart contracts from web browser JavaScript Deploy a smart contract from a command line Generate private and public key pair offline Push transactions through etherscan.io API or optional sign tranactio Continue reading >>

Create A Hello World Contract In Ethereum

Create A Hello World Contract In Ethereum

Building a smart contract using the command line This page will help you build a Hello, World contract on the ethereum command line. If you don't know how to use the command line we recommend you skip this tutorial and instead build a Custom token using the graphical user interface . Smart contracts are account holding objects on the ethereum blockchain. They contain code functions and can interact with other contracts, make decisions, store data, and send ether to others. Contracts are defined by their creators, but their execution, and by extension the services they offer, is provided by the ethereum network itself. They will exist and be executable as long as the whole network exists, and will only disappear if they were programmed to self destruct. What can you do with contracts? Well, you can do almost anything really, but for our getting started guide let's do some simple things: To start you will create a classic "Hello World" contract, then you can build your own crypto token to send to whomever you like. Once you've mastered that then you will raise funds through a crowdfunding that, if successful, will supply a radically transparent and democratic organization that will only obey its own citizens, will never swerve away from its constitution and cannot be censored or shut down. And all that in less than 300 lines of code. Before you begin: Install the Ethereum CLI Learn more about contracts Please confirm that the GUI is closed before entering the geth console.Run geth to begin the sync process (this may take a while on the first run). Now that youve mastered the basics of Ethereum, lets move into your first serious contract. The Frontier is a big open territory and sometimes you might feel lonely, so our first order of business will be to create a little aut Continue reading >>

Ethereum For Web Developers

Ethereum For Web Developers

Techie, Foodie, Traveler, Founder www.zastrin.com I have been learning about Ethereum blockchain platform for some time and the more I learn, the more exciting it looks. There are lots of resources (articles, videos, platform documentation) about Ethereum, its easy to get overwhelmed. But, many of them are outdated understandably because the platform is still evolving at a rapid pace. It took me some time to piece together and get a complete picture of what Ethereum is and how it works. Talking to developers in meetup groups and other online communities, it feels like there are many people who would like to get their hands dirty with this new technology but have the same issue. This article is my attempt at explaining Ethereum from a web developers point of view. If you are a web developer, you know how a webapp with its client server architecture works at a very high level. You have your web application hosted on a hosting provider like AWS, Heroku or a VPS. All the clients interact with this one central application. Clients can be a browser, another api consuming your service etc. When a client makes a request to the server, the server does its magic, talks to the database and/or cache, reads/writes/updates the database and serves the client. This architecture works very well most of the times. However, there are certain applications where it would be really helpful if that database was publicly and securely accessible by everyone and you dont have to rely on this webapp owner for your data. For example, lets look at eBay. If you are a power seller who has earned hundreds of good reviews and for some reason eBay suspends your account. That would be very bad and could severely impact your business. What would be really nice is the ability for you take all your reviews Continue reading >>

Javascript Api Ethereum/wiki Wiki Github

Javascript Api Ethereum/wiki Wiki Github

First you need to get web3.js into your project. This can be done using the following methods: Then you need to create a web3 instance, setting a provider.To make sure you don't overwrite the already set provider when in mist, check first if the web3 is available: if (typeof web3 !== 'undefined') { web3 = new Web3(web3.currentProvider);} else { // set the provider you want from Web3.providers web3 = new Web3(new Web3.providers.HttpProvider("After that you can use the API of the web3 object. As this API is designed to work with a local RPC node, all its functions use synchronous HTTP requests by default. If you want to make an asynchronous request, you can pass an optional callback as the last parameter to most functions.All callbacks are using an error first callback style: web3.eth.getBlock(48, function(error, result){ if(!error) console.log(result) else console.error(error);}) Batch requests allow queuing up requests and processing them at once. Note Batch requests are not faster! In fact making many requests at once will in some cases be faster, as requests are processed asynchronously. Batch requests are mainly useful to ensure the serial processing of requests. var batch = web3.createBatch();batch.add(web3.eth.getBalance.request('0x0000000000000000000000000000000000000000', 'latest', callback));batch.add(web3.eth.contract(abi).at(address).balance.request(address, callback2));batch.execute(); You will always get a BigNumber object for number values as JavaScript is not able to handle big numbers correctly.Look at the following examples: "101010100324325345346456456456456456456"// "101010100324325345346456456456456456456"101010100324325345346456456456456456456// 1.0101010032432535e+38 web3.js depends on the BigNumber Library and adds it automatically. var balance = Continue reading >>

Bitgo Platform V2 Reference

Bitgo Platform V2 Reference

Multi-user workflows for use in enterprise environments If you are an existing (BitGo V1) API user, please refer to the V1 Integrator Notes for quick information on integrating BitGo platform V2 digital currencies. Legacy users may also refer to the V1 Bitcoin API , which is still available today. There is no dependency for developers to integrate with V1 or read the legacy documentation in order to take advantage of Platform V2. The primary advantage of multi-signature wallets is the ability for multiple machines and people to work together to approve a given transaction.Without multiple signatures on a transaction, all credentials to approve a transaction must reside with a single person on a machine.If that person or machine is compromised by an attacker, all funds can be taken with no recourse and no ability to audit the individual that invoked the key. BitGos multi-signature wallets allow you to keep control of your Bitcoin or other cryptocurrency despite introducing the concept of a co-signer. This allows enterprises to set up and maintain roles, policies, and rules on the wallet, making digital currency usable for businesses. For more information, please read the BitGo Whitepaper . To initialize your environment and authorize, use the following code: const BitGoJS = require('bitgo');// Read the user authentication section to get your API access tokenconst bitgo = new BitGoJS.BitGo({ env: 'test', accessToken: process.env.ACCESS_TOKEN });let coin = bitgo.coin('tbtc'); The BitGo web APIs provide developers with the capability to create and manage multi-signature wallets, manipulate their policies and interact with multiple digital currencies over a single robust interface.Several sensitive operations, such as the creation of user private keys and signing of transac Continue reading >>

Build Your First Ethereum Smart Contract With Soliditytutorial

Build Your First Ethereum Smart Contract With Soliditytutorial

Finance & Tech Nerd, Investor, Blockchain & Crypto Enthusiast, Wannabe Polymath, Master of Discipline in Training, Laissez Faire. Talk Is Cheap. Build Your First Ethereum Smart Contract with Solidity Tutorial So you wanna build a smart contract? Perhaps you want to understand how they work, maybe you want to build your own Dapp, maybe you want to launch the very first billion dollar ICO (sarcasm)... Regardless of your intentions, learning how smart contracts work is invaluable. The Ethereum platform possesses enormous potential to create Dapps that could change the way we interact on the web in the decades to come. While Ethereum deploys smart contracts that work much like a standard blockchain transaction, they yield a conditional statement that must be met before a function(s) is executed. Smart contracts can be used for voting, crowdfunding, blind auctions, multi-signature wallets and MUCH more. Bob has his own scrap metal depot business in the United States, Eric is his iron scrap supplier. Eric is based out of China. Bob and Eric have a GREAT business relationship. They trust each other and have been doing business for a long time. Both have booming businesses, and Bob in particular sells out of iron scrap on a routine basis. Bob deploys a contract where once his iron scrap inventory reaches a certain range, he automatically sends an order out to Eric for X lbs of iron scrap at Y ether per ton. Eric agrees to the arrangement and accepts Bobs payment in ether right away. Eric gets to work right away and starts fulfilling Bobs order. Eric can exchange his ether at a local exchange online for Yuan for a tiny fee and itll be processed instantaneously. Whether Eric decides to hold ether or convert to Yuan is his choice, but either way he can now put this capital to wor Continue reading >>

Top 11 Blockchain Apis For Web Developers

Top 11 Blockchain Apis For Web Developers

With online stores all over the world continuing to adopt Bitcoin and cryptocurrency payments, knowing which dedicated Blockchain API to use is important. Blockchain APIs allow e-commerce owners and stores to save time and money in the developing of payment systems from scratch and this allows them to focus on more significant and essential things to improve their service. Blockstrap API was introduced by Neurowave to serve web-developers and programmers. It helps them to create cryptocurrency-related web-applications that are compatible with HTML5 when working with Bitcoin and other digital assets. It accepts data from and is compatible with SoChain, Hello!, Block and Blockr APIs sources in addition to using its own data source. Neurowave does help organizations to integrate existing legacy systems with new distributed ledger technology when a company wants to use blockchain in its business. For instance, they work with large central banks, national regulators, telecommunication providers and licensed equity crowdfunding institutions in Malaysia and Singapore. They also provide training, consulting and hosting. Chain Core is based on Chain Protocol and is an enterprise-grade software for issuing and transferring financial assets on blockchain. With Chain Core, institutions can launch and operate a network on the blockchain or connect to already existing networks. The transfer is done while maintaining the governance standards, scalability, and privacy required in financial markets. It allows for management and transfer of different types of assets on the blockchain including currencies, securities, derivatives, gift cards, and loyalty points. For instance, banks and other financial institutions can employ this to move money internationally more quickly, transfer secur Continue reading >>

Oraclize Documentation

Oraclize Documentation

Welcome to the Documentation of Oraclize! The documentation is divided in the following sections: Background : the rationale behind the Oraclizes Oracle Model General Concepts : the main concepts behind Oraclize Data-Sources : information regarding the types of data sources Oraclize supports Integrations : how to integrate a blockchain application with Oraclize Development Tools : a list of tools to aide development of Oraclize-integrated smart contracts Security Deep Dive : how Oraclizes Authenticity proofs works Pricing : information on our pricing model for production uses Oraclize is the leading oracle service for smart contracts and blockchain applications, serving thousands of requests for day every day on Ethereum, Bitcoin and Rootstock. In the blockchain space, an oracle is a party which provides data. The need for such figure arise from the fact that blockchain applications, such as Bitcoin scripts and smart contracts cannot access and fetch directly the data they require: price feeds for assets and financial applications; weather-related informations for peer-to-peer insurance; random number generation for gambling. But to rely on a new trusted intermediary, the oracle in this case, it would be betraying the security and reduced-trust model of blockchain applications: which is what makes them interesting and useful in first place. One solution is to accept data inputs from more than one untrusted or partially trusted party and then execute the data-dependent action only after a number of them have provided the same answer or an answer within some constrains. This type of system can be considered a decentralized oracle system. Unfortunately, this approach has severe limitations: It requires a predefined standard on data format It is inherently inefficient: all Continue reading >>

Bitcoin Price Index Api - Coindesk

Bitcoin Price Index Api - Coindesk

CoinDesk Launches 2017 Year in Review Opinion and Analysis Series CoinDesk provides a simple API to make its Bitcoin Price Index (BPI) data programmatically available to others.You are free to use this API to include our data in any application or website as you see fit, as long as eachpage or app that uses it includes the text Powered by CoinDesk , linking to our price page.CoinDesk data is made available through a number of HTTP resources, and data is returned in JSON format.Please do not abuse our service. On the CoinDesk website, we publish the BPI in USD, EUR, and GBP, calculated every minute, based on criteria as discussed on the CoinDesk BPI page .This same data can be retrieved using the endpoint: {"time":{"updated":"Dec 14, 2017 11:12:00 UTC","updatedISO":"2017-12-14T11:12:00+00:00","updateduk":"Dec 14, 2017 at 11:12 GMT"},"disclaimer":"This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org","chartName":"Bitcoin","bpi":{"USD":{"code":"USD","symbol":"$","rate":"16,628.4075","description":"United States Dollar","rate_float":16628.4075},"GBP":{"code":"GBP","symbol":"","rate":"12,370.1717","description":"British Pound Sterling","rate_float":12370.1717},"EUR":{"code":"EUR","symbol":"","rate":"14,051.1041","description":"Euro","rate_float":14051.1041}}} We also offer the BPI converted into in any of our supported currencies . This data can be accessed using the endpoint: Where should be replaced by a valid ISO 4217 currency code as per our supported currency list . Sample RequestJSON Response {"time":{"updated":"Sep 18, 2013 17:27:00 UTC","updatedISO":"2013-09-18T17:27:00+00:00"},"disclaimer":"This data was produced from the CoinDesk Bitcoin Price Index. Non-U Continue reading >>

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