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Ethereum Alarm Service

Ethereum Alarm Clock

Ethereum Alarm Clock

While creating Alarm, I ran up against the problem of how to answer what seemed like a simple question. Initially, I setup my storage as a mapping of block number to a list of calls. This seemed sufficient until I realized that in order to find the next scheduled call, I'd have to iterate through the upcoming blocks one at a time, querying for whether there were calls scheduled. A few iterations and I settled on a tree structure. It seemed functionally the same using a linked list. Something about trees always feels elegant to me. Each node of the tree has a left and a right child. Anything left comes before the node, and anything right comes after. Simple right. It turns out that the tree implementation accounts for almost a third of the code. In the world of web apps, I'm used to having a database that I can query. It was so easy to take that for granted. Only now am I seeing what it looks like when you have to start an ecosystem from scratch. Today I released what I hope to be a step towards powerful queryable data storage for contracts. Grove implements a more generic version of the tree management code that was created for the Alarm service. It currently uses the AVL implementation of a self balancing binary tree. As nodes are added to it, the tree continues to rebalance itself such that all leaf nodes remain within one level of each other in terms of depth. Lookups, Insertions, and Deletions are all O(log n) both in average and the worst case scenarios where n is the number of nodes in the tree. Currently grove can query for the first node that is >, >=, <, <=, == a given value. I'm hoping it can be the first stepping stone towards contract APIs with powerful querying capabilities. And to eat my own dog food, the next release of Alarm will change over to using Gr Continue reading >>

Ethereum Alarm Clock | Hacker News

Ethereum Alarm Clock | Hacker News

While this site looks interesting enough and even the comments below sort of say the same thing. What is this? I mean really. I look at this site and think. I do not know what this is. And even worse there is nothing on the site that even remotely explains it. Why was it even posted? Its a cron system for decentralized apps. Since there's no way to run 'cron' trustlessly, this alarm clock creates an incentive to call functions at given time periods. Its one of those things that you need some background on Ethereum to understand, but if you understand Ethereum you know why something like could be the cornerstone of a lot of apps. A contract is a group of functions that live in the Ethereum Blockchain (a distributed virtual machine for running decentralized applications) > Why would people want one called periodically? For the same reason people need cron to call periodic functions. A contract is the term for an application that has been deployed on Ethereum. Contracts expose functions as an API that others can use to interact with them. > This contract creates a market which allows contracts to hire people to call them at the requested time. Does that mean that if 'market conditions' deteriorate or make it unfavorable to 'take the job' as it were, that the reliability of this system would take a hit? Executing a scheduled call is always profitable, so no. People would just make less money. The market aspect is more akin to a marketplace where people are hired to do a job. And the job is entirely automatable. Is there some world where demand for scheduled calls exceeds the market's capacity to execute them? And no one has the means or immediate liquidity to switch what they're doing to make a profit off that gap? I'm just thinking this is really loosely tied system, and Continue reading >>

Ethereum Alarm Clockreboot

Ethereum Alarm Clockreboot

A long long time ago I created a service named Ethereum Alarm Clock . This was my first project in the Ethereum ecosystem. For those of you who arent already familiar with it, the Alarm service is designed to allow scheduling of transactions for execution at a later time. I launched the first version of the service on September 22nd 2015. Over the next year, I worked heavily on the service, fixing various attack vectors, improving the contracts, and evolving the game theory for transaction scheduling. In September of 2016 I was ready to launch a completely rewritten set of smart contracts when the DOS attacks began. Since then, the service has languished. Other projects have been getting my attention and the Alarm service has sat dormant. ChronoLogic has generously taken up the torch to pay for the necessary development work to get the service back online. This includes allocating members of their development team to implement the necessary contract changes as well as a commitment to the future marketing of the Ethereum Alarm Clock. If all goes well, within a short period of time well be able to redeploy an updated set of smart contracts, reboot the service & build from there. You can see the pending changes and updates here as well as read more about this in ChronoLogics corresponding blog post explaining in a bit more detail the work being done. Ive had some preliminary conversations with wallet providers about integrating the Alarm service with their wallet interface. This would allow users to schedule things like ICO contributions, or really any transaction using a graphical interface. For the wallet provider, this can also serve as a stream of revenue since the Alarm service has support for attaching a small fee to each scheduled transaction, much like an affiliat Continue reading >>

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Schedule any contract function to be called a specified block number in the future. Fully implemented as an ethereum contract with no external services. Call execution can be done by anyone operating an ethereum node. No single point of failure. Contract code can be verified against the published source. Service implements no administrative functionality or special access to any address. The Alarm service does not implement suicide. You can count on it remaining available forever. The Alarm service is thoroughly documented with plenty of examples to help get you started. The Alarm service supports designation of certain addresses as authorized schedulers. Contracts can trust authorized calls were scheduled by an address that they authorized, allowing you to schedule calls to functions that would normally not be publicly callable. Anyone can execute scheduled calls, earning ether by doing so. Continue reading >>

Pipermerriam/ethereum-alarm-clock

Pipermerriam/ethereum-alarm-clock

I've tried to deploy a test contract, but it's not working. Could you see what I've done wrong ? I'm checking, but I think 0x1991313 is no longer correct. ok, not that, it's that you aren't sending along any ether with the call you can confirm this by checking the transaction logs and seeing if 0x513485fc is in the topics. That represents the CallRejected event. It will have a single piece of log data which if decoded to a bytes32 will be the "reason" the call was rejected. if you change the call to be alarm.call.value(5 ether)(0x1991313, address(this), sig, targetBlock); it should work. Also, be sure that you're sending on enough gas with the scheduling transaction. 1.5 million is a safe amount. Scheduling comes in at about 1 million Next, I'd suggest transitioning over to it's also on the testnet and it's the new version that I'm working on getting released Continue reading >>

Github - Ethereum-alarm-clock/ethereum-alarm-clock: Schedule Transactions For The Future

Github - Ethereum-alarm-clock/ethereum-alarm-clock: Schedule Transactions For The Future

Looking to download the DApp?: Latest Releases The Ethereum Alarm Clock is a smart contract protocol for scheduling Ethereum transactionsto be executed in the future. It allows any address to set the parameters of a transaction andallow executors (known as TimeNodes) to call these transactions during the desired window.The EAC is agnostic to callers so can be used by both human users and other smart contracts.Since all of the scheduling logic is contained in smart contracts, transactions can be scheduledfrom solidity, and developers can rely on it as a core piece of their smart contract of decentralized application. Additionally the EAC faciliates the execution of this pool of scheduled transactions through the TimeNode.The EAC TimeNode continuously runs and watches for transactions which are scheduled to be executed soonthen claims and later executes them. For the EAC to be successful it depends on users to run TimeNodes.There are a few ways incentives for running these TimeNodes are baked in to the protocol itself via the claimingmechanism and the bounty payout. See here for more information about how to run a TimeNode. Documentation can be found on Read the Docs . We are in progress of migrating the documentation to the Wiki . You can find the address for each network in the networks folder. Please see the cli repository for the commandline client. Please ensure you are using node version at least 8.0.0 and have truffle and ganache-cli installed. nvm use lts/carbonnpm inpm i -g [email protected] npm i -g ganache-cli Start ganache-cli in a terminal screen by running ganache-cli. In another terminal screen run npm test at the root of the directory. This will run the npm test script thatsplits up the tests into different runtimes. The tests are split because the EAC is a Continue reading >>

A Surge In The Value Of Crypto-currencies Provokes Alarm - New Kids On The Blockchain

A Surge In The Value Of Crypto-currencies Provokes Alarm - New Kids On The Blockchain

Bitcoin is the best known of these currencies, especially after hackers this month instructed victims to pay ransoms in the anonymous digital cash in order to get their computer files decrypted. Not that many bitcoins exist: there are about 16.3m of them, with only 1,800 new ones minted every day. But growing demand has pushed bitcoins price to a record recent high of about $1,830, up from $450 a year ago. Problems abide. Earlier this year some of the biggest exchanges, such as Bitfinex, experienced problems with their correspondent banks and were unable to pay out real-world currencies to account-holders. To get their money out, they had to buy bitcoin and exchange them elsewhere. Yet the market is becoming more mature: institutional investors, from family offices to hedge funds, have become more comfortable with crypto-currencies, says Mike Komaransky of Cumberland Mining, which arranges over-the-counter trades. Other factors driving demand include fluctuations of Chinas yuan, the French elections and, in a small way, the ransomware attack (when The Economist went to press, only about $80,000 had been sent to the bitcoin accounts held by the hackers). Counter-intuitively, bitcoins biggest weaknessthe systems limited capacityhas also increased demand for crypto-currencies. Its developers have argued for years about how to expand the system, which can only handle seven transactions per second, compared with thousands on conventional payment services. Even before worries surfaced that the currency could split in two over the disagreement, bitcoin holders started to diversify into some of the many other crypto-currencies, or alt.coins, to emerge in recent years. CoinMarketCap, a website, lists more than 800, from ArcticCoin, an obscure Russian currency, to ZCoin, which b Continue reading >>

Coinwink - Ethereum (eth) Price Alerts, Alarms, Reminders, Notifications

Coinwink - Ethereum (eth) Price Alerts, Alarms, Reminders, Notifications

Don't have an account? SIgn up, it's free. To start using SMS alerts service, please create an account. SMS alerts service is free, Coinwink does not charge anything. You will need to use your personal API key that you can get for free from Plivo or Nexmo. Required for USA and some other countries. Coinwink is not charging anything for SMS service, but you need to provide your own SMS API details. To get these, you need to sign up on Nexmo or Plivo service. The sign up is free and they give 2$ free SMS credit. The free credit works only with the single number that is linked to your Nexmo or Plivo account. For both Nexmo and Plivo, you will find your API details on the first page after you log in to your Nexmo or Plivo account. Enter these API details here and click Save button. Then you can start using SMS alerts service. Please enter details for at least one SMS service provider. You can also enter details for both. When sending alerts, Coinwink first checks Nexmo, if the service is not configured or unavailable, then it tries to use Plivo. In any case, Coinwink will always use only 1 service - the first one that's available. Coinwink cannot check if you entered the correct settings. If you are not sure, please create a test alert first. Coinwink is sending alerts every 3 minutes. For the USA you need to buy a virtual number in order to receive alerts. This can be done easily on Nexmo. You will then receive SMS alerts. For other countries there can be some other specific restrictions. If you do not receive alerts, please send and email to [email protected] and we will try to find a solution. For a quick step-by-step guide how to set up alerts (USA included), please see this Medium post . Coinwink is an open source, privacy-focused, cryptocurrency price alerts servi Continue reading >>

Blockchain - How Can A Contract Run Itself At A Later Time? - Ethereum Stack Exchange

Blockchain - How Can A Contract Run Itself At A Later Time? - Ethereum Stack Exchange

How can a contract run itself at a later time? In my blockchain application, I would like to have an event triggered at a later time, hours or perhaps even days after the application has most recently received a transaction from a user. How can I create an "event" that will trigger after a certain amount of time has passed? Disclaimer: I am the developer behind the Ethereum Alarm Clock service and I directly benefit from its usage. There are two fundamental ways of designing a contract to be called at a later time: lazy evaluation or eager evaluation. Lazy evaluation means that the contract's state will be updated only when needed. This often makes sense for contracts that naturally incentivise users to call them at a future date. An example of this might be a trust fund contract that will remain locked until someone's 18th birthday. This individual would be motivated to execute the dispersal of those funds at that time. A more complex example is an interest-bearing contract. Say I deposit 1 ETH, and every month I get 1% interest, compounding. The lazy way: When I want to withdraw my money, I call the contract and it calculates my balance, based on the interest rate, my last known balance, and the elapsed time. The eager way: I use the Ethereum Alarm Clock or some similar service to call the claimInterest() function of the contract, which calculates that month's interest and debits my balance. In this case, lazy evaluation makes sense, because it is easy to calculate the current state based on the past state and elapsed time. Eager evaluation is useful when state transitions are If the contract needs to accept input from or send transactions to another contract Call Scheduling with Ethereum Alarm Clock The Ethereum Alarm Clock service supports scheduling a contract to Continue reading >>

Ethereum Accounts, Address And Contracts

Ethereum Accounts, Address And Contracts

// Grove v0.2/// @title GroveLib - Library for queriable indexed ordered data./// @author PiperMerriam -library GroveLib { /* * Indexes for ordered data * * Address: 0x7c1eb207c07e7ab13cf245585bd03d0fa478d034 */ struct Index { bytes32 root; mapping (bytes32 => Node) nodes; } struct Node { bytes32 id; int value; bytes32 parent; bytes32 left; bytes32 right; uint height; } function max(uint a, uint b) internal returns (uint) { if (a >= b) { return a; } return b; } /* * Node getters */ /// @dev Retrieve the unique identifier for the node. /// @param index The index that the node is part of. /// @param id The id for the node to be looked up. function getNodeId(Index storage index, bytes32 id) constant returns (bytes32) { return index.nodes[id].id; } /// @dev Retrieve the value for the node. /// @param index The index that the node is part of. /// @param id The id for the node to be looked up. function getNodeValue(Index storage index, bytes32 id) constant returns (int) { return index.nodes[id].value; } /// @dev Retrieve the height of the node. /// @param index The index that the node is part of. /// @param id The id for the node to be looked up. function getNodeHeight(Index storage index, bytes32 id) constant returns (uint) { return index.nodes[id].height; } /// @dev Retrieve the parent id of the node. /// @param index The index that the node is part of. /// @param id The id for the node to be looked up. function getNodeParent(Index storage index, bytes32 id) constant returns (bytes32) { return index.nodes[id].parent; } /// @dev Retrieve the left child id of the node. /// @param index The index that the node is part of. /// @param id The id for the node to be looked up. function getNodeLeftChild(Index storage index, bytes32 id) constant returns (bytes32) { return index.node Continue reading >>

Announcing The Ethereum Alarm Clock & Chronologic Partnership

Announcing The Ethereum Alarm Clock & Chronologic Partnership

Announcing the Ethereum Alarm Clock & ChronoLogic Partnership Sponsorship of Time-related EthereumProjects ChronoLogic has solidified a partnership with & grant to Ethereum Alarm Clock ( ) as the first project that will benefit from ChronoLogic funding to support temporal innovation. Ethereum Alarm Clock currently allows scheduling of transactions for delayed execution at a specified block or time in the future. Use Case #1: Crypto project contribution periods (also know as ICOs) usually have a pre-defined time when they launch. Often times many potential contributors dont get in even though they have been supporting the community since the beginning because they miss the exact time. Ethereum Alarm Clock will solve this problem once fully developed & implemented. No longer will you have to sit in front of your computer waiting to push a button at exactly the right moment. You wont have to wake up in the middle of the night or stay up very late. Use Case #2: Scheduling ETH & token payments such as DAY token transfers in advance whether for HR or other use cases at a pre-defined time. There are dozens and dozens of other examples. Piper Presenting the Ethereum Alarm Clock at Devcon One Piper Merriam the creator of Ethereum Alarm Clock has worked on the project for a significant time and although his contributions to the Ethereum community have been immense, the decision to partner with ChronoLogic was to take the technology and figure out how to implement it into real world use cases & help on the marketing front to gain user traction from the ChronoLogic & crypto community. This is the initial work the ChronoLogic developers will do on the Ethereum Alarm Clock: Updating the existing smart contracts for the Ethereum Alarm Clock service to compile on one of the latest ver Continue reading >>

Welcome To Ethereum Alarm Clocks Documentation!

Welcome To Ethereum Alarm Clocks Documentation!

Welcome to Ethereum Alarm Clocks documentation! The Ethereum Alarm Clock is a service that allows scheduling transactions to beexecuted at a later time on the ethereum blockchain. This is accomplished byspecifying all of the details for the transaction you wish to send, as well asproviding up-front payment for gas costs, allowing your transaction to beexecuted for you at a later time. The service is completely trustless, meaning that the entire service operatesas smart contracts on the Ethereum blockchain, with no priviledged access givento any party. The code for this service is open source under the MIT license and can beviewed on the github repository . Each release of the alarm service includesdetails on verifying the contract source code. For a more complete explanation of what this service does check out the Introduction . If you are a smart contract developer and would like to start schedulingtransactions now then check out the Quickstart . If you are looking to build a lower level integration with the service then our Continue reading >>

Scheduling Ethereum Alarm Clock 1.0.0 Documentation

Scheduling Ethereum Alarm Clock 1.0.0 Documentation

Function calls are scheduled with the scheduleCall function on the Alarmservice. Solidity Function Signature: scheduleCall(address contractAddress, bytes4 signature, bytes32 dataHash, uint targetBlock, uint8 gracePeriod, uint nonce); The scheduleCall function takes the following parameters: address contractAddress: The contract address that the function should becalled on. bytes4 abiSignature: The 4 byte ABI function signature for the call. bytes32 dataHash: The sha3 hash of the call data for the call. uint targetBlock: The block number the call should be executed on. uint8 gracePeriod: The number of blocks after targetBlock that it isok to still execute this call. uint nonce: Number to allow for differentiating a call from another onewhich has the exact same information for all other user specified fields. Prior to scheduling a function call, any call data necessary for the call musthave already been registered. The scheduleCall function has two alternate invocation formats that can beused as well. Solidity Function Signature: scheduleCall(address contractAddress, bytes4 abiSignature, bytes32 dataHash, uint targetBlock, uint8 gracePeriod) public When invoked this way, the nonce argument is defaulted to 0. Solidity Function Signature: scheduleCall(address contractAddress, bytes4 abiSignature, bytes32 dataHash, uint256 targetBlock) public When invoked this way, the gracePeriod argument is defaulted to 255 andthen nonce set to 0. Contracts can take care of their own call scheduling. In this example Lottery contract, every time the beginLottery functionis called, a call to the pickWinner function is scheduled for approximately24 hours later (5760 blocks). Alternatively, calls can be scheduled to be executed on other contracts The Alarm service operates under a scheduler p 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 >>

Ethereum's Big Switch: The New Roadmap To Proof-of-stake - Coindesk

Ethereum's Big Switch: The New Roadmap To Proof-of-stake - Coindesk

Ethereum's Big Switch: The New Roadmap to Proof-of-Stake After years of development, ethereum has a new planto update the algorithm that keeps its entire network in sync. Vitalik Buterin, ethereum's creator , recently released a rough implementation guide that reveals the network's developers will first start with a 'hybrid' system that merges bitcoin-style proof-of-work mining with itsmuch-anticipated and still-experimental proof-of-stake system called Casper, created by Buterin. The planeffectively meansethereum will begin alternating between the two systems, so that some transaction blocks (one out of 100) are secured viaproof-of-stake and the rest remain on proof-of-work. Buterin has notably been working on his implementationin parallel with ethereum developer Vlad Zamfir, "cross-pollinating" their ideas. According toKarl Floersch, blockchain engineer for ethereum startup ConsenSysand a coder working with Buterin on Casper's development, the result is that the network is choosing the more conservative of two potential paths forward. "What Vitalik has come up with is a get-it-out-the-door, working version, that works, but might be less theoretically revolutionary than Vlad's." Because Buterin's implementation of Casper can, he thinks, get to production faster, it will be used in the first stage of ethereum's evolution. If implemented, this would be the first time proof-of-stake would be employed on the live ethereum platform, albeit playing a minor role. It also would a largereal-world test of proof-of-stake, enabling the cryptocurrency community to determine whether the proof algorithm is asuperior one, as proponents have argued. To advocates, the goal of this potentially revolutionary change to proof-of-stake is to reduce the electricityethereum requires to reacha Continue reading >>

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