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20 votes

How to programmatically detect and accept ETH and ERC20 deposits

It'd probably go something like this: User wants to deposit a token to your exchange If it's the first time the user is depositing that token then this occurs: Generate a new wallet key/pair on the ...
Miguel Mota's user avatar
  • 5,183
14 votes
Accepted

Why are smart contract outputs different from ordinary transactions?

Here's an intuition. The simplest transaction in Ethereum costs 21000 gas and looks like this: {from: '0x from', to: '0x to', value: web3.toWei(1, "ether")} When you're depositing to the exchange, ...
eth's user avatar
  • 86k
14 votes

What is the difference between an exchange like Coinbase and a wallet like Jaxx, MEW, MetaMask?

Your ETH & tokens are on the blockchain, regardless of what service you use to access them. When you move them, you are sending them from one address on the blockchain to another. These are simply ...
tayvano's user avatar
  • 16k
13 votes
Accepted

Is it secure to read USD / ETH rate from exchanges directly without using price oracles?

TL;DR: It is not secure to read pricing information from an exchange or other protocol. Always use a decentralized oracle. You're setting yourself up to be hacked when building smart contracts. ...
Patrick Collins's user avatar
11 votes
Accepted

How many exchanges have delisted ETH as a result of the proposed post DAO hack Ethereum hardfork?

According to the long list of Ethereum exchanges found here: https://coinmarketcap.com/currencies/ethereum/#markets Cryptopia appears to be the only one that has announced that it will remove ...
Sam's user avatar
  • 368
9 votes
Accepted

Are funds returned if one transfers from an exchange to an invalid Ethereum address?

Depends on "how" invalid it is. If you send ether to a public address that does not exist (i.e. nobody has the private key for), assuming that the format of the address is correct (hex, correct ...
Raine Revere's user avatar
  • 3,610
9 votes
Accepted

Can I sell a portion of my DAO tokens on a market place?

After the creation period ends on May 28th, you will be able to send DAO Tokens, similar to how you send ETH. You can send your entire amount of DAO Tokens or just a portion of them. It should be ...
tayvano's user avatar
  • 16k
9 votes
Accepted

How to build an Ethereum hot wallet for an exchange

The most Ethereum friendly solution would be Create and deploy a controller smart contract. This co-ordinates that we have deterministic addresses for payment forwarded smart contracts. For each new ...
Mikko Ohtamaa's user avatar
8 votes

Sent ether from wallet to bittrex, 12 hours later no balance on bittrex

The first thing to check is whether the transaction shows up on a ether block explorer. Enter your bittrex deposit address in the search field in https://etherchain.org . If you see a balance,it may ...
BokkyPooBah's user avatar
  • 40.3k
8 votes

Coinbase and Kraken Transfer Costs

I see what happened. 1ETH was transferred: from 0x2bF0011e4da5a841CE9459c0995Bb2646c4f1D21 (coinbase) to 0xd08436533f63b1342fB89198F963acD8589657AE (intermediary address) with a gas cost of (21000 * ...
Adam Dossa's user avatar
  • 1,297
7 votes
Accepted

Why do token transfers sent to the Binance wallet cost very little gas?

My guess is that these transactions resulted in a zero token balance for the sender and started with a non-zero balance for the recipient. When you store a value, the gas cost varies: It costs 20,000 ...
user19510's user avatar
  • 28.1k
6 votes

How do I transfer funds from an exchange to a wallet I control?

Kraken Log in to your Kraken account. Click on the "Funding Tab" and then "Withdraw" and then at the bottom, "Ether (ETH)" Click the "+ Add address" button. ...
6 votes
Accepted

Which exchange should I trust to provide ether price in USD?

From where these exchanges get the current market price of ether? The price is dependent on what users are currently valuing ether at. The exchanges don't set the prices, nor get them from anywhere ...
Richard Horrocks's user avatar
6 votes
Accepted

How does EtherDelta work?

In this high level overview, the Etherboost team which is behind EtherDelta wrote: The EtherDelta smart contract allows you to deposit or withdraw Ether or any ERC-20 Ethereum token. If you go to ...
Tesa's user avatar
  • 2,269
6 votes

ICO crypto-currencies accepted during the sale: ETH, BTC, or even fiat?

Yes, ethereum smart contract can only accept ether. So if one wants to use Bitcoin to buy ethereum tokens, then you need to do something to let it happen. I have seen different approaches to this ...
Dmitriy Lezhnev's user avatar
6 votes
Accepted

What is DeFi decentralized finance?

Decentralized Finance (DeFi) is the movement that leverages decentralized networks to transform old financial products into trustless and transparent protocols that run without intermediaries. Some ...
Nick Sawinyh's user avatar
6 votes

Get Uniswap Exchange Rate of any Token with Web3

There is a more simple solution to pull the price straight from Blockchain the steps are as follow: Using the router contract call getAmountsOut(1.0, [token, WETH]) Using the router contract call ...
Enrique Ramos's user avatar
5 votes

How to programmatically detect and accept ETH and ERC20 deposits

I have the same thoughts about implementation. And I think that your proposed solution is good. But for both, ether and ERC20 tokens, I do not recommend monitoring the blockchain. For ether balance ...
Muhammad Altabba's user avatar
4 votes

How do I buy Ethereum with USD?

Use a good BTC/USD exchange like Circle or Coinbase which allow you to purchase the BTC. Then you can send the BTC to an ETH exchange like Poloniex or BTC Markets where you can buy Ethereum.
Jarvin's user avatar
  • 39
4 votes

How to handle ether deposits like exchanges do?

You have asked a number of questions in addition to your main question which was how to handle ether deposits. The main problem with what you are trying to grapple with is the double-spend issue. If ...
T9b's user avatar
  • 1,185
4 votes

How do I transfer funds from an exchange to a wallet I control?

Poloniex Login to your Poloniex account In the upper right, look for the “Balances” drop down: Click Deposits and Withdrawals Scroll down until you see ETH and click "Withdraw" over on ...
4 votes

What happens with DGD in an exchange?

This is an issue with tokens like DAOTokens and DGD Tokens right now - both in terms of how to obtain them (during the token sales) and in terms of storing them to collect rewards. The issue lies with ...
tayvano's user avatar
  • 16k
4 votes

Sent ether from wallet to bittrex, 12 hours later no balance on bittrex

So this problem just fixed itself after I waited a little longer, took about 48 hours to show up.
Toastslave's user avatar
4 votes
Accepted

Can you solo mine directly to an address you don't have the private key for?

Yes you can. You can set the mining beneficiary (aka etherbase or coinbase) to any address you want, even a one that nobody has a private key of.
Paweł Bylica's user avatar
4 votes
Accepted

How to transfer DAO from MyEtherWallet to Kraken? (DAOs transfer method)

Go to https://www.myetherwallet.com/#send-tokens. Enter your private key and unlock your wallet. Enter your Kraken address and the number of The DAO tokens you want to transfer. Ensure the "DAO" ...
BokkyPooBah's user avatar
  • 40.3k
4 votes
Accepted

When do transactions on an exchange appear on etherscan?

Your transaction will appear on etherscan once you withdraw your ethers (or DAO) tokens are withdrawn from Poloniex. The transaction will be from Poloniex's Ethereum account into your Ethereum account....
BokkyPooBah's user avatar
  • 40.3k
4 votes

How do exchanges work with Ethereum?

You can write javascript code to open accounts and start transactions to your cold wallet. Basically you install a Ethereum node (for now geth is the best alternative here) on your server and ...
Roland Kofler's user avatar
4 votes

Is it possible to create ICO crowdsale seamlessly accepting multiple assets?

This is only a partial answer to your question. One issue you would face is that deposits by people who buy your tokens with BTC or any other cryptocurrency besides ETH would have to be credited ...
Tesa's user avatar
  • 2,269
4 votes

How are some addresses known to belong to certain exchanges?

As @RobHitchens states, Etherscan maintains an address book. To populate the address book, Etherscan can do some sleuthing to figure things out (after all, Ethereum is only pseudonymous) and they have ...
lungj's user avatar
  • 6,680
4 votes

How do I know my gemini.com's wallet's public key?

I can think of two questions you might be asking: How do I know where to send ETH/BTC if I want to get it into my Gemini account? Gemini will give you an address to send coins. E.g., when logged in, ...
user19510's user avatar
  • 28.1k

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