How to Participate in Ethereum ERC20 token ICO crowdsale

Learn how to use special crypto wallets to buy ICO tokens

Instructions for contributing to an Ethereum token crowdsale ICO

Please Note: These instructions are intended for tech-savvy and/or crypto-knowledgable users. Also note that those who do not have ETH to contribute may not be approved to buy sufficient ETH prior to a given ICO, as users are typically given very low limits or must wait weeks or months for approval for reasonable limits. This very problem is one of the main problems that Javvy will solve. However, prior to the full Javvy crypto solution launch, anyone who wishes to purchase tokens with CASH (e.g. national currency) must participate in the Javvy pre-ICO sale.

To participate in ERC20 token sales, a special type of crypto wallet is required. For your security, it is critical to choose a crypto wallet that has the proper support for the ERC20 token standard and has a private key/file which you control. You must never share your wallet private key with anyone, and you should keep a backup, in case your device is lost or stolen.

PLEASE NOTE THAT TRADITIONAL CRYPTOCURRENCY EXCHANGES WILL NOT WORK!!

YOU MUST USE AN ERC20 COMPATIBLE CRYPTO WALLET. FORTUNATELY, THE JAVVY WALLET IS COMPATIBLE.

NOTE: DO NOT SEND YOUR FUNDS BEFORE THE FUNDRAISER IS OPEN OR AFTER IT IS CLOSED!!

Steps to contribute to the token sale:

  1. Buy ETH (ether) using a traditional cryptocurrency exchange *
  2. Transfer ETH (ether) to an ERC20-compatible wallet (see below)
  3. Prepare a “Send” transaction with the correct data and gas limit values
  4. Send a deposit to the published token sale address

*Unfortunately, the Javvy solution/wallet does not yet support buy & sell functionality, which is what we are raising funds to develop fully. So contributors must use the frustrating and risky existing cryptocurrency exchanges, experiencing the pain and delays first-hand. In the meantime, you may buy Javvy tokens (JVY), with nearly any currency, during the pre-ICO that is currently LIVE (learn more). If the Javvy solution already existed, purchasing tokens in our ICO would be very simple. At least future ICOs will benefit greatly from those who participate in the Javvy ICO, so that we can bring this much needed solution to the world!

Setting an appropriate Ethereum fee or “gas limit”

Sending a transaction with ETH (Ethereum) requires a fee that is determined by the speed desired, current network load, and the technical difficulty of processing the operation. With Ethereum, that fee is called “gas”. Since ERC20 token sales are more complex than common ETH transactions, it is necessary to use more “gas” than normal (a.k.a. transaction maximum gas).

Setting the correct data for the ERC20 Smart Contract

The following information is required in order for the ICO Smart Contract to process the ICO deposit and issue the tokens back to your wallet address:

  • Address – Provided on the crowdsale deposit page.
  • Data – Some ICOs require additional data, which can differ for each user. If specific data requirements are not mentioned, then leave the data field empty.
  • Gas limit: 250000 – The number of ethers used to carry out the transaction are known as the “gas limit”, which is a relatively small amount of money.

Known Compatible Wallets

Naturally, we strongly recommend using the Javvy wallet for all ERC20-based ICO token sales. However, the following wallets should also be compatible with Ethereum tokens (ERC-20 standard):

  • Javvy Prototype Wallet (Desktop, iOS, & Android; when ready)
  • MyEtherWallet (no download needed)
  • MetaMask (Firefox and Chrome browser addon)
  • Mist (Desktop)
  • Parity (Desktop) – not recommended
  • imToken (iPhone)
  • imToken (Android)

Please contact us, if you find that our list is outdated!

Adding Custom ERC20 Tokens to a Compatible Wallet

Sign up with MyEtherWallet, create a new wallet, and be sure to backup your address and private key information.

Once the wallet is created and backed up, go to “View Wallet Info” or “Send Ether or Tokens”. Enter in your information to pull up the wallet, and then click “Add Custom Token”. Enter in the following token contract:

Address: 0x4fd6cbd10599c01f8ee4210f716688b3ec4fc472
Token Symbol: JVY
Decimals: 18

Once successful, it will likely auto-load, but when you next visit MyEtherWallet, you may have to click “Load Token Balances” to see the balance of JVY (or any other custom token you added).

Known Incompatible Wallets

NEVER USE THE FOLLOWING WALLETS FOR ICO TOKEN SALES!!

  • Any Bitcoin exchange (e.g. Coinbase, Kraken, Bitfinex, etc) *
  • Any Ethereum exchange
  • Jaxx
  • Exodus

*Uses NON Smart Contract Options that are not compatible with ERC20 ICO/token Smart Contracts.

TROUBLESHOOTING

Low gas limit
The transaction will be automatically rejected and refunded, if the gas limit value is set too low *
In this case, it will not show in the blockchain explorer (such as etherscan.io).

No data field set
If the data field is required but is not set or is incorrect, it will be automatically rejected and refunded *
However, this transaction will appear in the blockchain explorer with an error code like “invalid jump”.


*When contributing in an ICO, the biggest downside to setting too low “gas limit” is that the ICO may end before the transaction is refunded to allow a retry, so it is imperative to set a proper “gas limit” on the first attempt.