Linked Questions
19 questions linked to/from What is a blockchain oracle?
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How to set dynamic buy and sell price for my token?
I have built a simple erc-20 token. I used the code given on ethereum.org code as a reference. There they have talked about setting the price of my token. But how do I set it dynamically, as in ...
CommunityBot
- 1
23
votes
2
answers
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Gas price in ETH unit
I am wondering if there's a website that provides the price of the standard gas limit (21000 Gas, transaction cost for sending ETH) in ETH unit.
I checked Ether.Fund site, but it provides the gas ...
- 8,395
19
votes
2
answers
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How to access external knowledge / data in a smart contract
let’s say a contract wants to execute on knowledge contained outside the blockchain (e.g. whats the price of gold, what was the avg windspeed in NYC, how many people moved to portland in the last ...
- 124
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0
answers
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Smart Contracts and BigchainDB
How can I access data stored in blockchain database like BigchainDB using a smart contract in Ethereum?
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1
answer
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How to pass NFT property value to smart contract
I have an NFT staking contract that issues rewards based on the property rarity of the NFT staked. The four property tiers are 1,2,3 and 4.
When a user clicks stakeNFT(tokenId, nftTier), I use the ...
5
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4
answers
5k
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Can I make 'wait n seconds' statement in solidity function? [duplicate]
I want to write a solidity function like
function func(uint n, parameters*) payable public {
""wait n seconds""
other statements
}
Is it possible? It seems that delay parameter in ...
- 11.2k
0
votes
0
answers
535
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How to get "dna" from the metadata file of a ERC721 token in Solidity
here is the context, I would like to be able to burn n ERC721 token based on the "dna" and the attributes "type" in the metadata (see below):
{
"dna": "602472F&...
- 25
10
votes
3
answers
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Flash loan security considerations and attacks
What do developers need to be aware of to make their contracts and systems safe against flash loans?
What do they have to think about and protect against?
- 299
0
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0
answers
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How do i get the price of an erc20 token from solidity smart contract [duplicate]
I'm building a dapp, i'm trying to get the erc20 token price in usd from my smart contract how do i go about this? this is very necessary as smart contracts cannot read from outside networks. I don't ...
- 30.6k
5
votes
3
answers
2k
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Can we use block hash as verifiable randomness for the off-chain lottery?
My team is writing a discord lottery bot, we want to use the block hash of some block in the future as a seed for the random generator.
We want to allow lottery participants to independently verify ...
- 11.2k
4
votes
1
answer
6k
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How to find out the rate of ETH in USD in the contract?
I have a function which can rate ETH in USD. How can I find out the rate of ETH in USD in automatic mode?
Can this be done in Solidty?
Or do I have to use a third-party language, for example, ...
5
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2
answers
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Is there a way to get the *current* price of ETH in solidity function?
Is it possible to get the current price of ETH in USD in a buyTokens function of a deployed solidity smart contract?
For instance, every time GETH starts up is determines the price of ETH during ...
1
vote
1
answer
990
views
Getting stock market data from API or other means?
I'm trying to make a contract that interacts with a market price or a market out come : e.g APPL drops below X or NFLX > Y ...
Is it possible in Solidity to call an external API during this ...
- 11.2k
1
vote
1
answer
613
views
Retrieve Uniswap tx data in my solidity smart contract
As the title says, I have my Solidity smart contract and I am trying to import in ti some public data from the Uniswap contract.
In particular I would like to have the tx data stored in my contract (...
- 11.2k
108
votes
7
answers
37k
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How can an Ethereum contract get data from a website?
What is the process/workflow behind the process where an Ethereum contract gets some data from a website?
- 11.2k