Linked Questions
19 questions linked to/from Why can't contracts make API calls?
3
votes
0
answers
781
views
Can you make HTTP calls with Solidity? [duplicate]
I want to create a very close to random number generator for a smart contract which I would like to do HTTP calls to webservices to do. Is that able to be done with Solidity? I am just digging into ...
- 183
108
votes
7
answers
37k
views
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?
- 1,997
19
votes
2
answers
4k
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What advantages and disadvantages does Open Blockchain / Hyperledger / Fabric have over Ethereum?
Similar to this question about Ethereum and Bitcoin:
What advantages and disadvantages does Open Blockchain (OBC) have over Ethereum? What can you do with OBC that you simply cannot with Ethereum? ...
eth♦
- 85k
12
votes
2
answers
4k
views
Why do smart contract languages need to be deterministic?
I read somewhere that smart contract languages need to be deterministic. Why?
- 5,729
12
votes
1
answer
5k
views
What is a blockchain oracle?
What is a blockchain oracle for smart contracts? And why is it needed? I've seen a lot of posts about "how do oracles work", and "what is the oracle problem" but I don't understand ...
- 359
13
votes
3
answers
2k
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Smart contract consensus for dummies
I've read a few other questions/answers on smart contract consensus by nodes in the network, but I still don't understand the steps. Here's how I picture it:
Two parties might agree upon a smart ...
- 151
8
votes
3
answers
2k
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Reading Ethereum contract state variables
Is this assumption correct ?
There is absolutely no way an ethereum contract can send data to the external world. It can only modify its state variables (later stored in the new block)and send ...
- 121
5
votes
2
answers
7k
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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 ...
- 399
3
votes
2
answers
891
views
Can you make ajax requests in a Dapp?
Mist recently launched its Beta (0.8.0), you can call any website for getting the HTML and JS files. What happens if inside my Dapp I make a XMLHttpRequest?
- 2,299
7
votes
2
answers
713
views
Is it possible to invalidate a smart contract?
How can I invalidate a smart contract that has already been deployed? I might want to do so because of business reasons, and maybe beneficial network effects.
Is it possible to invalidate a smart ...
- 9,663
1
vote
1
answer
1k
views
How to make an API call in solidity using Chainlink?
I am following the documentation from the Chainlink site, and I am attempting to make an API call. The main issue is I'm not sure what "address" is referring too. I am using remix in solidity v0.6
...
- 35
5
votes
1
answer
382
views
Can you interact with other blockchains' tokens by using an Ethereum smart-contract?
Let's say that a dev has a public and private key of an address on another blockchain. He wants to create a smart-contract that can interacts with these coins, for moving them, for selling them, etc.
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- 221
1
vote
1
answer
509
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How can I build a smart Oracle of my own for a smart contract? [closed]
I need my smart contract to access data from some source. I want to build a smart Oracle in order to achieve this.
- 11
1
vote
2
answers
758
views
How to track incoming to smart contract transactions using web3js?
I've got one Ethereum smart contract which calls functions of the other one. How could I track these calls using web3js or some other tool if it is possible at all? I need it because I want to execute ...
1
vote
1
answer
349
views
How do you handle a non-deterministic change during smart contract execution?
I read the following E-SO post and also several threads on Ethereum/Solidity forums regarding smart contracts and external servers (anything involving a socket):
Why can't contracts make API ...
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