6 votes

Is there an API which allows to download source code of contracts?

The web3 JS API has a getCode function that allows you to access the bytecode of the contract - that was deployed to the blockchain at the given address. It should be possible to analyse this to ...
SteveJaxon's user avatar
  • 2,528
5 votes
Accepted

How future resilient is a chainlink price feed?

Pricing/Economics of Data Feeds The economics of Chainlink decentralized oracles are similar to Ethereum and other L1s. Chainlink Node operators are economically incentivized to run nodes as long as ...
ZeusLawyer's user avatar
5 votes

Is there an API which allows to download source code of contracts?

I have recently created an unoffical python library and scriptable cli for etherchain.org called pyetherchain that gives you access to submitted solidity contract source-code including (experimental) ...
tintin's user avatar
  • 275
5 votes
Accepted

Contracts as data feed?

Ultimately you're going to be relying on somebody to tell the truth, because somebody is going to have to be in charge of the thermometer. The information from the thermometer then needs to be ...
Edmund Edgar's user avatar
  • 16.9k
4 votes
Accepted

Is there a euro-ether data-feed to use in smart contracts

Edmund Edgar from Reality Keys here. Reality Keys provides signed data for ETH vs Euro (and various other currencies) which you can feed into a smart contract. This is what's powering EtherOpt, the ...
Edmund Edgar's user avatar
  • 16.9k
3 votes

Is there a euro-ether data-feed to use in smart contracts

you can use smartcontract.com to use any API (JSON) as the source of an oracle, so from there you can use it in any smart contract on ethereum network. https://smartcontract.com/
Shayan's user avatar
  • 895
2 votes
Accepted

How is The Graph a decentralised solution?

It is server-based and topologically similar to a caching strategy. A purist might disagree, but an argument can be made that it is perfectly fine to use any sort of caching strategy (e.g. etherscan)...
Rob Hitchens's user avatar
  • 55.2k
2 votes

Fetch data from blockchain public network

So this really depends on the contract, if the contract implemented a public method or a public state variable then it's possible for you to get the data. contract SimpleFetch { uint public ...
cappy's user avatar
  • 191
1 vote

How to get chainlink price feed data for my national currency?

Chainlink data feed not only provides price of multiple asset values in units of USD(like BTC/USD, ETH/USD) but also provides the price of multiple fiats in units of USD. If you want to implement &...
Frank Kong's user avatar
1 vote
Accepted

Can I deploy custom data feed?

The price data of a token in Chainlink's data feed is provided by multiple decentralized oracle nodes within the Chainlink DON(Decentralized Oracle Network). Therefore, before deploying any data feed ...
Frank Kong's user avatar
1 vote

Fetch Buy/Sell price of commodities in smart contract

For a smart contract to use the data, somebody needs to post the data on a blockchain. Either you or someone else. If you don't want to expose the price feed endpoint, then you need to post the ...
Mikko Ohtamaa's user avatar
1 vote

How future resilient is a chainlink price feed?

Of course you'll have to pay at some point even on big feeds. The big issue for any oracle provider is that it costs gas to push values to chain. Right now LINK just pays for pushing most values, ...
thefett's user avatar
  • 3,873
1 vote

What's the best way to perform a cross-currency price lookup on chainlink?

Correct, the best way to do it for an unsupported Chainlink Price Feeds pair is to get the price of both pairs in the same denomination (eg USD), then manually do the conversion yourself. Eg say you ...
Harry Papacharissiou's user avatar
1 vote

Can I get price feed information directly from ChainLink oracles rather than from the aggregated contract?

The main purpose of oracles is to allow smart contracts to communicate to the outside world, hence why you see most examples focusing on this. From where exactly are you trying to access this data ...
Harry Papacharissiou's user avatar
1 vote

How to connect a database to a contract/dapp?

It would help if you told us a bit more about what you're trying to achieve - why is your data split between the blockchain and your database? (I'm not saying this is the wrong thing to do, but the ...
Edmund Edgar's user avatar
  • 16.9k
1 vote

How to take a snapshot of addresses and balances of all normal addresses?

I think the OP means complete to the currently accepted last node that was mined a little while ago. One way would be to build your own explorer - run a geth node - attach a console and use the web3 ...
nowucca's user avatar
  • 11
1 vote
Accepted

Does an API standard for price feeds exist?

On the Ethereum Project under "Standardized Contract APIs", a small standard for feeds is defined. I do not know if it is the most widely used standard, though. This standard defines two required ...
Thorkil Værge's user avatar
1 vote

How does automatic selling and buying with the constantly flowing price work?

The idea is that instead of you personally setting the price, there would be one centralized price feed that your contract queries every time it needs to know the price. These largely don't exist, but ...
Tjaden Hess's user avatar
  • 37.1k
1 vote

Is there a euro-ether data-feed to use in smart contracts

Not sure about your specific use case, but have a look at http://microtick.com. The goal is to have a trustless data feed for Ethereum (for continuous data, i.e. free running - not a prediction ...
Mark Jackson's user avatar

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