Questions tagged [chainlink]

Chainlink is a decentralized oracle network that enables blockchain smart contracts to securely access off-chain data feeds.

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Rules on choosing a Solidity version

Is there a rule on using a specific solidity version? I mostly work with 0.8.7 and they sometimes conflict with some Chainlink or Open Zeppelin contracts since they use either v6 or v7. Should I ...
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10 votes
2 answers
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Is Chainlink's price reference data free to consume?

I was looking at feeds.chain.link and it's not immediately obvious if anyone can tap into all these price feeds without incurring a cost: For instance, I did find the ETH/USD aggregator contract, ...
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Brownie Chainlink Import Error VSCode - 'File import callback not supported'

The code seems to have successfully compiled, but VSCode keeps showing this error - "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol" not found. File import callback not ...
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5 votes
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What is the cost of using a Chainlink Oracle?

I use the market.link to check available jobs and each job has its own price in terms of link. My question is how many times this fee will be paid? For example: Let's say the API GET request costs 0....
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3 answers
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Issue with importing Chainlink & Openzeppelin

Currently trying to run a script and keep running into an error when trying to import chainlink and openzeppelin contracts. Not sure why, I looked at brownie pm list to make sure I have the correct ...
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1 vote
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730 views

Do all Chainlink feeds return prices with 8 decimals of precision?

It looks like many Chainlink feed aggregators have 8 decimals of precision: ETH/USD, which returns 140330173736 = $1,403.30173736 BTC/USD, which returns 3696759888474 = $36,967.59888474 I found the ...
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0 votes
1 answer
209 views

How to import deployed contract from rinkeby to browser blockchain remix

I saw a lot of tutorials on running the Rinkbey testnet injected using MetaMask on Remix to call functions such as to get conversion rates from Ether to USD using chainlink. I would like to do so ...
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How to build a decentralized bridge between two blockchains?

I am trying to build my own custom bridge between Ethereum and Binance Smart Chain so that people can transfer tokens and possibly some other assets from one chain to another and vice versa. For this ...
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3 votes
2 answers
708 views

price conversion using chainlink ETHUSD price

I'm storing a product's USD value in contract. mapping (string => uint256) productUSD; For example, if it's $52 I'd store it as productUSD[_product] = 52; Now, when people paying in ETH, I want to ...
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5 votes
2 answers
1k views

How to get all the historical data from chainlink price feeds?

I wanted to pull the historical data stored by the reference data contracts by chainlink oracles. Since all the data is on-chain, I should be able to view it all? But currently, my contract can only ...
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3 votes
1 answer
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How to return a Chainlink API Call to another contract?

I need to call a function that returns the uint value requested by the oracle from another contract function. I am trying the next... but I think I am going by the bad way. Any solution for that? The ...
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4 answers
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File outside of allowed directories on brownie compile command

trying to import to files from openzeppelin and chainlink in my contract file like so: import "@openzeppelin/contracts/token/ERC721/ERC721.sol"; import "@chainlink/contracts/src/v0.6/...
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2 votes
1 answer
154 views

How to pass argument to Chainlink selector?

I have a mapping with integer keys and struct values. mapping (int => Client) public customers; Each customer has its own proof argument which I am trying to update with a Chainlink API call. Here ...
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2 votes
1 answer
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Does Chainlink decimal change over time?

I am implementing Chainlink in my contract. Should I request the decimals() function periodically, or decimals are static, so I don't have to worry about any decimals change in a specific contract.
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fulfillRandomness in Chainlink VRF?

After executing the requestRandomness function function getRandomNumber(uint256 userProvidedSeed) public returns (bytes32 requestId) { require(LINK.balanceOf(address(this)) >= fee, "Not ...
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EthTx adapter in Chainlink job, fails with “transaction reverted on-chain”

I have gone through the existing error link EthTx Adapter in Chainlink Job and the solutions recommended is also tried, but still i am facing the same issue. Approach I taken to debug is given below ...
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EthTx adapter won't respond in Chainlink job, fails with "transaction reverted on-chain"

We're using the standard truffle box (https://github.com/smartcontractkit/box) to deploy Chainlink contract ($LINK definition, Oracle, sample end-user contract, etc) on a private Ethereum testnet. ...
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1 answer
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Are there Chainlink Contacts / Nodes for Ropsten?

I noticed on the official docs the networks are Mainnet Kovan Rinkeby Are there Chainlink Contacts / Nodes for Ropsten?
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Alternatives to get LINK tokens in Ropsten, for RNG

Sorry if this question sounds like very newbie (and maybe it is. I'm developing a Smart Contract which needs a random number generation, and after researching some time it seems that ChainLink VRF ...
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Minereum Lucky Draw claims 100% Safe randomness on a smart contract without oracles, is it really possible? [duplicate]

Is the way Minereum Lucky Draw game works really safe 100% onchain RNG and verifiable on smart contract? They claim yes but I would like to know expert technical answer for this, if so, isn't this a ...
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