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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1answer
101 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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1answer
95 views

What is "selector" in ChainLink API call?

I am using the example from chainlink to call an API; however, I am not sure it does. function checkProof(string memory JobLocation, int job_id) public { Chainlink.Request memory req = ...
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1answer
441 views

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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1answer
141 views

Using Chainlink External Adapters doesn't return anything

Trying to use this Bitcoin Adapter But having some issues specifically with the copyPath argument and the callback arguments. For one, I would like to retrieve multiple parts of the JSON that is ...
2
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1answer
771 views

Implementing Chainlink Data in Truffle / Hardhat

What is the easiest way to connect with Chainlink so we can test our dApp locally. Do we have to run a local Chainlink node, or is there any workaround for getting the online data?
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1answer
295 views

Chainlink node not connecting to External Adapter

I'm trying to use the Chainlink External Adapter to connect my contract to Twitter but my node I'm running is seemingly not able to connect to the adapter at localhost:8080 even though the adapter ...
4
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1answer
407 views

Does Chainlink store Oracle response for a transaction somewhere on blockchain?

Lets consider an example of transaction lifecycle where a smart contract uses Oracle to get external data ETH/USD price feed that is changed in real-time. Transaction is executed during mining, so it ...
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2answers
669 views

Sending token with contract interaction in Remix

I'm aware of using the value field in Remix to include ETH with my function call transaction but is there a way to send another token with my transaction, for example, LINK? Additionally I would like ...
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0answers
55 views

Unable to get response back from chainlink node using truffle console

I am trying to fetch close prices of a property deployed on a server running on a chainlink node. Here's what a snippet from my contract (RealEstateAPIConsumer.sol) looks like : function ...
7
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1answer
2k views

How to import both VRFConsumerBase and ChainlinkClient in same contract

I would like to use 2 of the functionalities of Chainlink, One is VRF and another is making API requests. So I am importing two libraries together. ChainlinkClient.sol and VRFConsumerBase.sol Which ...
0
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1answer
337 views

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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1answer
72 views

Chainlink not updating variables in Ethereum Smart Contract

I am having a strange thing occuring on kovan network. I am running a smart contract calling my chainlink oracle to request some information. My chainlink oracle responds correctly with the expected ...
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2answers
2k views

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, ...
2
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1answer
2k views

Error on view function call {'code': -32015, 'data': 'Reverted 0x', 'message': 'VM execution error.'}

I have a view function I'm trying to call on the kovan network with the following code. (You'll need an RPC_URL for the kovan network.) The function is the Chainlink historical price view function. I ...
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1answer
98 views

Unsupported Protocol Scheme When Calling Chainlink Oracle

I have just deployed a smart contract that uses a get request from my chainlink oracle. In my contract it is called as shown below: Chainlink.Request memory request = buildChainlinkRequest(jobId, ...
4
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1answer
660 views

Chainlink import causing Truffle console to crash

Related issue on GitHub: https://github.com/trufflesuite/truffle/issues/3329 If I compile my contracts with truffle compile and then open the truffle console with truffle develop then this happens: ...
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2answers
1k views

How to convert address to string (for use in chainlink request)?

I'm a solidity beginner... This Chainlink.Request memory request = buildChainlinkRequest(clJobId, address(this), this.registerConfirm.selector); request.add("repo", msg.sender); says ...
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1answer
343 views

Chainlink wrong address [duplicate]

So I recently withdrew funds from binance to my wallet, unfortunately I input a digit wrong in the address and it’s gone elsewhere. Is it possible to recover these funds or the funds are completely ...
0
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1answer
367 views

TX failed - Bad instruction - Funds not back

I sent some $link amount but TX failed due to Bad instruction error. Tx is https://etherscan.io/tx/0xa45e443c8cf310dbe69ab725358ac2da20afde33442a55ed7df985fe6645057d Have read that failed transactions ...
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2answers
3k views

Generating random number in Solidity without Chainlink

Hello I'm well aware there are plenty of threads around discussing different methods. Just curious and wanted to ask directly here because feel like the situation might be different. Essentially I'm ...
4
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1answer
305 views

How is Chainlink decentralized? [closed]

I believe one of the main criticisms of chainlink is that it is not decentralized enough, adding more nodes would be a big step in a positive direction. When I pull data through a node, that node ...
5
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1answer
835 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 ...
2
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1answer
77 views

How is the volume for the currency pair accounted for on chainlink's reference data feed?

https://feeds.chain.link/ - link for reference. Let's take the LINK/USD feed for example: From my understanding, the aggregation contract fetches the price of LINK in USD from the node operators who ...
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0answers
74 views

How does chainlink solve the oracle problem? [closed]

I've heard a lot about Chainlink recently -- how Synthetix, Aave and other top Defipulse projects are using them. How exactly does Chainlink solve the oracle problem from a technical perspective?
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0answers
77 views

Advantage of Chainlink's VRF over commitment scheme chain

News Chainlink announced a randomness oracle via VRF: https://blog.chain.link/verifiable-random-functions-vrf-random-number-generation-rng-feature/. Question What is the advantage of an VRF over a ...
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1answer
54 views

Chainlink node error: BumpGasUntilSafe FindTxBy Attempt: record not found

I am currently testing sending requests to my Chainlink node on Ropsten. I am following the documentation for running a Chainlink node and all went well until. 40 BumpGasUntilSafe FindTxByAttempt: ...
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1answer
120 views

API Call in solidity: gas required exceeds allowance (8000029) or always failing transaction

I'm trying to make an API call in solidity. pragma solidity ^0.6.0; import "github.com/smartcontractkit/chainlink/evm-contracts/src/v0.6/ChainlinkClient.sol"; contract GetData is ChainlinkClient { ...
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1answer
904 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 ...
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0answers
107 views

Chainlink services are not supporting the privateFor transactions in Quorum/Kaleido

We are exploring Kaleido and Chainlink for one of our use cases. What we have done: We have created a network of Quorum/Raft nodes. We had setup the chainlink service for the network. We have setup ...
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1answer
281 views

How does specifying job parameters on Chainlink work?

I am trying to understand Chainlink, and I am running into a wall. I found this tutorial, which explains how I can create a job spec using JSON. The tutorial explains that you can specify the url, ...
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2answers
254 views

Chainlink Kaleido Contract compilation

I am trying to re-compile the ChainlinkEthPrice contract found in the Kaleido Sample Gallery here: https://kaleido-io.github.io/kaleido-samples-gallery/#/kaleido-samples-gallery/chainlink. Codes as ...
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2answers
536 views

Chainlink vs Oraclize [closed]

I am trying to choose between Chainlink vs Oraclize. Can anyone advise the difference between both solution? Nathan Aw

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