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Questions tagged [oracles]

Oracle is a way of implementing a Smart Contract. Instead of running the contract code directly on the blockchain, the code is executed on some special off-chain entities called oracles which then send the result of the code to the blockchain network with a signature.

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1 answer
20 views

I need the address of the oracle service that provides football match results and related pricing information

I am a blockchain developer, and I am currently working on a football betting project. I have completed the development of the relevant contracts on Ethereum. Now, I need an oracle service that ...
0 votes
2 answers
108 views

Facing issues while running Chainlink node on XRPL EVM Sidechain network

Basically, I’m trying to run a Chainlink node on XRPL EVM Sidechain network. Here's the content of the config.toml file that I'm using: [Log] Level = 'warn' [WebServer] AllowOrigins = '\*' ...
0 votes
2 answers
883 views

Get market cap or current total supply of a specific coin (BTC, ETH, BNB etc)

I want to get a market cap of some specific coin (BTC, ETH, DOT, BNB etc) from an Ethereum smart contract written in Solidity. Market cap is obviously = price * current supply I can use an oracle like ...
1 vote
1 answer
1k views

Make a GET Request over the Binance Smart Chain with a Chainlink Oracle

I am trying to call to an BSC Oracle to make an HTTP request according this ChainLink example. In my example I am goin to use the BSC mainnet 56 and a other JobID obviously: My steps: I created the ...
1 vote
2 answers
370 views

How to use fiat exchange rate oracle in DAPP?

my team is trying to develop a DAPP about fiat exchange rate. How to get the latest fiat exchange rate (USD/EURO etc.) accurately from external Oracles(Or are there better ways doing this)?
0 votes
0 answers
15 views

Is it possible to get external data directly from function parameters in solidity?

Blockchain fetches external data through Oracle. Is it possible for a user calling a smart contract function to upload external data as parameters to the smart contract when calling the function?
1 vote
0 answers
23 views

Observations in TWAP Uniswap

In Uniswap v3's TWAP oracle, how often are observations stored in the observations array of each pool (assuming the array's cardinality has been increased several times already)? Is it on every swap? ...
2 votes
1 answer
777 views

Chainlink: how to get an array of random numbers?

I'm using Chainlink VRF and its function to get an array of random numbers: function expand(uint256 randomValue, uint256 n) public pure returns (uint256[] memory expandedValues) { expandedValues = ...
1 vote
2 answers
733 views

Retrieve and store data into a local database using smart contract

For my information oraclize can be use to retrieve data from several data source but what if i need to get from a local database such as oracle,sql, etc. Is there any way of doing it? PS: I am ...
3 votes
1 answer
5k views

What is best approach for generating random NFTs?

I am thinking of developing small DApp where user would collect cards (NFT). Each card would have some image and value associated with it. User collects cards by purchasing Pack of Five Cards which ...
1 vote
1 answer
104 views

Chainlink Oracle to call API

I have quite some question regarding Chainlink call API. I made an API and trying to call it from my Chainlink through smart contract. As I linked my API to bridge in Chainlink Operator UI, I try to ...
1 vote
1 answer
73 views

Uniswap v3 TWAP oracle

What's the purpose of secondsAgo, in regards to price accuracy, when using it on observe() to get the tickCumulatives, which you can later use in OracleLibrary.getQuoteAtTick() to get the price of a ...
1 vote
0 answers
28 views

Manipulate Uniswap oracles

Is it practically safe to consume from Uniswap v3 spot TWAP oracles on big pairs like WETH/USDC for example? I mean, I know it's technically possible to manipulate them, but based on this article, it ...
0 votes
1 answer
791 views

Hardhat test, await not resolving in time

I have been trying to add to write my own basic tests for a chainlink oracle response. I am adding these tests to Ampleforth's test folder. However, the tests I am running are for the moment very ...
1 vote
1 answer
29 views

Chainlink client oracle pricing

I'm currently utilizing Chainlink Oracle to make API calls. According to the documentation, each call on testnet costs 0.1 Link. However, I'm curious about where I can locate pricing information for ...
1 vote
1 answer
29 views

Ethereum off chain data

I was wondering if it's currently possible to verify personal or private information on-chain on Ethereum. Specifically, I would like it to be verifiable that a certain amount of an ETF is held on a ...
2 votes
1 answer
212 views

How chainlink guarantees the authenticity and accuracy of the data it returns to the smart contract

Given that the oracle and the "request/response" mechanism may be operated by multiple entities, the possibility of data being tampered with during transmission obviously exists. I want to ...
0 votes
1 answer
700 views

Time Specified calls in Solidity using Oraclize

I have started learning coding in Solidity and I have written the below contract using the official Oraclize guidelines. My aim is to: Make the update() function be called on its own on the ...
2 votes
1 answer
1k views

How to validate the Chainlink price feed at a specific time

Suppose that in my solidity contract, I need to see the price of ETH in terms of USD at a specific time, say on January 1, 2021. I would like to use the Historical Price Data Feed from chainlink (URL ...
6 votes
3 answers
1k views

Is it secure to read USD / ETH rate from exchanges directly without using price oracles?

Is it possible to read USD/ETH rate directly from some known smart contract without an oracle? I have a working solution via an oracle. However, my client says it should be possible to read the ...
1 vote
1 answer
52 views

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

I am new to blockchain currently learning and exploring. I followed Patrick's tutorial and now in order to have hands-on I want to implement a FundMe smart contract but for my national currency ...
0 votes
1 answer
375 views

How to Implement off chain Keepers for Decentralize Perpetual Exchanges like GMX.io?

I'm attempting to clone gmx.io. I understand most of the on-chain and Dex concepts, but I'm stumped on how to establish an off-chain Keepers they did not opensource the code for that, so could you ...
1 vote
3 answers
171 views

ChainLink ETH/USD price oracle manipulation

I will be concise. I am using ChainLink ETH/USD price feed in my smart contracts. I am ready to deploy the smart contracts so I did a little bit of legwork researching mainstream hacks and one ...
0 votes
1 answer
275 views

chainlink oracle http get request not returning value - taken from example but still is not working

I have my own oracle code that suddenly stopped returning any output. So I double checked with the official Chainlink oracle example on remix and that is also not returning any value... I have sent ...
0 votes
1 answer
16 views

How to change response from oracle?

I need to test my contract, and to test I need to change data that I recieve from ChainLink Oracle (I get Ethereum price from it). So how can I change price on ETH local for tests using Ganache-Cli or ...
1 vote
1 answer
566 views

Why does getting random numbers using Chainlink take more than 30 seconds?

I'm writing an article and I'm using Chainlink VRF in one part. Theoretically, this is a two-transaction process, as it is impossible to storethe cryptographic proof on the blockchain and read the ...
0 votes
1 answer
19 views

Oracle For Exchange Defaults

Simple question, is there a trustworthy oracle that can tell me whether an exchange (e.g. binance) defaulted, froze withdrawals, etc.
0 votes
1 answer
25 views

Is it possible Randomly generate and privately store data using Chainlink?

I'm working on a social coordination game for the Chainlink Constellation Hackathon. Game mechanics are similar to Mafia, Bang! or AmongUs where roles are assigned at the onset of the game. Roles ...
1 vote
1 answer
14 views

Oracle node to connect with the NYSE

Does exist an oracle that it’s able to connect with the NYSE or others stock markets? If so, could you please tell me which?
1 vote
2 answers
352 views

How secure is an Oracle?

I am working on oracles. I saw this link - https://kndrck.co/posts/ethereum_oracles_a_simple_guide/ The code works, I tested it. But what is the issue to me, is the code actually secure? Can someone ...
1 vote
2 answers
114 views

Chainlink Any API: ETHABIEncode while parsing ABI string: bad ABI specification: unsupported arg type: Trade: bad input for task

I am trying to fetch data from an api which gives multiple response in single call and I am doing this using chainlink external API calls. In my smart contract i have use array of struct to store ...
0 votes
1 answer
131 views

How to we fetch price of NFT index using chainlink

i was wondering if we can fetch the price of different NFT index using chainlink price oracle, i had done the same earlier to find the pricefeed for ETH to USD , now i want same for NFT collection.
1 vote
0 answers
68 views

What happens with Chainlink price feed when L2 sequencer is down?

What exactly happens with chainlink price feeds when an L2 sequencer is down? I know that during this moment transactions can be submitted only through L1 rollup contract and that some users can be ...
2 votes
0 answers
48 views

Oracles supporting Polygon Zkevm

Are there any oracles present at the moment supporting smart contracts to securely retrieve data from conventional APIs (not data feeds) through HTTP(S) GET and POST calls. We have looked into Witnet, ...
1 vote
1 answer
46 views

is it necessary to use oracles for Integrating IoT Sensors and smart contract in a Supply Chain Management DApp?

What are the best practices and methodologies for developing a decentralized application (dapp) that focuses on streamlining supply chain management processes through the integration of IoT sensors? ...
0 votes
0 answers
18 views

Random delay inside a smart contract function

So, I'm trying to implement an anti-sniping feature that would make the users wait a random time between 0-12 seconds - specifically 0, 3, 6, 9 or 12 seconds because my smart contract would be on BSC. ...
0 votes
1 answer
33 views

Automate Chainlink Get API

I am working on a Parametric Insurance contract, the API call is working as expected, but I need to automate the call to the requestRainData() function. I need to constantly check if the rain MM in a ...
0 votes
1 answer
50 views

Another contract is intercepting my contract calls and stealing the funds, what can it be?

This is the code I have, and I deployed to polygon mainnet to test. https://polygonscan.com/address/0x3CC3F39cc2386a8847378F4022917B3bB623BAFD // SPDX-License-Identifier: MIT // An example of a ...
0 votes
1 answer
24 views

Chainlink vs DEXs & NFT Market prices

I am doing a futures dApp, so I need the price of the underlying assets (all assets are on-chain not fiat). What is the difference between using DEX and NFT Marketplace on-chain prices as oracle and ...
1 vote
1 answer
259 views

How to import file with hardhat

I'm following the Alchemy tutorial to build an NFT Marketplace with hardhat. I want to import my smart contract which is an APIConsumer by Chainlink. I can't do it by path since I'm not allowed by ...
1 vote
1 answer
17 views

Using Chalink oracle for ethereum application

Is using any Offchain data like chainlink oracle is safe as far security is concerned for any ethereum application and how does ethereum ensures that is is safe to use them
0 votes
1 answer
166 views

How is consensus reached in a Decentralized Oracle Network?

I understand the deterministic nature of blockchains thus the need for oracles to feed outputs of non deterministic algorithms or API-calls to smart contracts. Using a single node oracle would defeat ...
4 votes
1 answer
301 views

What is the verification process of nodes on chainLink?

chainLink is a decentralized system similar to Ethereum, which can help smart contracts execute get requests and return the results. The result of chainLink execution also needs to be verified by ...
2 votes
2 answers
95 views

How do I become a reporter for Tellor?

I want to become a reporter for Tellor, but not sure where to begin. Are there any guides or tutorials?
1 vote
1 answer
24 views

Oracle recommendations for stablecoin project

Looking for an oracle to add to my stablecoin project. Want the essentials (decentralized, censorship-resistant, secure mechanics, no multi-sig to control everything). Any ideas?
0 votes
2 answers
112 views

How to get a tweet content using oracle in the smart contract to verify a user

I am trying to verify a user using his social media account. For this purpose, I am creating a registration function where a user needs to post his tweet with his existing EOA address. How can I ...
0 votes
2 answers
469 views

Does running a Geth RPC server locally also require having a full Ethereum node?

I've been trying to learn about smart contracts and attempting to work through a few examples. Specifically, I found this one about creating an Oracle -- https://github.com/axic/tinyoracle. The ...
0 votes
1 answer
45 views

Whitelist and identity tracking of NFT holders

I am working on ERC1155 NFT collection and because of the regulation related to the project I am part of, we are required to allow only certain users to hold the NFT. For that reason, I want to ...
0 votes
3 answers
240 views

buildChainlinkRequest function of Chainlink is not working properly

The buildChainlinkRequest line no 47 takes 3 parameters: JobId Callback Address Function to callback to I have smartcontract1 and smartcontract2. The below mentioned function is inside ...
0 votes
1 answer
73 views

Address to String in Chainlink Request is giving error?

When i am using req.add("publicKey","any_public_key_here_as_string"); I have 2 steps mentioned in our job specification decode_cbor [type=cborparse data="$(decode_log.data)&...

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