Hardhat Kaia Oracles starter kit
npm install @kaiachain/kss-oraclesOracles take data from the outside world and put it into the blockchain for other smart contracts to consume.
This is a hardhat project containing contracts and scripts for Witnet integrations.
``typescript`
npm install -g @kaiachain/kss-cli --force
`typescript
> kss-cli oracle init
> cd oracle-starter-kit
> npm install --force
`
Above commands downloads the oracle-starter-kit folder structure in the current project directory.
Enter inside the generated folder and install the packages as mentioned
From there you can run hardhat commands to compile your contracts, deploy those contracts to
the network and run their associated unit tests.
Default configurations of kairos network .$3
Hardhat configuration variables can be found in helper-hardhat-config.json in the root directory. Below is the configuration explaination for 1001 network. *
name - hardhat network name Ex: kairos
* - witnetPriceRouter Address Ex: 0xeD074DA2A76FD2Ca90C1508930b4FB4420e413B0 for Kaia Kairos Testnet. See WitnetPriceRouter for reference.
* witnetRandomness - witnetRandomness Address. Ex: 0xb4b2e2e00e9d6e5490d55623e4f403ec84c6d33f for Kaia Kairos Testnet. See WitnetRandomness Contract Addresses for reference.
$3
We will need to set environment variables by following below steps
1. copy .env.example file and rename to .env
2. Modify environment variables. Below is the explaination of each variable
* - string https://public-en.kairos.node.kaia.io can be used. its the rpc url of blockchain.
* PRIVATE_KEY - string This is private key from wallet, ie MetaMask. This is required for deploying contracts to public networks. > IMPORTANT: MAKE SURE YOU DON'T EXPOSE THE KEYS YOU PUT IN THIS
.env FILE saved in the package node_modules. By that, I mean don't push them to a public repo, and please try to keep them keys you use in development not associated with any real funds. Don't commit and push any changes to .env files that may contain sensitive information, such as a private key! If this information reaches a public GitHub repository, someone can use it to check if you have any Mainnet funds in that wallet address, and steal them!
> Get some Baobab Testnet KLAY
Go to the Kaia faucets to get some KLAY to configured private key account.
Deploy contracts
You should now be all setup! You can run any method now! Since we configured the environment variables and hardhat configurations so you don't really need to pass any configurations.
To comple contracts
`
npx hardhat compile
To deploy all contracts
npx hardhat deploy --network baobab
To run tests
npm run test
Interacting with Deployed Contracts
After deploying your contracts, the deployment output will give you the contract addresses as they are deployed.You can then use these contract addresses in conjunction with Hardhat tasks to perform operations on each contract.
$3
The Witnet Price Feeds consumer contract has one task, to read the latest price of a specified price feed contractbash
npx hardhat read-witnet-price-feed --contract --id --network baobab
`#### Parameters
- string Deployed WitnetPriceFeed contract address
id - string id is the witnet pricefeed ID. Ex: 0x6cc828d1 for Price-KLAY/USD-6. See Kaia Witnet PriceFeeds for reference.#### Returns
*
price - price of KLAY/USD. #### Example
`typescript
// 1 KLAY = 0.23 USD
npx hardhat read-witnet-price-feed --contract 0x573AAAdF4Cf117586e74AE3845473fc65cd59C4c --id 0x6cc828d1 --network baobab /*
Last price is: 237467
Last timestamp is: 1678713345
*/
`$3
The Witnet Randomness has 4 tasks.
Make sure the deployWitnetRandomNumber method successful execution.> This 2-step process preserves unpredictability of the random numbers that you get because it guarantees that the number is derived from a seed that was generated only after the request was sent.
> _NOTE:_ Initially 1 and 2nd step has to be completed sequentially. Only after that 3rd or 4th can be executed for fetching a random number.
#### 1. Request new randomness
Requesting the new randomness.
Once the the request to new randomness is performed successfully. The other tasks can be performed after transaction submission.
bash
npx hardhat request-witnet-randomness --contract --value --network baobab
`#### Parameters
- string Deployed Deployed Witnet RandomNumber contract address
value - number Value for transaction cost when requesting random numbers. Ex: 500000000000000000 i.e, 0.5 KLAY##### Returns
*
transaction hash - Transaction hash##### Example
`typescript
npx hardhat request-witnet-randomness --contract 0x8937C127F3060fF8a23E9a0fb5AEA10bc30e28be --value 500000000000000000 --network baobab
/*
Transaction Hash: 0x809addb235dc953c90a563c396c11978a359b574336564c7ec890514c961e050
*/
`#### 2. Fetch Witnet random number
Initiate fetch witnet random number transaction.
> WARNING:
Calling
right after request-witnet-randomness will most likely cause the transaction to revert. Please allow 5-10 minutes for the randomization request to complete`bash
npx hardhat fetch-witnet-random-number --contract --network baobab
`#### Parameters
- string Deployed Witnet RandomNumber contract address##### Returns
*
transaction hash - Transaction hash##### Example
`typescript
npx hardhat fetch-witnet-random-number --contract 0x8937C127F3060fF8a23E9a0fb5AEA10bc30e28be --network baobab
/*
Transaction Hash: 0x0eb8fe1217ecdc3860009bc49f5319cab6ffdedd80877c39df02899a3542db24'
*/
`#### 3. Get the latest randomizing block
bash
npx hardhat read-latest-randomizing-block --contract --network baobab
`#### Parameters
- string Deployed Witnet RandomNumber contract address##### Returns
*
randomizingBlock - randomized block value##### Example
`typescript
npx hardhat read-latest-randomizing-block --contract 0x8937C127F3060fF8a23E9a0fb5AEA10bc30e28be --network baobab
/*
The latest randomizing block is: 113690138
*/
`#### 4. Get the generated random number
fetches the generated random number
> _NOTE:_ Make sure first 2 steps are executed sequentially.
bash
npx hardhat read-witnet-random-number --contract --network baobab
`#### Parameters
- string Deployed Witnet RandomNumber contract address##### Returns
*
randomNumber - generated random number##### Example
`typescript
npx hardhat read-witnet-random-number --contract 0x8937C127F3060fF8a23E9a0fb5AEA10bc30e28be --network baobab
/*
Random Number is: 1392104028
*/
`$3
We have 2 examples for Witnet HTTP Request:
- KlayPrice: a GET request example to get Klay token price in USD
- postRequestExample: a POST request example echoes back any data and headers that you send in your POST requests (based on this tutorial)Inside
folder you will find predefined Witnet oracle queries.You can follow this link to learn how to create other queries.
#### Compile the Witnet queries into Solidity contracts
`
npx rad2sol --target ./witnet-queries --write-contracts ./contracts/witnet-requests
##### Example
npx rad2sol --target ./witnet-queries --write-contracts ./contracts/witnet-requests
#### Execute Witnet Queries
After the contracts have been created, you can query locally to preview the result by running:
npx witnet-toolkit try-query --from-solidity ./contracts/witnet-requests/
##### Parameters
- string generatedSolFileName##### Returns
*
Result - string##### Example 1 - Fetch Coinprice
typescript
// 1 KLAY = 0.19 USD. Divide the return value by 10^6 to get actual coin price result.
npx witnet-toolkit try-query --from-solidity ./contracts/witnet-requests/coinPrice.sol
/*
Result: 195467
*/
`##### Example 2 - Post Request
typescript
// Gets parsed data of headers.Header-Name from the post api
npx witnet-toolkit try-query --from-solidity ./contracts/witnet-requests/postAPI.sol
/*
Result: "Header-Value"
*/
`> _NOTE:_ If above tryWitnetQueries is stuck, please try to run command shown in below snapshot
, install the binary once in the machine and retry above method
!WitnetToolkitBinary$3
The Supra Price Feeds consumer contract has one task, to read the latest price of a specified price feed contract`bash
npx hardhat read-supra-price-feed --contract --network baobab
`
#### Parameters
- string Deployed SupraValueFeedExample contract address
marketpair - string marketpair is the Supra marketpair id. Ex: btc_usdt. See Kaia Supra PriceFeeds for reference.
#### Returns
*
price - price of BTC/USD. #### Example
`typescript
// 1 BTC = 28837.54156500 USD
npx hardhat read-supra-price-feed --contract 0x80d2d67802942e9060122fafdf62bdc747d09021 --marketpair btc_usdt --network baobab
``- Witnet Documentation
- Hardhat Documentation