Note

This repository represents an example of using a Chainlink product or service. It is provided to help you understand how to interact with Chainlink’s systems so that you can integrate them into your own. This template is provided "AS IS" without warranties of any kind, has not been audited, and may be missing key checks or error handling to make the usage of the product more clear. Take everything in this repository as an example and not something to be copy pasted into a production ready service.

This repository contains the basic implementation of EIP 7412 compatible smart contract using Chainlink Data Streams.

Below is the sequence diagram of triggering and getting the latest price data from Chainlink Data Streams DON.

sequenceDiagram
    participant Client as Off-chain client (index.ts)
    participant Contract as DataStreamsErc7412Compatible.sol
    participant DON as Data Streams DON
    participant Multicall as Multicall3_1.sol
    participant FeeManager as FeeManager.sol
    participant Verifier as Verifier.sol

    Client->>Contract: generate7412CompatibleCall(feedIds)
    activate Contract
    Note over Contract: Reverts with OracleDataRequired error
    Contract-->>Client: revert IERC7412.OracleDataRequired(oracleQueryData)
    deactivate Contract

    activate Client
    Client->>Client: fetchOffchainData(oracleQueryData)
    Client->>DON: fetchFeedsRaw(timestamp, feedIds)
    DON-->>Client: return fullRawReports
    Client->>Client: encodes signedOffchainData
    Client->>Multicall: aggregate3([call])
    deactivate Client

    Multicall->>Contract: fulfillOracleQuery(signedOffchainData)
    activate Contract
    Contract->>Contract: decodes signedOffchainData
    loop for each signed report
      Contract->>FeeManager: getFeeAndReward(reportData, feeTokenAddress)
      Note right of Contract: Handle billing<br />.<br />If not enough LINK or native coins<br />revert with IERC7412.FeeRequired
      Contract->>Verifier: verify(report, feeTokenAddress)
      Verifier-->>Contract: returns verifiedReport
      Note over Contract: Logs price from a report
      Contract->>Contract: emit PriceUpdate(verifiedReport.price, verifiedReport.feedId)
    end
    deactivate Contract

• Node.js version 20 or above
• Foundry installed
• Alchemy API key for Arbitrum Sepolia testnet
• 1 Arbitrum Sepolia LINK and some amount of Arbitrum Sepolia ETH (for gas costs)
• Chainlink Data Streams credentials

1. Install dependencies:

forge install

npm install

2. Compile smart contracts:

forge build

3. Deploy DataStreamsERC7412Compatible smart contract

forge create --rpc-url <ARBITRUM_SEPOLIA_RPC_URL> --private-key <DEPLOYER_PRIVATE_KEY> contracts/DataStreamsERC7412Compatible.sol:DataStreamsERC7412Compatible --constructor-args 0x2ff010DEbC1297f19579B4246cad07bd24F2488A

The 0x2ff010DEbC1297f19579B4246cad07bd24F2488A is the address of a Verifier smart contract, to get more details visit Stream IDs page at the official Chainlink Documentation.

4. Deploy Multicall3_1 smart contract

forge create --rpc-url <ARBITRUM_SEPOLIA_RPC_URL> --private-key <DEPLOYER_PRIVATE_KEY> contracts/Multicall3_1.sol:Multicall3_1

5. Set the following environment variables

WALLET_PRIVATE_KEY=
CHAINLINK_CLIENT_ID=
CHAINLINK_CLIENT_SECRET=
CHAINLINK_API_URL=
CHAINLINK_WEBSOCKET_URL=
ALCHEMY_KEY=
DATA_STREAMS_ERC7412_COMPATIBLE_CONTRACT_ADDRESS=
MULTICALL3_1_ADDRESS=

6. Fund the DataStreamsErc7412Compatible smart contract by transferring at least 1 Arbitrum Sepolia LINK to the DATA_STREAMS_ERC7412_COMPATIBLE_CONTRACT_ADDRESS, for example from Metamask wallet.

7. Run end-to-end demonstration on Arbitrum Sepolia

npm start

You will see the URL to the Arbitrum Sepolia block explorer with a transaction hash in the Terminal, for example:

> start
> npm run compile && node dist/index.js


> compile
> tsc

Transaction hash: https://sepolia.arbiscan.io/tx/0xa6092c573aac7b48330e6a7df824a5fda5193e37b7652b11b18d73b98debf7b1

If you repeat the command, and the latest price hasn't expired yet, you will see the log with the latest cached price from the DataStreamsERC7412Compatible smart contract, for example:

> start
> npm run compile && node dist/index.js


> compile
> tsc

Latest price of 0x00027bbaff688c906a3e20a34fe951715d1018d262a5b66e38eda027a674cd1b feed ID: 2419103125435294300000

You will see logs with actual prices if you check the Events tab of the DataStreamsErc7412Compatible smart contract at block explorer at https://sepolia.arbiscan.io/address/DATA_STREAMS_ERC7412_COMPATIBLE_CONTRACT_ADDRESS#events, for example