Chainlink Functions Beacon (CLF)

Primary vs. Secondary Functions Consumer

Primary Functions Consumer:

• Directly interacts with Chainlink's decentralized oracle network (DON)
• Must manage its own subscription
• Handle callbacks from oracles themselves
• Consumer pays for compute from subscription-level LINK balance

Secondary Functions Consumer:

• Interact through an intermediary contract (the Chainlink Functions Beacon)
• Pay on a per-transaction basis using native token not LINK subscription
• Receives callbacks through the intermediary client (the primary consumer)

Getting Started with Chainlink Functions Beacon Client

Learn how to integrate with the Chainlink Functions Beacon for off-chain computations and API calls. This guide walks you through creating a client contract (secondary) that interacts with the Chainlink Functions Beacon contract (primary). See Chainlink Functions official documentation.

Prerequisites

• Ethereum development environment (Hardhat/Foundry)
• Web3 wallet with testnet tokens
• Basic Solidity knowledge

Integration Steps (Hardhat)

1. Install Dependencies

npm install @openzeppelin/contracts @chainlink/contracts

2. Create Your Client Contract

• Inherit from Ownable
• Import the beacon interface:

interface IChainlinkFunctionsBeacon {
    function requestComputation(bytes32 data, bytes32 source) external returns (bytes32);
}

3. Implement Required Functions

• Constructor to set beacon address
• requestBeaconComputation() to make requests
• oracleCallback() to receive responses
• Event handlers for tracking request status

4. Handle Responses
   Your contract must implement the callback function:

function oracleCallback(
    bytes32 requestId,
    bytes memory response,
    bytes memory err
) external onlyBeacon

Usage Example

contract SimpleBeaconClient {
    function makeRequest() external {
        bytes32 requestId = beacon.requestComputation(
            data,    // Your encoded request data
            source   // Provider source hash
        );
    }
}

Security Considerations

• Use onlyBeacon modifier for callbacks