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IFdcHub

Primary interface for interacting with the Flare Data Connector (FDC).

Sourced from IFdcHub.sol on GitHub.

Overview​

The IFdcHub interface serves as the main entry point for applications requesting attestations from the Flare Data Connector. It provides functionality to request attestations, access configuration contracts, and handle related events.

Functions​

fdcInflationConfigurations​

Returns the FDC inflation configurations contract address.

function fdcInflationConfigurations(
) external view returns (
    contract IFdcInflationConfigurations
);

Returns

  • IFdcInflationConfigurations: Contract interface for accessing inflation configurations

fdcRequestFeeConfigurations​

Returns the FDC request fee configurations contract address.

function fdcRequestFeeConfigurations(
) external view returns (
    contract IFdcRequestFeeConfigurations
);

Returns

  • IFdcRequestFeeConfigurations: Contract interface for accessing request fee configurations

requestAttestation​

Requests an attestation from the Flare Data Connector.

function requestAttestation(
    bytes _data
) external payable;

Parameters

  • _data: ABI encoded attestation request

Note: This function is payable and requires a fee based on the attestation type.

requestsOffsetSeconds​

Returns the offset (in seconds) for the requests to be processed during the current voting round.

function requestsOffsetSeconds(
) external view returns (
    uint8
);

Returns

  • uint8: Offset in seconds

Events​

AttestationRequest​

Emitted when an attestation request is submitted.

event AttestationRequest(
    bytes data,
    uint256 fee
)

Parameters

  • data: The encoded attestation request data
  • fee: The amount paid for the attestation request

InflationRewardsOffered​

Emitted when inflation rewards are offered.

event InflationRewardsOffered(
    uint24 rewardEpochId,
    struct IFdcInflationConfigurations.FdcConfiguration[] fdcConfigurations,
    uint256 amount
)

Parameters

  • rewardEpochId: The ID of the reward epoch
  • fdcConfigurations: Array of FDC configurations
  • amount: The total amount of rewards offered

RequestsOffsetSet​

Emitted when the requests offset is updated.

event RequestsOffsetSet(
    uint8 requestsOffsetSeconds
)

Parameters

  • requestsOffsetSeconds: The new offset value in seconds

Usage Example​

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@flare-foundation/flare-smart-contracts-v2/contracts/userInterfaces/IFdcHub.sol";
import "@flare-foundation/flare-smart-contracts-v2/contracts/userInterfaces/fdc/IAddressValidity.sol";

contract AddressValidator {
    IFdcHub private fdcHub;

    constructor(address _fdcHubAddress) {
        fdcHub = IFdcHub(_fdcHubAddress);
    }

    function validateAddress(string memory addressStr, bytes32 sourceId) external payable {
        // Create address validity request
        IAddressValidity.RequestBody memory requestBody = IAddressValidity.RequestBody({
            addressStr: addressStr
        });

        // Encode the full request
        bytes memory encodedRequest = abi.encode(
            bytes32(0x05), // attestationType for AddressValidity
            sourceId,
            bytes32(0), // messageIntegrityCode - should be calculated properly
            requestBody
        );

        // Submit the request with appropriate fee
        fdcHub.requestAttestation{value: msg.value}(encodedRequest);
    }
}