Epix Tipping

Tipping smart contract for Epix Chain. Users tip content creators with native EPIX, with on-chain stats for UI rendering. Demonstrates how to integrate the xID precompile into Solidity contracts.

xID Integration

Epix Chain provides an xID precompile at 0x0000000000000000000000000000000000000900 that lets smart contracts resolve human-readable names to EVM addresses (and vice versa) without any external oracle or off-chain lookup.

Interface

Copy src/IXID.sol into your project to use the xID precompile:

address constant XID_PRECOMPILE_ADDRESS = 0x0000000000000000000000000000000000000900;
IXID constant XID = IXID(XID_PRECOMPILE_ADDRESS);

interface IXID {
    // "mud" + "epix" -> 0x1234...
    function resolve(string calldata name, string calldata tld) external view returns (address owner);

    // 0x1234... -> ("mud", "epix")
    function reverseResolve(address addr) external view returns (string memory name, string memory tld);

    // Same as reverseResolve but returns the user's chosen primary name
    function getPrimaryName(address owner) external view returns (string memory name, string memory tld);
}

Forward Resolution (name to address)

Resolve an xID name to an EVM address. This contract uses it to let users tip by name instead of address:

function tipByXid(bytes32 contentHash, string calldata name, string calldata tld) external payable {
    address resolved = _tryResolve(name, tld);
    require(resolved != address(0), "xID: name not found");
    _tip(contentHash, resolved);
}

function _tryResolve(string calldata name, string calldata tld) private view returns (address) {
    try XID.resolve(name, tld) returns (address owner) {
        return owner;
    } catch {
        return address(0);  // precompile unavailable or name not found
    }
}

Reverse Resolution (address to name)

Look up the xID name for an address. This contract uses it to display tipper names in leaderboards:

function _tryReverseResolve(address addr) private view returns (string memory name, string memory tld) {
    try XID.reverseResolve(addr) returns (string memory n, string memory t) {
        return (n, t);
    } catch {
        return ("", "");  // no xID registered
    }
}

Best Practice: Always Wrap in try/catch

The xID precompile is a chain-level feature. If your contract might be deployed on a fork, testnet, or chain where the precompile isn't available, wrap calls in try/catch to prevent reverts from bricking your contract.

How It Works

Each piece of content (forum post, blog entry, social post) is identified by a bytes32 content hash:

contentHash = keccak256(abi.encode(siteAddress, authorDirectory, postId))

The first tip to a content hash permanently registers the creator address. Subsequent tips are forwarded directly to the creator. 100% of every tip goes to the creator - no fees, no admin, no pause.

Stats Tracking

The contract tracks stats on-chain for UI rendering (all free to read via eth_call):

• Summary - creator address, total EPIX tipped, unique tipper count (2 storage slots)
• Top 3 - highest cumulative tippers with amounts and xID names
• Last 3 - most recent tips with timestamps and xID names

Usage

// Tip by direct address
tipping.tip{value: 1 ether}(contentHash, creatorAddress);

// Tip by xID name (resolves on-chain)
tipping.tipByXid{value: 1 ether}(contentHash, "mud", "epix");

// After creator is registered, address(0) uses stored creator
tipping.tip{value: 1 ether}(contentHash, address(0));

// Quick summary for tip button badge (2 slot reads)
(address creator, uint256 totalAmount, uint32 uniqueTippers) =
    tipping.getContentSummary(contentHash);

// Full stats for tip modal
IEpixTipping.ContentInfo memory info = tipping.getContentInfo(contentHash);

// Batch tip counts for page load (1 RPC call instead of N)
uint32[] memory counts = tipping.getTipperCountBatch(contentHashes);

Development

forge build       # Compile
forge test -vvv   # Run tests
forge fmt         # Format

Deploy

cp .env.example .env
# Edit .env with your deployer key and RPC URL
forge script script/Deploy.s.sol --rpc-url $RPC_URL --broadcast --legacy

Contract Addresses

Network	Address
Testnet	0x22c5622378fb8E9AB52EA0b00cAce94474829df3
Mainnet	TBD

License

MIT