UniswapX Order Indexer

This app indexes UniswapX order executions across multiple chains. UniswapX is Uniswap's intent-based trading protocol where users submit orders that are filled by third-party fillers, providing better prices and MEV protection.

Indexing Methodology

We use a Main.sol file that implements the following architecture:

Triggers

Our listener triggers on UniswapX Reactor contract pre-execution functions:

• preExecuteFunction - Single order execution
• preExecuteBatchFunction - Batch order execution
• preExecuteBatchWithCallback - Batch execution with callback
• preExecuteWithCallback - Single order execution with callback

Order Resolution

We leverage the fact that our indexer acts just like a deployed contract allowing other contracts to interact with it. We inherit from the OrderQuoter contract that exposes the reactorCallback and quote functions which let us:

• Call the reactor's executeWithCallback function in order to simulate execution of order fills. These will result in a call to our listener's reactorCallback with the resolved order.
• We then revert as we don't want the execution to further proceed and fill the order. We put the resolved order in the reversion reason.
• Our quote function catches the reversion and parses the ResolvedOrder from the reversion reason.

This methodology allows us to robustly resolve orders from all types of reactors so long as they implement the IReactor.sol interface without having to import complex decoding logic.

Fee Injection

Reactors may have a ProcotolFeeController contract setup. If we detect one, we use the FeeInjector.sol library in order to inject the fees into the ResolvedOrder struct we've achieved in the previous steps. This library is an almost identical copy of the ProtocolFees.sol contract with small changes.

Event Structure

This is the final event emitted for each indexed order:

{
    "name": "Swap",
    "fields":
    {
        "blockNumber": 32309115,
        "blockTimestamp": 1751407577,
        "chainId": 8453,
        "maker": "472470dc29527b56bbfcd8be7cc930898643f6f5",
        "makerAmt": "403078980",
        "makerToken": "833589fcd6edb6e08f4c7c32d4f71b54bda02913",
        "makerTokenDecimals": 6,
        "makerTokenName": "USDC",
        "makerTokenSymbol": "USD Coin",
        "reactor": "000000001ec5656dcdb24d90dfa42742738de729",
        "taker": "f85e95bef8f2de7782b0936ca3480c41a4b6c59b",
        "takerAmt": "10000000000000",
        "takerToken": "768be13e1680b5ebe0024c42c896e3db59ec0149",
        "takerTokenDecimals": 9,
        "takerTokenName": "SKI",
        "takerTokenSymbol": "SKI MASK DOG",
        "txnHash": "2d7e55e0a27eda4d2cda635d239d94f897567f7ff2274889968362002e9cf420",
        "txnOriginator": "133335936a326d0264d64444278b0ca0d75afca5"
    },
    "metadata":
    {
        "blockNumber": 32309115,
        "chainId": 8453
    }
}