General approach
When it comes to contract code, the main contract will seem small. All the real math happens in the libraries - there are five of them. The approach was to build things in such a way that further modification of the contract doesn’t break the one really important thing: testing. So each library has its own test unit.
I hope this makes contributing easier for you too - you can rework a single unit without needing to explore the whole project. If you read it and think it is nice to try it out, check out Contribute !
Main code (src/)
src/MPFHook.sol - the Uniswap v4 hook itself. Holds all contract storage; contains no math of its own, only orchestration that feeds data into the libraries below.
src/lib/FrugalMedianLibrary.sol - pure math for a frugal-streaming approximate median estimator, letting the hook track a running median of priority fees without storing full history.
src/lib/PenaltyFeeLibrary.sol - pure math for the penalty curve plus its constants; given a swap’s priority fee and the reference median, returns the LP fee to charge.
src/lib/GetPriorityFeeLibrary.sol - reads the current transaction’s priority fee from tx.gasprice / block.basefee, floored at zero for legacy transactions.
src/lib/SnapshotWindowLibrary.sol - maintains a rolling per-block window of median snapshots and averages it, smoothing out single-block manipulation attempts before the fee decision is made.
src/lib/TickCheckerLibrary.sol - gates whether a swap is allowed to update the running median, requiring the pool’s tick to have moved enough (scaled by liquidity) since the last accepted update.
Tests (test/)
test/unit/PenaltyFeeLibrary.t.sol - checks the penalty curve’s shape: no fee below threshold, monotonic increase, and saturation at the max.
test/unit/FrugalMedianLibrary.t.sol - isolates the median estimator’s convergence and step-size behavior over a sequence of observations.
test/unit/GetPriorityFeeLibrary.t.sol - isolates priority-fee reading under different vm.fee / vm.txGasPrice combinations, including the legacy-transaction edge case.
test/unit/SnapshotWindowLibrary.t.sol - isolates the snapshot window’s once-per-block recording, circular-buffer wraparound, and averaging.
test/unit/TickCheckerLibrary.t.sol - isolates the tick-movement gate, from baseline establishment through acceptance/rejection at different liquidity levels.
test/integration/MPFHook.t.sol - deploys the hook against a local PoolManager and drives it through real swaps, exercising all five libraries together via the hook’s orchestration layer.
test/fork/MPFHookForkIntegration.t.sol - end-to-end test on a forked mainnet RPC against the real WETH/USDC pool, validating the assembled system under real liquidity conditions.
test/utils/BaseTest.sol, Deployers.sol, libraries/EasyPosm.sol - shared test infrastructure (pool/currency deployment helpers, liquidity-position minting) used by the integration tests.
Last modified on August 20, 2026
