Implemented sender and total swap counters, per-swap events, and view getters without changing amounts or fees. Added the launch token, vendored dependencies, and deployment tooling.

Locally verified with Solidity 0.8.26:

• forge build, forge test, and forge fmt --check pass.
• 29 project tests and all 9 supplied checks pass.
• Offline, empty-environment parallel tests pass.

Assumptions and deployment responsibilities are documented in README.md.

Created launch.json with matching contracts and permissions, native ETH pairing, and explicit pool assumptions. The manager assumption uses Uniswap’s documented Ethereum deployment.

Schema validation and forge build passed. All 38 tests passed, including protected checks. Notes: 1,985/4,000 characters. Only launch.json is submitted.

Saved .imd-findings.json.

No substantiated defects. Covered all 13 entry points under Execution Trace, Periphery, and First Principles. All 29 offline Foundry tests passed.

Source files unchanged. Live-chain and protected harness execution were not performed.

Review complete. No defects found in the math, boundary, or numerical-gap area. The findings file is written with an empty list and 17 coverage rows, and the working tree is otherwise untouched.

What I checked. The hook's only arithmetic is two checked uint256 pre-increments in _afterSwap, with the per-sender count written before the total. There is no division, cast, scaling, fee math, or hookData decoding anywhere, so most items in the Math Precision guide have nothing to attach to. I walked the ones that could apply:

• Overflow and rollback. Either counter at its maximum reverts the whole callback, which the existing tests prove by writing storage to the maximum. The two counters cannot drift apart because no path updates one without the other.
• Return-delta boundary. The callback returns a 64-byte encoding of the selector and a zero int128. The core library ignores that delta because the return-delta flag is off, so the hook cannot alter amounts even by accident.
• Edge swap inputs through the real PoolManager. A 1 wei exact-input, a 1 wei exact-output, and a 1e29 partial fill that runs to the price limit each counted exactly once and left the hook holding nothing. A zero amount and an already-crossed price limit both revert inside the PoolManager before the hook runs, so nothing is counted.
• Flag masks. Every constant in HookFlags aliases the core library's constants, the combined flag value is 0x2040, and the match helper masks high bits the same way the upstream miner does, confirmed by fuzzing arbitrary high bits.
• Gas. A first-time sender costs about 84k gas in the callback, under the 100k ceiling the security guide sets. The README already discloses the two fresh storage slots.
• Token. Unmodified OpenZeppelin 5.2 ERC-20 with a one-time mint of 10^27 that uses checked addition. The large-literal line Aderyn flagged is that mint and is correct.

Coverage. All 13 ABI entry points have a row marked holds, plus rows for the two invariants, the flag library, and the constructor. Nothing was left unreached.

Not a finding, worth knowing. The constructor rejects a manager address with no code. The protected floor test handles this by etching a PoolManager at the address baked into the creation code, so the verifier must supply that address through its environment or the hook will not deploy in that harness. That is intended behavior the project tests for, not a defect.

Wrote .imd-findings.json with no substantiated defects and coverage for all 13 entry points.

All 29 Foundry tests passed offline. Production deployment configuration remains unverified because it was not supplied. No production files changed.

The review is complete and written to .imd-findings.json. No source files were changed. The only files I wrote are the findings file and two scratch tests under test/scratch/, which is ignored by git.

Outcome. The swap-counter hook is economically inert and its invariants hold. I found one low-severity defect and recorded one informational observation. There is nothing at medium or above.

Finding 1, low, with proof. The hook's beforeInitialize callback accepts any pool key, including the dynamic-fee sentinel. The pool manager sets such a pool's LP fee to zero and only the hook address may ever raise it. This hook has no code path that does, so the pool trades at zero fee forever and LPs earn nothing. Any third party can open such a pool with the launch token, since initialization is permissionless. The launch manifest schema forbids the dynamic flag for the launch pool itself, which keeps this at low. The attached Foundry proof fails on the current code and passes once the callback rejects dynamic-fee keys, which I verified by applying and then reverting a one-line fix.

Finding 2, info. Counts can be inflated with no tokens and no liquidity. A pool on two codeless addresses accepts a one-wei swap that moves nothing and still reaches afterSwap. The README already states the counts are not Sybil-resistant, so this is a documented trust assumption rather than a defect. I recorded the measured cost so downstream consumers have the numbers.

Coverage. All thirteen listed entry points have a row. Twelve hold, beforeInitialize carries finding 1, and three extra rows record the invariants I checked: total equals the sum of per-sender counts, the hook never alters amounts or fees or holds tokens, and the hook cannot grief swaps. Within my three guides I covered dependency failure, token misbehavior, fee-to-zero, griefing, conservation and view/write coupling, overflow rollback, and the execution-versus-pool-manager seams. I did not run gas profiling on a target chain or fork rehearsal, which the project's own SECURITY.md also lists as outstanding. The existing 29-test suite still passes on the unchanged source.

Added three suites under test/ covering failure paths, counter boundaries, events, views, unchanged swap amounts and fees, and randomized balance/allowance invariants.

forge build and offline forge test pass: 40 passed, 0 failed, 0 skipped. New invariant suites exercised 32,768 calls.

No implementation defects found in these checks. Only test/ was changed.

Wrote .imd-findings.json with no substantiated defects and all 13 entry points covered.

All 40 repository tests passed. Both economics leads reproduced, but neither violates the specified behavior. Production files remain unchanged.