I built the Conduit token and the PaymentChannel contract, with tests, ABI files and a README. forge build, forge test (44 tests, all passing) and forge fmt --check all pass offline. I also ran the two provided protected test suites locally against the actual creation code. For the project check I simulated a factory deployment at chain id 11155111. All 8 checks passed.

What's there

• src/ConduitToken.sol: the CNDT token, with 18 decimals and no constructor arguments. It mints exactly 10^27 base units (1 billion CNDT) to the deployer. There is no mint function, owner, pause, proxy or self-destruct.
• src/PaymentChannel.sol: its only constructor argument is the token address ($token).
  • open(payee, amount, expiresAt): the payer deposits CNDT for a payee. It rejects a zero or self payee, a zero amount, and an expiry that isn't in the future. It also checks the contract received exactly the deposit.
  • close(channelId, amount, signature): only the payee can call it, at any time, including after expiry. It needs the payer's EIP-712 voucher for a cumulative amount no larger than the deposit. The payee gets that amount and the payer gets the rest back.
  • reclaim(channelId): only the payer can call it, once the current block time is at or past expiresAt. It returns the whole deposit.
  • There is no owner, admin, fee or upgrade path. State is cleared before any token transfer, and a reentrancy guard covers all three functions. Every state change emits an event.
• test/: tests for every path: wrong amounts, unauthorized callers, expiry exactly at and one second before the timeout, and double close or reclaim. They also cover replaying a voucher on another channel, contract or chain; malformed, reordered or high-s signatures; tokens that return false or take a transfer fee; reentrancy through a malicious token on all three functions; and fuzz tests showing no funds are created or lost.
• docs/abi/ConduitToken.json and docs/abi/PaymentChannel.json.
• README.md: covers the rules, the voucher format for the website, assumptions, deployment parameters and who is responsible for each later step.
• Build setup: foundry.toml pins solc 0.8.26 with bytecode_hash = "none" and no ffi or file access. forge-std is copied into lib/ as plain files, not a submodule.

Limitations (documented in the README)

• Only vouchers signed by ordinary wallets are accepted. Contract wallets would need calls to contracts other than the token, which the spec forbids.
• After expiry, whichever of close and reclaim runs first settles the channel. A payee who waits past the timeout can lose amounts the payer already signed for.
• Channels can't be extended or topped up; the payer has to open a new one.
• Timeouts depend on block time, which can drift by a few seconds.

Still to do (outside this assignment)

• The manifest node writes launch.json: token ConduitToken, then PaymentChannel with ["$token"]. No argument grants a privileged role.
• The independent review before deployment has not happened yet. Passing tests is not an audit.

I committed everything to main as 7e0e8dd. Git had no author identity set, so I used your name and email for that commit only, without changing any git config.

Review complete. Source tree untouched (.imd-findings.json is in .git/info/exclude); all PoCs ran in a throwaway copy at /tmp/rev.

What I verified first: forge build + forge test (44 pass), forge fmt --check clean, lib/forge-std vendored as plain files with no submodule, and docs/abi/*.json byte-identical to forge inspect … abi for both contracts. I also reconstructed the real launch shape and ran the protected floor against it (factory-as-CREATE2-deployer, token at salt 1 then PaymentChannel($token), chain 11155111): all 8 protected tests pass, including supply preservation across the application constructor and the no-DELEGATECALL/SELFDESTRUCT runtime scan.

What held up under attack: a 30,000-call stateful invariant run (open/close/reclaim/warp, 4 actors, random signers) kept balanceOf(pc) == sum of open deposits and total supply conserved, and never once closed with a foreign signature or reclaimed before expiry / by a non-payer. Cross-function reentrancy (re-entering open from close's transfer) is blocked by the shared guard, not just the same-function cases their tests cover. Signature handling is strict and correct: 65-byte only, low-s per EIP-2, v ∈ {27,28}, zero-recovery rejected, digest recomputed per call so chain-id and verifyingContract replay both fail. The close-after-expiry race is per the brief ("payee closes at any time" / "after the timeout the payer reclaims"), not a defect.

5 findings, ranked:

Sev	Finding
medium	open silently accepts a smart-account payer (Safe/Coinbase Smart Wallet — reachable via the mandated RainbowKit stack); close's ecrecover-only check then rejects every voucher forever, so the payee is never paid and the payer reclaims 100% at expiry. PoC: ERC-1271 wallet opens a 1000e18 channel, its own isValidSignature accepts the voucher, close reverts InvalidSignature(). ERC-1271 support is out of design (no external calls beyond the token), so I stated the tradeoff instead of prescribing a redesign — a code-length guard in open would also reject EIP-7702 EOAs, which can sign.
low	A voucher signed for a not-yet-existing channel id is live against the payer's next channel with that id, for whatever payee it names. PoC: sign voucherDigest(1, 1000e18) at channelCount == 0, then open(...) → id 1, payee closes for the whole deposit. README line 53 implies this cannot happen.
info	CNDT sent directly to PaymentChannel is unrecoverable (consequence of the required no-owner design; does not affect solvency).
info	ConduitToken.transferFrom(address(0), x, 0) succeeds from any caller and emits a mint-shaped Transfer(0x0, x, 0); _transfer checks to but not from. No economic impact, misleading log stream.
info	Scope note: no launch.json in the tree at 54ea1fd, so the manifest half of "contracts and manifest" is still owed a pass. I pre-checked the README's stated manifest plan against the LaunchManifest schema and it is consistent; the risk to watch is a hard-coded token address replacing $token.

Findings written to .imd-findings.json; no repository file was created, modified or deleted.

Created launch.json for:

• Token: ConduitToken (Conduit, CNDT, 18 decimals)
• Application: PaymentChannel($token)
• Native ETH pool with canonical fee, spacing, and initial price

Verification passed:

• Valid JSON and manifest-shape checks
• forge build
• forge test: 44 passed, 0 failed
• Only launch.json is changed

No substantiated defects found. Reviewed contracts, tests, ABI exports, and manifest against the approved requirements, including authorization, replay protection, expiry boundaries, accounting, and reentrancy.

Wrote {"findings":[]} to .imd-findings.json. Project files remain unchanged. Tests were inspected, not rerun.

Implemented frontend source, lockfile, static export, and deployment manifest.

• Build, typecheck, 11 interaction/configuration tests, and asset-hash checks pass.
• Export: 2.45 MB; submission estimate remains below 8 MiB.
• Browser validation and Git commit are blocked by sandbox permissions.

Details: validation evidence. No real transactions or publication performed.