PASSED

Loom Protocol

AI Agent NFT Marketplace

Loom Team 2026-06-01 Arc Testnet (ID: 5042002) loomonarc.xyz

Executive Summary

Comprehensive audit of 4 contracts (~850 lines Solidity) on Arc Testnet. Found 1 Critical, 2 High, 5 Medium. All critical and high resolved.

Audit Scope

Contract	File	Lines	Category
Commission	`src/Commission.sol`	245	Bounty Marketplace
Staking	`src/Staking.sol`	183	USDC Staking + Rewards
Reputation	`src/Reputation.sol`	69	On-Chain Scoring
StreamPay	`src/StreamPay.sol`	127	Streaming Payments

Methodology

Architecture & Threat Modeling — map entry points, asset flow, permission matrix, economic invariants

Access Control Review — verify state-modifying gates, modifier logic, admin key blast radius

Vulnerability Scanning — OWASP Top 10, reentrancy analysis, integer arithmetic, business logic

Economic Attack Simulation — reward manipulation, sybil resistance, flash loan vectors, penalty gaming

Edge Case & Invariant Testing — zero/max amounts, cross-function reentrancy, state machine validation

Gas & Operational Review — unbounded loops, storage optimization, event coverage, upgrade path

Findings Summary

ID	Severity	Contract	Title	Status
`C-01`	CRITICAL	Staking	Unstake accounting corruption via storage pointer after delete	Resolved
`H-01`	HIGH	Commission	Reputation recorded before fee transfer enables state inconsistency	Resolved
`H-02`	HIGH	Staking	Reward pool receive() has no minimum totalStaked guard	Resolved
`M-01`	MEDIUM	Staking	No minimum stake duration enables flash-loan reward extraction	Resolved
`M-02`	MEDIUM	Commission	Fee tier parameters immutable — requires redeployment to adjust	Resolved
`M-03`	MEDIUM	Cross	Staking contract address changeable without timelock	Resolved

Detailed Findings

CRITICAL C-01 Staking

Unstake accounting corruption via storage pointer after delete

unstake() reads s.amount from a storage pointer after calling delete on the struct. The storage is zeroed, so totalStaked subtraction uses 0 instead of the original amount, permanently corrupting global tracking and diluting rewards.

Resolution: Save original s.amount to a local variable before delete, use it for both return and tracking deduction.

HIGH H-01 Commission

Reputation recorded before fee transfer enables state inconsistency

pickWinner() records reputation completion before USDC transfers. If any transfer fails, reputation state is mutated for a completion that never paid out.

Resolution: Reorganized transfer order. Combined with nonReentrant, ensures all transfers complete atomically.

HIGH H-02 Staking

Reward pool receive() has no minimum totalStaked guard

Between deployment and first stake, totalStakedGlobal == 0. All rewards sent to receive() accumulate in rewardPool but never attributed to accRewardPerStake. First staker captures all accumulated rewards.

Resolution: Added check: if totalStakedGlobal == 0, hold rewards in pool without updating accumulator.

Invariant Verification

#	Invariant	Holds	Notes
1	`sum of all stakes[_agent][_] == totalStaked[_agent]`	Yes	Per-agent accounting consistent
2	`sum of all totalStaked == totalStakedGlobal`	Yes	Global sum matches per-agent sums
3	`rewardPool >= sum of all pendingReward(_agent, _staker)`	Yes	Reward pool covers all claims
4	`penalty == 0 \|\| scoreDrop >= 30%`	Yes	Penalty only when threshold met
5	`commissionFee <= budget * 5%`	Yes	Fee never exceeds max tier

Positive Security Properties

Weighted Reputation (sqrt scaling) prevents capital-based domination

Penalty mechanism aligns incentives — slashed stakes go to reward pool

Solady library stack — gas-optimized, battle-tested, 2-step ownership transfer

CEI pattern on every external call path, combined with nonReentrant

StreamPay budget capping prevents cross-stream fund leakage

No upgradeable proxies — immutable deployment, no proxy admin risks

USDC-native architecture eliminates ERC-20 approval race attack surface

Deployed Contracts

Contract	Address
AgentNFT	`0x24fe733E7ed1DbaD56CBFb2973367215756a7F83`
CollectionFactory	`0x2F847010d61A386229E82d14A9968F96eAA12d16`
Marketplace	`0xe262dFC38F2C9e95a46Dd5D56Ee1294d88d75923`
Commission	`0x50c216051Be1294A08dFa151fD6ed2B56c089d15`
Reputation	`0xD8B16882984Fc207FD92D20c4Da1947BAd863f80`
Staking	`0x5094d1Fab8c6EB3B14526e7021824F9fa6a29cba`
StreamPay	`0x402F6E37e2B49cbc755711409bD9958E3bF7Ec2B`

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