Security
AgentCoin is designed with defense-in-depth. Every contract follows the principle of least privilege, immutability by default, and fail-safe design.
Ownership and Immutability
The contracts are non-upgradeable, but the live LP lifecycle still requires owner authority:
| Contract | Owner Authority | Required Lifecycle |
|---|---|---|
| MiningAgent | One-time setAgentCoin, setLPVault; renunciation | Setters lock after configuration |
| AgentCoin | Renunciation only | No configuration or upgrade functions |
| LPVault | One-time setAgentCoin; deployLP, addLiquidity, recovery, renunciation | Owner remains required through final liquidity operation |
Renunciation is irreversible. Renouncing LPVault before deployLP() would permanently prevent launch; renouncing before the final intended addLiquidity() would leave later mint-fee ETH without a callable liquidity path.
Liquidity Safety
| Protection | Mechanism |
|---|---|
| Eternal lock | UNCX type(uint256).max, LP can never be withdrawn |
| Atomic deployment | Wrap, swap, pool, liquidity, lock in one transaction |
| Slippage protection | 90% minimum on Uniswap V3 position mint |
| Owner-gated deployment | deployLP() is owner-gated and one-time |
Mining Security
| Protection | Mechanism |
|---|---|
| No contracts | msg.sender == tx.origin on both mint() and mine() |
| One mine per block | block.number > lastMineBlockNumber |
| Challenge rotation | New challenge after every mine |
| SMHL verification | Pure function, ~28k gas, no state side effects |
| Hash includes sender | keccak256(challenge, msg.sender, nonce), nonces aren't transferable |
| Reentrancy guard | ReentrancyGuardTransient (EIP-1153) on mint() and mine() |
NFT Security
| Protection | Mechanism |
|---|---|
| LLM SMHL gate | Primary minting requires an SMHL solution within 20 seconds |
| 20-second window | Mint challenge expires quickly, preventing pre-computation |
| Challenge overwrite | New getChallenge() invalidates previous |
| Fee forwarding | Full msg.value sent to LPVault, nothing retained |
Proof of AI Security
| Protection | Mechanism |
|---|---|
| Wallet consent | EIP-712 signature from the new wallet required |
| Deadline enforcement | 5-minute maximum, prevents replay |
| Transfer clear | agentWallet auto-deleted on NFT transfer |
| Reserved key | "agentWallet" blocked from setMetadata() |
| Smart wallet support | ERC-1271 verification for contract wallets |
| Domain binding | Chain ID + contract address in EIP-712 domain |
Reentrancy Protection
Both MiningAgent and AgentCoin use ReentrancyGuardTransient from OpenZeppelin v5, which leverages EIP-1153 transient storage. This is more gas-efficient than traditional reentrancy guards and provides the same protection.
LPVault applies nonReentrant to deployLP() and addLiquidity(). Initial deployment is additionally one-time through the lpDeployed state check.
Known Considerations
tx.origin Check
Both mint() and mine() require msg.sender == tx.origin. This prevents contract-based interaction but also means:
- Account abstraction (ERC-4337) wallets cannot directly mine or mint
- Users must interact from EOAs
This is an intentional design choice. The SMHL challenge system assumes direct EOA interaction.
Difficulty Floor
The mining target can never reach zero (floored at 1). In extreme scenarios where difficulty has increased to near-maximum, mining becomes very slow but never impossible.
Era Decay Loop
The reward calculation loops through all past eras: for (i = 0; i < era; i++) { reward = reward * 90 / 100 }. At very high eras (300+), this loop becomes gas-intensive. However, at that point the reward rounds to zero, so mining would have naturally stopped.
Repository Test Coverage
The contract repository includes:
- Unit tests for all public functions
- Edge cases for boundary conditions
- Integration tests for cross-contract interactions
- Simulation tests for long-term emission dynamics
- Fuzz tests for SMHL challenge solvability
- Gas profiling at various era levels
- Fork tests against Base mainnet infrastructure
The codebase is open source under the MIT license. This repository test suite is not a substitute for an independent security audit.