token-compatibilitylisted
Install: claude install-skill iktok90-design/ai-smart-contract-auditor
# Token compatibility detection
## When this applies
- Any ERC-20 integration: lending, AMM, vault, staking, bridge
- Balance-based accounting (`balanceOf(this) - prevBalance`)
- Decimal scaling between tokens
- Cross-chain bridges with various token implementations
- Aggregators / routers handling user-supplied tokens
## Detection patterns
### Fee-on-transfer assumed away (HIGH)
```solidity
uint256 before = token.balanceOf(address(this));
token.transferFrom(user, address(this), amount);
shares = amount * X / Y; // ← uses `amount`, not actual received
```
Tokens like USDT (when fee enabled), SafeMoon, etc. take a fee. Use `balanceOf(this) - before` as the effective amount.
### Rebasing token accounting (HIGH)
stETH, aUSDC, AMPL — balances change without `transfer`. Vaults assuming `balanceOf` ≡ deposit will mis-account. Either don't accept rebasing tokens, or use share-based accounting (wstETH-style wrappers).
### Non-standard return values — USDT (HIGH)
USDT's `transfer` does NOT return bool (pre-`SafeERC20` use breaks):
```solidity
bool ok = IERC20(usdt).transfer(to, amt); // ← reverts: ABI mismatch
```
Use OZ `SafeERC20` which uses low-level call + return-data inspection.
### Blacklistable tokens (HIGH)
USDC, USDT can blacklist addresses. If a user gets blacklisted after deposit, the protocol may be unable to return funds → other users' funds stuck if pooled.
### Pausable tokens (HIGH)
USDC, USDT can pause transfers. Protocol functions that must succeed (l