Solidity Guardian 🛡️

Security analysis for Solidity smart contracts. Find vulnerabilities, get fix suggestions, follow best practices.

Quick Start

# Analyze a single contract
node skills/solidity-guardian/analyze.js contracts/MyContract.sol

# Analyze entire project
node skills/solidity-guardian/analyze.js ./contracts/

# Generate markdown report
node skills/solidity-guardian/analyze.js ./contracts/ --format markdown > AUDIT.md

What It Detects (40+ Patterns)

Critical (Must Fix)

ID	Vulnerability	Description
SG-001	Reentrancy	External calls before state updates
SG-002	Unprotected selfdestruct	Missing access control on selfdestruct
SG-003	Delegatecall to untrusted	Delegatecall with user-controlled address
SG-004	Uninitialized storage pointer	Storage pointer overwrites slots
SG-005	Signature replay	ecrecover without nonce/chainId
SG-006	Arbitrary jump	Function type from user input

High (Should Fix)

ID	Vulnerability	Description
SG-010	Missing access control	Public functions that should be restricted
SG-011	Unchecked transfer	ERC20 transfer without return check
SG-012	Integer overflow	Arithmetic without SafeMath (pre-0.8)
SG-013	tx.origin auth	Using tx.origin for authentication
SG-014	Weak randomness	block.timestamp/blockhash for randomness
SG-015	Unprotected withdrawal	Withdrawal without ownership check
SG-016	Unchecked low-level call	.call() without success check
SG-017	Dangerous equality	Strict balance check (manipulable)
SG-018	Deprecated functions	suicide, sha3, throw, callcode
SG-019	Wrong constructor	Function name matches contract

Medium (Consider Fixing)

ID	Vulnerability	Description
SG-020	Floating pragma	Non-pinned Solidity version
SG-021	Missing zero check	No validation for zero address
SG-022	Timestamp dependence	Logic depends on block.timestamp
SG-023	DoS with revert	Loop with external call can revert
SG-024	Front-running risk	Predictable state changes

Low (Best Practice)

ID	Vulnerability	Description
SG-030	Missing events	State changes without events
SG-031	Magic numbers	Hardcoded values without constants
SG-032	Implicit visibility	Functions without explicit visibility
SG-033	Large contract	Contract exceeds size recommendations
SG-034	Missing NatSpec	Public functions without documentation

Usage Examples

Basic Analysis

const { analyzeContract } = require('./analyzer');

const results = await analyzeContract('contracts/Token.sol');
console.log(results.findings);

With Fix Suggestions

const results = await analyzeContract('contracts/Vault.sol', {
  includeFixes: true,
  severity: ['critical', 'high']
});

for (const finding of results.findings) {
  console.log(`[${finding.severity}] ${finding.title}`);
  console.log(`  Line ${finding.line}: ${finding.description}`);
  console.log(`  Fix: ${finding.suggestion}`);
}

Generate Report

const { generateReport } = require('./reporter');

const report = await generateReport('./contracts/', {
  format: 'markdown',
  includeGas: true,
  includeBestPractices: true
});

fs.writeFileSync('SECURITY_AUDIT.md', report);

Best Practices Checklist

When writing secure contracts, follow these guidelines:

Access Control

• [ ] Use OpenZeppelin's Ownable or AccessControl
• [ ] Apply onlyOwner or role checks to sensitive functions
• [ ] Implement two-step ownership transfer
• [ ] Consider timelocks for critical operations

Reentrancy Prevention

• [ ] Use ReentrancyGuard on all external-facing functions
• [ ] Follow checks-effects-interactions pattern
• [ ] Update state BEFORE external calls
• [ ] Use pull over push for payments

Input Validation

• [ ] Validate all external inputs
• [ ] Check for zero addresses
• [ ] Validate array lengths match
• [ ] Use SafeERC20 for token transfers

Arithmetic Safety

• [ ] Use Solidity 0.8+ or SafeMath
• [ ] Check for division by zero
• [ ] Validate percentage calculations (≤100)
• [ ] Be careful with token decimals

Upgradeability (if applicable)

• [ ] Use initializer instead of constructor
• [ ] Protect initialize from re-initialization
• [ ] Follow storage layout rules
• [ ] Test upgrade paths

Slither Integration

Guardian can run alongside Slither for comprehensive analysis:

# Combined analysis (auto-installs Slither if missing)
node skills/solidity-guardian/slither-integration.js ./contracts/ --install-slither

# Generate combined report
node skills/solidity-guardian/slither-integration.js . --format markdown --output AUDIT.md

# Guardian only (faster, no Slither dependency)
node skills/solidity-guardian/slither-integration.js ./contracts/ --guardian-only

# Slither only
node skills/solidity-guardian/slither-integration.js ./contracts/ --slither-only

Why both? - Guardian: Fast pattern matching, custom rules, no compilation needed - Slither: Deep dataflow analysis, CFG-based detection, more comprehensive

Integration with Other Tools

Hardhat

// hardhat.config.js
require('./skills/solidity-guardian/hardhat-plugin');

// Run: npx hardhat guardian

Foundry

# Add to CI
forge build
node skills/solidity-guardian/analyze.js ./src/

References

• Trail of Bits - Building Secure Contracts
• OpenZeppelin - Security Best Practices
• Consensys - Smart Contract Best Practices
• SWC Registry

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Built by Avi 🔐 | Security-first, ship always.