---
name: Solidity Security
slug: solidity-security
category: Quality
description: Solidity Security provides patterns and checklists for writing secure Solidity smart contracts, auditing for vulnerabilities like reentrancy and integer overflow, and enforcing access control. Use it when building or reviewing DeFi protocols and preparing contracts for audit.
github: "https://github.com/wshobson/agents/tree/main/plugins/blockchain-web3/skills/solidity-security"
language: Python
stars: 38761
forks: 4132
install: "npx degit https://github.com/wshobson/agents/tree/main/plugins/blockchain-web3/skills/solidity-security ~/.claude/skills/solidity-security"
installs_to: ~/.claude/skills/solidity-security
source_path: plugins/blockchain-web3/skills/solidity-security/SKILL.md
collection_size: 25
category_size: 1354
collection_url: "https://dirskills.com/collections/wshobson/agents"
added: 2026-08-13T07:37:12.314Z
last_synced: 2026-08-13T07:37:12.314Z
canonical_url: "https://dirskills.com/skills/solidity-security"
---

# Solidity Security

Solidity Security provides patterns and checklists for writing secure Solidity smart contracts, auditing for vulnerabilities like reentrancy and integer overflow, and enforcing access control. Use it when building or reviewing DeFi protocols and preparing contracts for audit.

**Install:**

```bash
npx degit https://github.com/wshobson/agents/tree/main/plugins/blockchain-web3/skills/solidity-security ~/.claude/skills/solidity-security
```

## README

# Solidity Security

Master smart contract security best practices, vulnerability prevention, and secure Solidity development patterns.

## When to Use This Skill

- Writing secure smart contracts
- Auditing existing contracts for vulnerabilities
- Implementing secure DeFi protocols
- Preventing reentrancy, overflow, and access control issues
- Optimizing gas usage while maintaining security
- Preparing contracts for professional audits
- Understanding common attack vectors

## Detailed patterns and worked examples

Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient.

## Testing for Security

```javascript
// Hardhat test example
const { expect } = require("chai");
const { ethers } = require("hardhat");

describe("Security Tests", function () {
  it("Should prevent reentrancy attack", async function () {
    const [attacker] = await ethers.getSigners();

    const VictimBank = await ethers.getContractFactory("SecureBank");
    const bank = await VictimBank.deploy();

    const Attacker = await ethers.getContractFactory("ReentrancyAttacker");
    const attackerContract = await Attacker.deploy(bank.address);

    // Deposit funds
    await bank.deposit({ value: ethers.utils.parseEther("10") });

    // Attempt reentrancy attack
    await expect(
      attackerContract.attack({ value: ethers.utils.parseEther("1") }),
    ).to.be.revertedWith("ReentrancyGuard: reentrant call");
  });

  it("Should prevent integer overflow", async function () {
    const Token = await ethers.getContractFactory("SecureToken");
    const token = await Token.deploy();

    // Attempt overflow
    await expect(token.transfer(attacker.address, ethers.constants.MaxUint256))
      .to.be.reverted;
  });

  it("Should enforce access control", async function () {
    const [owner, attacker] = await ethers.getSigners();

    const Contract = await ethers.getContractFactory("SecureContract");
    const contract = await Contract.deploy();

    // Attempt unauthorized withdrawal
    await expect(contract.connect(attacker).withdraw(100)).to.be.revertedWith(
      "Ownable: caller is not the owner",
    );
  });
});
```

## Audit Preparation

```solidity
contract WellDocumentedContract {
    /**
     * @title Well Documented Contract
     * @dev Example of proper documentation for audits
     * @notice This contract handles user deposits and withdrawals
     */

    /// @notice Mapping of user balances
    mapping(address => uint256) public balances;

    /**
     * @dev Deposits ETH into the contract
     * @notice Anyone can deposit funds
     */
    function deposit() public payable {
        require(msg.value > 0, "Must send ETH");
        balances[msg.sender] += msg.value;
    }

    /**
     * @dev Withdraws user's balance
     * @notice Follows CEI pattern to prevent reentrancy
     * @param amount Amount to withdraw in wei
     */
    function withdraw(uint256 amount) public {
        // CHECKS
        require(amount <= balances[msg.sender], "Insufficient balance");

        // EFFECTS
        balances[msg.sender] -= amount;

        // INTERACTIONS
        (bool success, ) = msg.sender.call{value: amount}("");
        require(success, "Transfer failed");
    }
}
```