Smart Contract Developer

Download SKILL.mdGet Murage How skills work

Open source. macOS, Windows and Linux.

At a glance

What it is

Solidity smart contract development expertise covering language fundamentals, design patterns, gas optimization, common vulnerabilities (reentrancy, overflow, front-running), auditing techniques, testing with Foundry and Hardhat, and deployment best practices for EVM-compatible chains.

A skill is a written procedure a bot loads when a job calls for it. This one is a single file, SKILL.md, and the whole file is on this page.

File: SKILL.md
Length: 464 lines2,203 words, about 11 min read
Category: Emerging techblockchain and web3
Level: Advanced
License

More emerging tech skills.

The full skill.

The whole file, exactly as it downloads. Read it before you rely on it.

SKILL.md

464 lines · 2,203 words

Download

Smart Contract Developer

You are an expert Solidity smart contract developer with deep knowledge of the Ethereum Virtual Machine, security best practices, gas optimization, and the full development lifecycle from writing to auditing to deploying production-grade smart contracts.

IMPORTANT DISCLAIMER: Smart contracts handle real financial value. Bugs can lead to irreversible loss of funds. This skill provides educational guidance and development patterns only. Always engage professional auditors before deploying contracts that manage significant value. Never deploy unaudited code to mainnet with real funds.

Put this skill to work.

Questions.

What is the Smart Contract Developer skill?

How much does it cost?

Nothing. It ships with Murage, which is open source. Your bots run on the AI plan you already have.

Can I change it?

Yes. Open it in Settings → Skills to read, edit or duplicate it. Skill Guard scans it again after every edit.

Give your first job to Murage.

Download the app, connect the AI you already pay for, and tell your Chief of Staff what needs doing. Plan on about ten minutes from install to a working team.

Download Murage

No account needed · Runs on the AI plan you already pay for

Feature	Details
Custom errors	`error InsufficientBalance(uint256 available, uint256 required);` -- cheaper than revert strings
Checked arithmetic	Overflow/underflow reverts automatically in 0.8+ (use `unchecked {}` only when provably safe)
User-defined value types	`type TokenId is uint256;` for type safety
Immutable variables	`immutable` set once in constructor, stored in bytecode, cheaper than storage reads
Constants	`constant` for compile-time values, zero gas cost

Vulnerability	Detection	Mitigation
Reentrancy	External calls before state updates	CEI pattern + `nonReentrant` modifier
Integer overflow	Solidity <0.8 without SafeMath	Use Solidity 0.8+ (built-in checks)
Access control	Missing `onlyOwner` / role checks	OpenZeppelin `AccessControl`
Front-running	Unprotected swaps, auctions	Slippage limits, commit-reveal, Flashbots
Oracle manipulation	Single-source spot prices	Chainlink oracles, TWAP
Unchecked return values	Ignoring `transfer()` return	Use `SafeERC20.safeTransfer()`
Denial of service	Unbounded loops, external call in loop	Pull pattern, gas limits
Storage collision (proxies)	Misaligned storage slots	ERC-1967 storage slots

Operation	Approximate Gas Cost
SSTORE (cold, zero to non-zero)	20,000
SSTORE (warm, non-zero to non-zero)	2,900
SLOAD (cold)	2,100
SLOAD (warm)	100
Memory expansion (per word)	3
Calldata (per non-zero byte)	16
Calldata (per zero byte)	4
ETH transfer	21,000 (base)
Contract creation	32,000 (base)
LOG (per topic)	375

Smart Contract Developer

More emerging tech skills.

The full skill.

Smart Contract Developer

Put this skill to work.

Questions.

Give your first job to Murage.

Search murage.ai

Smart Contract Developer

More emerging tech skills.

The full skill.

Smart Contract Developer

Put this skill to work.

Questions.

Give your first job to Murage.

Create a bot and use this skill.

Ask Ember to create the bot

Open the bot’s skills

Find Smart Contract Developer and switch it on

Ask the bot for the job

About this skill.

Questions to Ask the User First

Solidity Fundamentals

Contract Structure

Key Language Features (Solidity 0.8+)

Common Vulnerability Patterns

1. Reentrancy

2. Access Control Flaws

3. Front-Running / MEV

4. Oracle Manipulation

Vulnerability Quick Reference

Gas Optimization

Storage Optimization

Common Gas Savings

Gas Comparison Reference

Testing with Foundry

Security Audit Checklist

Access Control

Reentrancy

Input Validation

Token Handling

Economic Security

Upgradeability (if using proxies)

Deployment

Deployment Checklist

Process

Output Format

Edge Cases

Example