Vibe Coding: Smart Contracts at Hackathon Speed
Build Secure Smart Contracts with AI - Fast & Safe
Today's Plan
1. What is Vibe Coding
for smart contracts
2. AI Tools for Solidity
Foundry, Hardhat, more
3. Solidity Prompts That Work
copy-paste examples
4. Step-by-Step Workflow
exact process
5. Security with AI
critical considerations
6. Demo Prep
what judges care about
Part 1: What is Vibe Coding
What is Vibe Coding for Smart Contracts?
Not random. Strategic speed with AI. You review security.
It's simple:
- ▹Use AI to write Solidity faster
- ▹Build contract functions quickly
- ▹Compile and test immediately
- ▹Deploy and demo often
Part 1: What is Vibe Coding
Old Way vs. Vibe Coding for Smart Contracts
❌ Old Way
Read Solidity docs → Write functions → Compile → Debug → Fix Takes hours. One contract.
✅ Vibe Coding
Tell AI what you want → Review security → Adjust → Deploy Takes minutes. Multiple contracts.
Part 2: AI Tools
Essential AI Tools for Smart Contracts
All work together. Use all of them.
Get these now:
- ▹🔧 Cursor IDE - Best for Solidity coding with AI
- ▹🔧 GitHub Copilot - Auto-complete for Solidity
- ▹🔧 Claude / GPT / GLM - For smart contract explanations
- ▹🔧 Foundry - Fast compilation and testing
- ▹🔧 Slither - AI-assisted security analysis
Part 3: AI Prompts
Good Prompt = Good Smart Contract
More details = better results. Always specify security requirements.
Structure your Solidity prompts:
- ▹1. Role: "Act as Solidity auditor"
- ▹2. Context: "Building ERC20 token for hackathon"
- ▹3. Task: "Create a standard ERC20 implementation"
- ▹4. Requirements: "OpenZeppelin v5, gas optimized, Solidity 0.8.20"
Part 3: AI Prompts
Bad vs. Good Prompts
❌ Bad Prompt
"Make a token contract" No standard specified No features listed No version mentioned Vague and generic AI has to guess everything
✅ Good Prompt
"Act as Solidity expert. Create an ERC20 token using OpenZeppelin v5. Features: mint, burn, transfer. Gas optimized. Solidity 0.8.20." Role: Solidity expert Standard: OpenZeppelin v5 Features: Listed Context: Hackathon demo
Part 3: AI Prompts
Good vs. Better Prompts
More details = fewer iterations = faster deployment.
Good prompt is okay, but better is faster:
- ▹✅ GOOD: "Solidity expert. Create ERC20 with OpenZeppelin v5. Gas optimized. Solidity 0.8.20."
- ▹✅ BETTER: "Solidity auditor. ERC20 implementation. - OpenZeppelin v5 - Solidity 0.8.20 - Gas optimized - Mint function with access control - Burn function - Transfer function - Events for all operations - SafeMath usage - Reentrancy protection"
Part 3: AI Prompts
Solidity Prompt Templates
Save these. Modify for your project.
Use these patterns:
- ▹"Create a [contract type] using [standard]. Features: [list]. Gas optimized. Solidity [version]."
- ▹"Debug this contract. It should [expected behavior]. Here's error: [paste error]."
- ▹"Refactor this for [gas optimization/security]. Keep functionality same."
- ▹"Generate Foundry tests for [function]. Cover reentrancy, overflow, underflow cases."
Part 4: Workflow
The Smart Contract Vibe Coding Loop
Each cycle = 2-5 minutes. Not 30 minutes.
Repeat this 20 times:
- ▹1. Say what contract does (to AI)
- ▹2. AI writes Solidity
- ▹3. Compile and test
- ▹4. Fix compilation errors
- ▹5. Move to next function
Part 4: Workflow
Step 1: First Working Contract (30 min)
Deployed is better than perfect.
Build something that compiles:
- ▹AI: "Create a basic [ERC20 token] with [mint function]"
- ▹Accept basic implementation
- ▹Use OpenZeppelin for security
- ▹No complex features
- ▹Just compile and deploy to testnet
Part 4: Workflow
Step 2: Add Functions (1-2 hours)
Never build 5 functions at once.
One function at a time:
- ▹Pick most important function
- ▹Prompt AI: "Add [function] to existing contract"
- ▹Compile and test
- ▹Then pick next function
Part 4: Workflow
Step 3: Security & Optimization (last hour)
Skip optimization if core functions not done.
Only if you have time:
- ▹AI: "Run Slither security audit"
- ▹AI: "Optimize for gas"
- ▹AI: "Add access control modifiers"
- ▹Test all functions with Foundry
Part 5: Mistakes
Common Smart Contract Mistakes
❌ Don't Do This
Plan for hours before coding Build custom ERC20 from scratch Gas optimization first Add complex auth system Write all tests yourself
✅ Do This Instead
Code immediately Use OpenZeppelin standards Basic functions first Skip complex auth for now AI generates tests, you review
Part 5: Security
AI Security Mistakes to Avoid
You are the auditor. AI drafts. You review.
Critical warnings:
- ▹❌ Deploy AI code without reading it
- ▹❌ Skip security review of AI suggestions
- ▹❌ Trust AI 100% for critical functions
- ▹❌ Not checking for reentrancy/overflow bugs
- ▹❌ Using vague security prompts
Part 5: Security
Security Checklist for AI-Generated Contracts
Never deploy without human security review.
Does AI use OpenZeppelin standard contracts?
Are require() statements checking msg.sender?
Are overflow/underflow checks present?
Is there reentrancy protection on external calls?
Are events emitted for all state changes?
Did you run Slither security analysis?
Part 6: Demo
What Judges Actually Care About
Complex contracts are bonus. Working is required.
Demo success = project success:
- ▹✅ Problem is clear
- ▹✅ Smart contract compiles and works
- ▹✅ Demo is 3 minutes or less
- ▹✅ No bugs in testnet demo
- ▹✅ Story makes sense
Part 6: Demo
Demo Script Template
Practice until you can do it without thinking.
Follow this 4-minute script:
- ▹1. Problem (30 sec): "Users can't vote in decentralized way"
- ▹2. Solution (2 min): "Here's our governance contract. Mint, vote..."
- ▹3. Features (1 min): "Call vote function. See result."
- ▹4. Value (30 sec): "True DAO voting, gas efficient"
Part 6: Demo
Demo Day Checklist
One demo failure = lost.
Deploy to testnet before demo
Have backup screenshots of successful transactions
Test on projector/speaker beforehand
Know who explains each function
Prepare for security questions
Have testnet explorer URLs ready
Part 7: Your Turn
Real Example: ERC20 Token in 15 Minutes
4 prompts. 15 minutes. Deployed contract.
Try this now:
- ▹1. AI: "Create ERC20 with OpenZeppelin v5. Mint, burn, transfer."
- ▹2. AI: "Add access control to mint function"
- ▹3. AI: "Add events for all operations"
- ▹4. AI: "Generate Foundry tests"
Part 7: Your Turn
Your Hackathon Plan
Practice today. Win tomorrow.
Today:
- ▹✅ Download Cursor IDE
- ▹✅ Install Foundry or Hardhat
- ▹✅ Practice 5 Solidity prompts
- ▹✅ Build a simple ERC20
- ▹✅ Time yourself
Part 7: Your Turn
Quick Reference: Solidity Prompt Patterns
Take a picture. Use tomorrow.
🔧 Scaffolding:
- ▹"Create [contract type] using [standard]. Features: [list]. Gas optimized."
🐛 Debugging:
- ▹"Fix this Solidity error: [paste]. Contract: [paste]."
✨ Functions:
- ▹"Add [function] to [contract]. Handle [edge case]. Access control included."
🔒 Security:
- ▹"Review for [reentrancy/overflow]. Add checks. Use modifiers."
🧪 Testing:
- ▹"Generate Foundry tests for [function]. Cover [edge cases]."
Part 7: Your Turn
Team Roles (Simple Version)
Rotate if needed. Keep everyone busy.
Divide work:
- ▹🎯 Vision: Keeps contract focused
- ▹⚡ Builder: Writes Solidity with AI
- ▹🔧 Fixer: Compiles and tests
- ▹🎤 Presenter: Prepares demo
Part 7: Your Turn
Recap: The Formula
Compare to old way: 4-6 functions. You're 10x faster.
Smart Contract Vibe Coding Formula:
- ▹1. Clear goal
- ▹2. One function
- ▹3. AI writes Solidity
- ▹4. Compile and test
- ▹5. Fix if errors
- ▹6. Repeat
Speed Stats:
- ▹Time per function: 5-10 minutes
- ▹Functions per hour: 6-12
- ▹Total functions in hackathon: 40-80
Part 7: Your Turn
Final Message
Hackathons = Speed + Working Contracts + Security Review
AI makes speed possible.
You direct. AI writes.
You audit security.
You win.
🔥 Go deploy something. Fast and Safe. 🔥