AI is writing more of your code. Claude Code oneshotting, ChatGPT copy and paste, forgetting what an IDE looks like. But running code you didn't write is risky. What if there are bugs? What if there are security vulnerabilities?

Before you YOLO everything into production, Vercel Sandbox lets you execute untrusted code in isolated microVMs that spin up in milliseconds. In this course, you'll build a CLI agent that doesn't just read code, it actually runs it, safely.

What you'll build

A CLI tool that accepts a GitHub repo URL, clones the repository into an isolated Sandbox environment, runs its test suite, and uses AI to review the code for security and quality issues. By the end, you'll have a tool that combines static analysis with dynamic test execution into a unified review.

What you'll learn

This course covers 5 sections that progressively build a CLI code review agent:

Section 1: Sandbox Foundations - Create sandboxes, run commands, clone repos, and read files in isolated environments
Section 2: Building the CLI - Set up a CLI project with commander, validate GitHub URLs, and wire up the Sandbox workflow
Section 3: AI-Powered Analysis - Use AI Gateway to read code files, build analysis prompts, and generate security and quality reviews
Section 4: Test Execution - Run test suites in the Sandbox, handle failures, and combine static and dynamic findings
Section 5: Production Ready - Optimize with snapshots, add error handling, and polish the output

Prerequisites

Comfortable with TypeScript and Node.js
Basic familiarity with CLI tools
Vercel account

Tech stack

@vercel/sandbox - Isolated microVMs for code execution
AI SDK with AI Gateway
TypeScript
commander - CLI framework
pnpm - Package manager
git - Repository cloning

How this course works

Build everything yourself: Type every line of code so you understand how everything works
Real code execution: Every section runs actual commands in real sandboxes
Progressive complexity: Each section adds one new capability
Production patterns only: Everything you build is something you'd actually ship

Getting started

Ready to safely execute untrusted code? Start with Sandbox Foundations to learn the basics of isolated environments.