Mojo Playground

A web-based playground for the Mojo programming language, built with Go, React, and Docker.

Features

• Monaco Editor: High-quality code editing with syntax highlighting.
• Sandboxed Execution: Code runs inside isolated Docker containers with resource limits.
• Snippet Sharing: Share your code snippets via unique URLs.

Prerequisites

• Docker
• Go 1.22+
• Node.js 18+
• Modular Auth Key (Required for the Mojo SDK)

Setup

1. Build the Mojo Sandbox

The sandbox uses the public Mojo nightly builds via uv. No API key is required for this step!

docker build -t mojo-runner -f docker/Dockerfile.mojo .

2. Start the Backend

cd backend
go run main.go

The API will start on http://localhost:8080.

3. Start the Frontend

cd frontend
npm install
npm run dev

The playground will be available at http://localhost:5173.

modman CLI

The modman CLI allows you to interact with the playground from your terminal.

Installation

cd cli
go build -o modman
mv modman /usr/local/bin/ # optional

Usage

• Run a local file remotely: modman run hello.mojo
• Share a local file: modman share hello.mojo
• Ask AI to fix a file: modman fix hello.mojo "compilation error message"

Project Structure

• backend/: Go (Gin) API for execution and storage.
• frontend/: React + Tailwind CSS + Monaco Editor.
• docker/: Dockerfile for the Mojo execution environment.

Contributing

We welcome contributions to the curriculum!

Adding a New Lesson

1. Navigate to the /curriculum directory in the project root.
2. Duplicate starter-template.md.
3. Fill in the metadata (YAML frontmatter) and the content.
4. Add your Mojo code within the ```mojo block.
5. Submit a Pull Request!

Lessons are automatically loaded by the frontend. Ensure your code follows the latest Mojo 1.0 (2026) syntax:

• Use def for all functions.
• Use var for all variable declarations (let is removed).
• Add raises to functions that can throw errors.

License

MIT