Can I code this? A Code Playground for Teaching Programming
A browser code editor is genuinely buildable. Safely running untrusted code from many students at once, isolated from each other, is the same security-critical infrastructure that makes Replit a JUST PAY.
Just pay
Effort: not worth startingRunning cost: $0/mo to start
Why CanICodeThis says Just pay
A browser-based text editor with syntax highlighting is a mature, well-documented component
For your own trusted code (not many students' arbitrary submissions), a single sandboxed container is a real, bounded build
Saving and organizing personal code exercises is ordinary CRUD
The parts that'll cause problems
Safely sandboxing and executing arbitrary code from many students at once, so one person's code can't escape or affect another's, is genuine security-critical infrastructure
Supporting multiple languages, each correctly isolated, multiplies that security surface
Real-time collaborative editing (watching a student's code live) compounds an already-hard problem
How I'd build this
frontend
Next.js
database
Supabase
hosting
Vercel
MVP scope
If you proceed: a personal single-user code editor with one sandboxed container
Save and organize your own exercises
Postpone to v2
Multi-student sandboxed execution (genuinely hard — consider using an existing service instead)
Real-time instructor view of student code
What it actually costs to build
AI agent — with a subscription (Claude Pro/Max, Cursor, etc.)
$0 marginal
AI agent — pay-per-use API, no subscription
$86–$172 one-time
Hosting, once it's running
$0/mo (free tier)
Domain name, if you want your own
~$12/yr
Existing tools solving a similar problem typically run $20–$20/mo — see how they compare below.
The build prompt
Don't build multi-student code execution — the security stakes are real. For a personal code playground on your own trusted exercises, build a simple browser-based editor connected to one sandboxed container using an existing container isolation tool, not hand-rolled security boundaries. For teaching many students, an existing service is the honest answer.