Project 14: Web Terminal (xterm.js Backend)

A web-based terminal using xterm.js in the browser and a Go/Python backend that manages PTY connections.

Quick Reference

Attribute Value
Primary Language JavaScript/TypeScript + Go
Alternative Languages Python, Rust (backend)
Difficulty Level 3: Advanced (The Engineer)
Time Estimate 2-3 weeks
Knowledge Area WebSockets / Terminal Over Network
Tooling Web Terminal
Prerequisites Basic web development, Projects 1-4

What You Will Build

A web-based terminal using xterm.js in the browser and a Go/Python backend that manages PTY connections.

Why It Matters

This project builds core skills that appear repeatedly in real-world systems and tooling.

Core Challenges

  • WebSocket protocol → Bidirectional communication
  • PTY management on server → Multiple concurrent sessions
  • Resize handling → SIGWINCH over network
  • Authentication → Secure access to shell
  • Latency → Making it feel responsive

Key Concepts

Real-World Outcome

$ ./webterm --port 8080

[WEBTERM] Listening on http://localhost:8080
[WEBTERM] Open browser to access terminal

# In browser at localhost:8080
# Full terminal in the browser!
# Can run vim, htop, ssh
# Multiple tabs supported

Implementation Guide

  1. Reproduce the simplest happy-path scenario.
  2. Build the smallest working version of the core feature.
  3. Add input validation and error handling.
  4. Add instrumentation/logging to confirm behavior.
  5. Refactor into clean modules with tests.

Milestones

  • Milestone 1: Minimal working program that runs end-to-end.
  • Milestone 2: Correct outputs for typical inputs.
  • Milestone 3: Robust handling of edge cases.
  • Milestone 4: Clean structure and documented usage.

Validation Checklist

  • Output matches the real-world outcome example
  • Handles invalid inputs safely
  • Provides clear errors and exit codes
  • Repeatable results across runs

References

  • Main guide: TERMINAL_EMULATOR_DEEP_DIVE_PROJECTS.md
  • N/A (xterm.js docs + WebSocket RFC)