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Bun: The Complete Runtime

A deep, end-to-end tour of Bun — from the WebSocket compression feature that made me write this course outward to the entire runtime. 60+ lessons covering Bun.serve (HTTP + WebSockets + TLS + cookies + SSE), Bun.file / Bun.write / FileSink, bun:sqlite (transactions + WAL + serialize), the shell ($), Bun.spawn + IPC + PTY, hashing & passwords, the Jest-compatible test runner, the bundler, --compile single-file executables, macros, plugins, cron, glob, FFI, workers, Redis. Every code example is verified against bun.com/docs. Capstone: a production WebSocket chat with compression + SQLite persistence, ready to --compile and deploy.

  • Bun
  • 88 lessons
  • ~18 hours
  • Free
  • by Fishbones

Learn Bun for free on Libre Academy with the Bun: The Complete Runtime course: 88 interactive lessons you complete by writing real code in a built-in editor, graded instantly by hidden tests. No paywall, no sign-up — it runs in your browser and the free desktop app.

What you get

  • Hands-on lessons with a real editor and instant, test-graded feedback.
  • Free and open source — no account required to start.
  • Runs in your browser, and offline in the free desktop app.
  • Bun runs in your browser.

What's inside

  • Why Bun
  • Runtime fundamentals
  • HTTP servers (Bun.serve)
  • WebSockets — including compression
  • File I/O and streams
  • SQLite (bun:sqlite)
  • Shell ($) and subprocesses
  • Hashing and passwords
  • The Bun test runner
  • Bundler and single-file executables
  • Production essentials
  • Capstone: real-time chat with compression

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