TL;DR: CLAUDE.md is prose. project.faf is the specification layer — structured, scored, synced in 10ms. IANA-registered format. Now verified on Bun with 35 compatibility tests. Zero code changes.

MD explains. FAF defines. AI consumes.

Anthropic bought Bun. Claude Code ships as a Bun single-file executable. faf-cli runs inside Claude Code. We aligned.

Result: every faf-cli command works through bunx out of the box. The compiled dist/ is CommonJS — Bun handles it natively. No code changes. No shims. No polyfills.

Try It

bunx faf-cli auto
npx faf-cli auto

One command: scans your project, creates project.faf, syncs CLAUDE.md, scores AI-readiness. No install.

More commands:

bunx faf-cli git <url>

Instant context for any GitHub repo. No clone. 2 seconds.

bunx faf-cli bi-sync

Keeps project.faf ↔ CLAUDE.md in sync. ~10ms.

Three Install Paths

bunx faf-cli auto                  # Bun
npx faf-cli auto                   # npm
brew install faf-cli && faf auto   # Homebrew

All three download from the npm registry. Same package. Same counter.

Now you can have a bun with your brew.

🥐 ☕️

The Dog-Food

We ran bunx faf-cli auto on faf-cli itself:

  • 14 formats detected by TURBO-CAT
  • Full stack analysis — CLI/TypeScript/tsc/npm/Node.js
  • 100% Trophy — Gold Code
  • 0.5 seconds

35 Bun Compatibility Tests

WJTTC Bun suite — 5 tiers, all passing:

  • Tier 1 (Brake): Top 6 commands via bunx
  • Tier 2 (Engine): Zero native addons + Node.js API compat
  • Tier 3 (Aero): Sub-second performance on every command
  • Tier 4 (Telemetry): bun.lockb + bunfig.toml detection
  • Tier 5 (Championship): Dog-food — 100% Trophy via Bun

The only native addon in the entire dependency tree is fsevents — a macOS-only optional dev dependency from Jest. Not a runtime dependency. Not loaded by faf-cli. Waved right past.

The Numbers

  • v5.0.6 — Released March 13, 2026
  • 1,143/1,143 — Tests passing (50 suites)
  • 35 — Bun compatibility tests (new)
  • 100% — Trophy score (Gold Code)
  • 0.5s — bunx faf-cli auto (dog-food)
  • 64 — CLI commands
  • 0 — Code changes for Bun compat

What's Next

Phase 2: bun build --compile → standalone binary. Same way Claude Code ships. Single file, zero dependencies, Homebrew distribution.

Related

The faf auto Edition — the command that started the 0.5s story.

Your CLAUDE.md Is Not a Foundation — why structured context beats prose.

Built with .faf ☑️ Best context under the Bun. 🥐 ☕️