DHH: Fable One-Shotted a Rust Rewrite in 11M Tokens
Published: 2026-08-10 · Author: Yash Thakker
On August 10, 2026, Ruby on Rails creator DHH posted on X that Fable “one-shotted” a full Rust rewrite of TerminalTextEffects — a Python terminal-animation library by developer ChrisBuilds — using 11 million tokens in a single pass. His numbers: startup time down from 87ms to 2ms, rendering speed up 9.6x, zero runtime dependencies, and a 3MB single-file executable replacing a Python installation entirely. The post embedded a video showing all 37 of the library’s built-in effects animating the full Omarchy ASCII logo through the new Rust binary. It crossed 227,900 views within hours.
Headline Numbers
| Metric | Python (before) | Rust (after) | Delta |
|---|---|---|---|
| Startup time | 87ms | 2ms | ~43x faster |
| Rendering speed | Baseline | 9.6x baseline | 9.6x faster |
| Runtime dependencies | 0 third-party packages, but requires a Python interpreter | 0 crates, no interpreter needed | Interpreter eliminated |
| Distribution | Python package + interpreter | 3MB single static executable | No runtime install step |
| Effects verified | 37 | 37 | Full parity claimed |
DHH’s video demo ran all 37 effects against the “full Omarchy ASCII logo” — Omarchy being DHH’s own Arch-based, Hyprland desktop distro — as the visual proof of parity.
Context
TerminalTextEffects (repo alias ttfx, also called TTE) is a real, actively maintained open-source project — a terminal visual-effects engine and Python library that animates text with effects like beams, burn, matrix rain, and thunderstorms. It’s MIT-licensed, sits at roughly 4,100 GitHub stars, and the Python original already shipped with zero third-party dependencies.
The 87ms → 2ms jump is structurally predictable: even a Python script with zero third-party dependencies still pays CPython’s fixed startup tax on every invocation. A statically compiled Rust binary skips that tax entirely.
Replies to DHH’s post noted this “would be one of the easier things to do” because the spec was fully written already, in full detail, as working Python code — a small, well-bounded surface area with no undocumented behavior.
“One-shotted” describes the orchestration shape (single session, not a coordinated multi-agent campaign), not a claim that the first draft compiled with no self-correction. 11 million tokens is enough for a large number of internal edit-compile-test cycles within one continuous run.
At Fable 5’s published rates — 50 per million output tokens — an 11M-token task lands somewhere in the tens-to-low-hundreds-of-dollars range depending on the input/output split.
KuCoin reported on August 16 that the entire process took 3 hours and 11 minutes, with 21,000 lines of main Rust code — nearly identical in size to the original Python version. DHH has shifted to an “agent-first” approach and predicts that few will manually code within five years.
Primary sources: DHH on X, August 10, 2026 · TerminalTextEffects on GitHub · omacom-io/ttfx (Rust port repo created August 9, 2026)