What is Ponytail?
Ponytail is a Claude Code skill (it works with Codex too) that installs a "lazy senior developer" mindset into the agent: efficient, not careless. Before writing anything, it climbs a short ladder — does this need to exist at all? Is it already in the codebase? Does the standard library or a native feature cover it? Can it be one line? — and stops at the first rung that works. The result is smaller, more boring, more maintainable code, produced with fewer output tokens.
Why output tokens matter
Input-focused tools can cut the noise an agent reads, but they don't touch what it writes. On code-generation tasks the response itself is a real chunk of the bill, and verbose, over-built code costs twice: once in the tokens to generate it, and again every time the agent re-reads and edits it later. Ponytail shrinks both by making "write less" the default.
How to use Ponytail with Claude Code
The simplest path is to download the Headroom app and toggle Ponytail on from the Add-ons screen — it then applies to Claude Code and Codex automatically. Ponytail is a skill, so you can also invoke it on demand with intensity levels (lite, full, ultra) when you want the agent to be especially ruthless about cutting code.
Ponytail and the rest of the stack
Ponytail is one tool in a small stack the Headroom app can run for you. Headroom compresses bulky tool output and boilerplate on the input side, RTK trims noisy terminal output, and MarkItDown converts heavy documents to clean Markdown. Ponytail covers the output side. Together they target around 50% lower token usage — roughly 2x more usage on the plan you already pay for. See the FAQ for privacy and rollout details.