CodexZero

Less input. Same task score.

CodexZero saves more tokens.

CodexZero recorded the largest token reduction in our completed comparisons. In the strongest repeated test, it used 15% fewer tokens and matched Codex’s task score.

Install CodexZero See the result
  • Free and open source
  • Installs beside Codex
  • Full results stay available
Highest recorded token reduction for each setup: CodexZero Max used 31 percent fewer tokens, CodexZero 15 percent fewer, RTK 8 percent fewer, regular Codex is the standard baseline, Caveman used 2 percent more, and RTK plus Caveman used 13 percent more.
Highest recorded reduction for each setup across completed benchmark runs. Benchmark summary
15%fewer tokens
Sametask score
3.89Mtokens avoided

Repeated benchmark

Less to process. No score lost.

Codex and CodexZero each completed the same 12 software tasks three times. CodexZero matched the final score while processing 3.89 million fewer tokens.

Regular Codex processed 26.58 million tokens and CodexZero processed 22.69 million while both scored 29 out of 36. CodexZero Max is projected at 19.62 million tokens using the measured Max-to-Standard ratio from the controlled comparison.
12 tasks · three runs each · 36 outcomes per setup
Cache hit ratios across every setup: regular Codex 89.8 percent, CodexZero 90.7 percent, CodexZero Max 91.6 percent, RTK 90.5 percent, Caveman 92.9 percent, and RTK plus Caveman 91.4 percent.
Terminal-Bench mini-panel · cached input tokens / total input tokens

Install

Keep Codex. Add CodexZero.

CodexZero installs beside your existing setup, so regular Codex remains available whenever you want it.

irm https://raw.githubusercontent.com/Retro2512/CodexZero/main/scripts/bootstrap.ps1 | iex
Download a release View Windows script View macOS script

Supports Windows x64, Intel Mac, and Apple silicon Mac.

After installation codex-zero run

Start the optimized CLI.

codex-zero savings

See the tokens saved on your own work.

codex-zero stock

Open regular Codex at any time.

How it works

Shorter results when they actually save tokens.

CodexZero keeps the original command result available, removes repeated text when it can, and otherwise leaves the result alone.

01

Run normally

Your commands, model, tools, and project instructions continue to work as before.

02

Remove repetition

Repeated command output can be replaced with a shorter reading copy.

03

Keep the smaller result

If nothing gets smaller, CodexZero sends the original result unchanged.

Two settings

Start with Standard.

Standard keeps Codex’s normal instructions and shortens eligible command results. It is selected by default.

Default

Standard

The setting used for the repeated 15% result.

Optional

Max Savings

A leaner setting for repeatable work. Switch modes whenever you want.

Quick answers

What you need to know.

Does CodexZero replace Codex?

No. It installs beside Codex, and codex-zero stock opens your regular setup.

What does it change?

It shortens eligible command results before the model reads them again. The full result stays available.

Will it lower my bill?

CodexZero reduces the input tokens it changes. Your actual bill or plan usage also depends on output, caching, pricing, and your workload.

Ready when you are

Use fewer tokens on your next Codex run.

Install CodexZero