rtk

What it does

Sits between the shell and the model, filtering and compressing command output so an agent reads a fraction of the tokens it otherwise would — the project claims up to 90% on supported commands, of which there are over 100. It ships as a single Rust binary with Homebrew, script, Cargo and pre-built install routes, and documentation in several languages including Japanese. Savings depend heavily on which commands you run, so treat the headline figure as a ceiling. Apache-2.0.

Summary based on the project's own description. The Japanese page has a fuller beginner guide: setup difficulty, what to prepare, and a step-by-step start.

Screenshots & visuals

Before you start

• Setup difficultyEasy to start
• Command lineRequired
• API keyNot required
• Sends data onlineNo

Judged automatically from the project's own metadata. Always confirm on the official page.

rtk FAQ

Is rtk free?

Yes. It runs on your own machine, so there is no usage-based cost either.

Do I need to install anything or write code to use rtk?

It needs the command line. If you are not comfortable typing commands, expect to get stuck during setup.

Does rtk work on a phone?

No. It needs a computer.

Can I use rtk commercially?

The licence is Apache-2.0, which permits commercial use. Conditions such as keeping the copyright notice still apply, so read the licence text before shipping it inside something.

How it compares

The conditions that decide whether you can actually use it, side by side.

"Sends data out" means your input is uploaded to someone's server. Pick "No" when the material cannot leave your organisation.

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