RTK (Rust Token Killer): Cut the command output read by the AI assistant by up to 90%, single file Rust binary, 80,000 starsRTK（Rust Token Killer）：把 AI 助手读到的命令输出砍掉最多九成，单文件 Rust 二进制、8 万星

A large part of the AI programming assistant's input token is not the prompt you wrote, but the original output it reads back after running the command in the background.

A git diff can be hundreds of lines, a test failure with a full stack, and a Docker log that flushes tens of thousands of lines at a time - all crammed into a context window.

RTK's idea is to "sift through the model before seeing it": only the conclusive information is retained, the noise is discarded locally, the model can still understand, and the window is saved.

File class: ls and tree output changed to compact tree with number of files, cat and read replaced full text with signature and structure, grep and rg grouped by files and truncated overlong lines.

Git class: git status becomes compact statistics, git log only leaves hashes, authors and topics, git push and git commit only return one line confirmation.

Testing and building: cargo test, npm test, pytest, go test, etc. Only the failed items are retained, and the passed use cases are folded into a count.

O&M and containers: docker ps, docker images, kubectl pods, aws series commands have done field clipping and log deduplication, and will filter out key class information.

Officially, there are four sets of common strategies: intelligent filtering denoising, similarity group aggregation, on-demand truncation, and repetitive row folding counting.

Execute the initialization command once: rtk init -g For Claude Code and Copilot, add --gemini, --codex, --agent cursor, --agent windsurf and other parameters to switch the target tool.

After initialization, it writes the hook, and the git status command is automatically rewritten to rtk git status. The model gets the compressed output, so you don't need to change your habits manually.

Note that the hook only takes effect for Bash tool calls; the Read, Grep, and Glob built into Claude Code do not go through Bash. If you want to save this part of the token, use the shell command or directly call rtk read and rtk grep.

You can always execute rtk gain to open the savings board to see how much output and tokens are currently saved.

Below is the complete source code package for the official repository. Users who have installed the Rust toolchain can install it directly from the source code at cargo install --git https://github.com/rtk-ai/rtk.

There are more options that you don't want to compile: macOS user brew install rtk, Windows user winget install rtk-ai.rtk, Linux and macOS can also be installed to ~/.local/bin with one click using the official install.sh script.

The official Releases page also provides precompiled binaries for Windows, macOS, and Linux. After downloading the Windows version, put rtk.exe into path. Be careful not to double-click in the Explorer.

After the installation is completed, perform rtk --version and rtk gain verification; if you are prompted that the command cannot be found, it means that the installation directory has not been added to path.

Beware of items with the same name: there is another Rustin Type Kit called rtk on crates.io. If rtk gain reports an error, it is likely to be the wrong package.

Officially clarified: the reduction is the bash output, which does not mean that the bill is directly reduced by 90% - the input token also contains system prompts and conversation history, and the output token is completely unaffected. The number it reports is estimated in bytes divided by four, the percentage is reliable, and the absolute value is only approximate. The tool will override your shell command execution path, it is recommended to try it out in a non-core project first. This article is compiled from self-disclosure materials. The resources are for learning and communication only. Please follow the project Apache-2.0 license.