---
name: rtk
description: "Instructions for the upstream workflow: Compact command output before it reaches the model — prefix a shell command with the wrapper and it returns a filtered, smaller form (test failures only, build errors grouped, compact diff, compact status), with meta commands for savings statistics, missed-usages discovery and an unfiltered proxy mode. Use on the verbose and repetitive commands: tests, builds, git, package managers, containers and file listings. Not for compressing model input in general — use universal-compressor; not for the per-turn compression policy — use token-shaper."
license: MIT
metadata:
  version: "1.0.0"
  domain: agent-skills
  canonical-name: rtk
---
# RTK — compact shell output

## Package scope and prerequisites

This catalog ships instructions, not the executable runtime. Python modules, scripts, local services and optional tools named below must be installed separately from the upstream project. Check their availability before running commands; if they are missing, explain the prerequisite instead of claiming execution or results. The host agent may use model tokens while following these instructions.

> A terminal wrapper that compacts command output to cut token usage.

## Purpose

Prefix a command with the wrapper; if it has a dedicated filter the output is
compacted, otherwise it passes through unchanged. Categories with the largest
savings are tests, builds, package managers, containers and git.

    rtk <command>            # filtered output
    rtk gain                 # savings statistics
    rtk discover             # find missed usages in past sessions
    rtk proxy <command>      # run WITHOUT filtering (debugging)
    rtk --version

## Provenance and boundaries

- Upstream is an external project; this repository pins and reviews a specific
  stable version. Check the local version and keep it current — the tool ships
  fixes frequently, including Windows shell detection and exit-code visibility.
- Filtering can hide detail. Use proxy mode whenever the compacted view is not
  enough to understand a failure.
- Known local limitation on Windows: some builtins are not wrapped, so reading a
  file directly through it fails; use proxy mode for those.

The full command table belongs to the separately installed RTK CLI and is not bundled here. Inspect that version's help and upstream documentation before using commands outside this summary.

## When NOT to use

- You want model input compressed rather than shell output — use universal_compressor.
- You want the per-turn compression decision — use token_shaper.