setup-rtk

name	setup-rtk
description	Install and configure RTK (Rust Token Killer) for CLI output compression. Opt-in utility — detects OS, downloads binary, adds to PATH, runs rtk init -g. Invoke with /setup-rtk.

Setup RTK (Rust Token Killer)

Optional utility to install RTK — a CLI proxy that compresses Bash command output before it enters the context window. Reduces token consumption by 50-80% on common commands (git, ls, npm, etc.).

This is opt-in. RTK is not required for Crabshell to function. Users invoke /setup-rtk only when they want CLI output compression.

Steps

Step 1: Check if RTK is already installed

Run: which rtk 2>/dev/null || where rtk 2>/dev/null

• If found → report version (rtk --version) and skip to Step 5
• If not found → proceed to Step 2

Step 2: Detect OS and architecture

OS=$(uname -s 2>/dev/null || echo "Windows")
ARCH=$(uname -m 2>/dev/null || echo "x86_64")

Map to RTK release asset name:

OS	Arch	Asset
Linux	x86_64	rtk-x86_64-unknown-linux-gnu.tar.gz
Linux	aarch64	rtk-aarch64-unknown-linux-gnu.tar.gz
Darwin	x86_64	rtk-x86_64-apple-darwin.tar.gz
Darwin	arm64	rtk-aarch64-apple-darwin.tar.gz
Windows / MINGW / MSYS	x86_64	rtk-x86_64-pc-windows-msvc.zip

If OS/arch combination is not in the table → report and stop.

Step 3: Download and extract

# Create install directory
mkdir -p "$HOME/tools/rtk"

# Download from GitHub releases (latest)
curl -sL "https://github.com/rtk-ai/rtk/releases/latest/download/{ASSET}" -o /tmp/rtk-download

# Extract
# For .tar.gz: tar -xzf /tmp/rtk-download -C "$HOME/tools/rtk/"
# For .zip: unzip -o /tmp/rtk-download -d "$HOME/tools/rtk/"

# Verify
"$HOME/tools/rtk/rtk" --version  # or rtk.exe on Windows

Step 4: Add to PATH

Detect shell config file:

• If $SHELL contains zsh → ~/.zshrc
• If $SHELL contains bash → ~/.bashrc
• Windows Git Bash → ~/.bashrc

Check if already in PATH config:

grep -q 'tools/rtk' "$SHELL_CONFIG" 2>/dev/null

• If already present → skip
• If not → append: export PATH="$HOME/tools/rtk:$PATH"

Step 5: Initialize RTK for Claude Code

rtk init -g

This adds RTK usage instructions to ~/.claude/CLAUDE.md. On Windows, this uses --claude-md mode (text instructions) instead of hook mode.

Step 6: Report

Tell user:

RTK installed:
- Binary: ~/tools/rtk/rtk (or rtk.exe)
- Version: {version}
- PATH: added to {shell config file}
- Claude Code: ~/.claude/CLAUDE.md updated with RTK instructions
- Mode: {hook (Unix) or claude-md (Windows)}

Next session will automatically use RTK for Bash commands.
To verify: run `rtk --version` in a new terminal.
To uninstall: delete ~/tools/rtk/ and remove the PATH line from {shell config}.

Notes

• RTK is a third-party tool (github.com/rtk-ai/rtk), not part of Crabshell
• On Windows, RTK operates via CLAUDE.md text instructions (model must prefix commands with rtk), not hooks
• On Unix (Mac/Linux), RTK can use PreToolUse hooks for automatic interception
• RTK only affects Bash tool output — does not touch Read/Edit/Write/Grep tools or memory pipeline
• If download fails (network issues, GitHub rate limit), report error and stop — do not retry