rtk-output-filtering

model_tier: medium name: rtk-output-filtering description: "Use when running verbose CLI commands — wraps them with rtk (Rust Token Killer) for 60-90% token savings. Covers installation, configuration, and usage patterns." domain: process execution: type: assisted handler: shell allowed_tools: [] workspaces: - agent-config-maintainer packs: - meta

rtk (Rust Token Killer)

When to use

• Before running any CLI command expected to produce >30 lines of output
• When setting up rtk on a new machine or project
• When creating/optimizing project-local rtk filters

What

High-performance CLI proxy that reduces LLM token consumption by 60-90% on common dev commands through intelligent output filtering (whitespace, boilerplate, comments, duplicate log messages). Single Rust binary, <10ms startup overhead.

Docs: https://www.mintlify.com/rtk-ai/rtk Repo: https://github.com/rtk-ai/rtk

Usage

Wrap any CLI command with rtk:

rtk git status        # 80-92% savings
rtk git log           # compact log output
rtk cargo test        # 90% savings — only failures shown
rtk npm test          # same for JS/TS
rtk docker compose ps # compact container status

Procedure: Analyze, then wrap commands with rtk

1. Analyze the current setup

• Read personal.rtk_installed from .agent-settings.yml.
• Review the command about to run: estimated output size, whether completeness matters (e.g. diff review), and whether a project-local filter exists in .rtk/filters.toml.

2. Wrap (or skip)

1. If personal.rtk_installed: true → prefix commands with rtk when output >30 lines expected.
2. If false or missing → use plain commands. Do not prompt the user.
3. After wrapping: verify output is useful (not truncated on completeness-critical commands).

Installation and one-time setup are owned by /onboard. If the user asks to install rtk outside onboarding, follow the Installation section below and set personal.rtk_installed: true on success.

Output format

1. Wrapped command with rtk prefix
2. Token savings estimate (if first use in conversation)

Installation (on-demand)

Invoked by /onboard when rtk is not on PATH, or on explicit user request. Never fire unsolicited.

1. Ask which installer to use (macOS → Homebrew; otherwise Cargo).
2. Run the installer. On success:
   1. rtk --version to verify.
   2. rtk init --global to enable auto-rewrite hooks.
   3. Apply Post-Install Setup below (telemetry, tee, audit logging).
   4. Generate project-local filters (see Post-Install Setup).
   5. Write personal.rtk_installed: true to .agent-settings.yml.

Post-Install Setup (mandatory)

After installation, always apply these steps before any rtk usage:

1. Disable telemetry

rtk ships with telemetry enabled by default (opt-out). Sends anonymous usage data daily.

# Add BOTH — env var (immediate) + config (persistent)
echo 'export RTK_TELEMETRY_DISABLED=1' >> ~/.zshrc

mkdir -p ~/.config/rtk
# In ~/.config/rtk/config.toml:
# [telemetry]
# enabled = false

2. Enable tee recovery (safety net)

Saves raw unfiltered output on command failures. Auto-cleans (max 20 files, oldest deleted). Prevents re-running commands just to see full output.

# In ~/.config/rtk/config.toml:
[tee]
enabled = true
mode = "failures"
max_files = 20
max_file_size = 1048576

3. Enable hook audit logging

Logs all hook-rewritten commands so you can trace what rtk intercepted.

echo 'export RTK_HOOK_AUDIT=1' >> ~/.zshrc

Reference config (~/.config/rtk/config.toml)

[telemetry]
enabled = false

[tracking]
enabled = true
history_days = 30

[tee]
enabled = true
mode = "failures"
max_files = 20
max_file_size = 1048576

[display]
colors = true
emoji = true
max_width = 120

When to use rtk

Never use rtk for

When debugging or reviewing diffs, always run the raw command without rtk.

Project-Local Filters

Project-local custom filters live in .rtk/filters.toml (project root, versioned in Git). These override global filters for matching commands. Add entries for whatever tools the project actually runs.

Coverage shipped with this package (extend per project):

• PHP / Laravel: PHPStan, Pest, PHPUnit, ECS, Rector, Composer, Artisan
• JS / TS: tsc, eslint, prettier, vitest, jest, playwright, pnpm/npm/yarn install + run
• Python: ruff, mypy, pyright, pytest, pip / poetry / uv
• Go: go test, go build, go vet, golangci-lint
• Rust: cargo build, cargo test, cargo clippy, cargo fmt
• Infra / runtime: Docker Compose, Terraform, kubectl

To generate or update project-local filters → use the /optimize-rtk-filters command.

Gotcha

• rtk git diff silently truncates at ~50 changes — you'll make decisions on incomplete data
• rtk read has the same truncation risk — always use cat/view instead
• Telemetry is enabled by default — always disable it during installation
• The tee recovery (mode = "failures") is your safety net — without it, re-run is the only option

Do NOT

• Do NOT use rtk for git diff or any command where completeness matters
• Do NOT skip the post-install setup (telemetry, tee, audit logging)
• Do NOT use rtk for commands already piped through grep/tail
• Do NOT use rtk for short commands (< 5 lines expected output)