Rtk
CLI proxy that reduces LLM token consumption by 60-90% on common dev commands. Single Rust binary, zero dependencies
High-performance CLI proxy that reduces LLM token consumption by 60-90% The project is written primarily in Rust, distributed under the Apache License 2.0 license, first published in 2026. It has gained significant community traction with 62,583 stars and 3,871 forks on GitHub. Key topics include: agentic-coding, ai-coding, anthropic, claude-code, cli.
rtk filters and compresses command outputs before they reach your LLM context. Single Rust binary, 100+ supported commands, <10ms overhead.
Token Savings (30-min Claude Code Session)
| Operation | Frequency | Standard | rtk | Savings |
|---|---|---|---|---|
ls / tree | 10x | 2,000 | 400 | -80% |
cat / read | 20x | 40,000 | 12,000 | -70% |
grep / rg | 8x | 16,000 | 3,200 | -80% |
git status | 10x | 3,000 | 600 | -80% |
git diff | 5x | 10,000 | 2,500 | -75% |
git log | 5x | 2,500 | 500 | -80% |
git add/commit/push | 8x | 1,600 | 120 | -92% |
cargo test / npm test | 5x | 25,000 | 2,500 | -90% |
ruff check | 3x | 3,000 | 600 | -80% |
pytest | 4x | 8,000 | 800 | -90% |
go test | 3x | 6,000 | 600 | -90% |
docker ps | 3x | 900 | 180 | -80% |
| Total | ~118,000 | ~23,900 | -80% |
Estimates based on medium-sized TypeScript/Rust projects. Actual savings vary by project size.
Installation
Homebrew (recommended)
bashbrew install rtk
Quick Install (Linux/macOS)
bashcurl -fsSL https://raw.githubusercontent.com/rtk-ai/rtk/refs/heads/master/install.sh | sh
Installs to
~/.local/bin. Add to PATH if needed:bashecho 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc # or ~/.zshrc
Cargo
bashcargo install --git https://github.com/rtk-ai/rtk
Pre-built Binaries
Download from releases:
- macOS:
rtk-x86_64-apple-darwin.tar.gz/rtk-aarch64-apple-darwin.tar.gz - Linux:
rtk-x86_64-unknown-linux-musl.tar.gz/rtk-aarch64-unknown-linux-gnu.tar.gz - Windows:
rtk-x86_64-pc-windows-msvc.zip
Windows users: Extract the zip and place
rtk.exesomewhere in your PATH (e.g.C:\Users\<you>\.local\bin). Run RTK from Command Prompt, PowerShell, or Windows Terminal — do not double-click the.exe(it will flash and close). For the best experience, use WSL where the full hook system works natively. See Windows setup below for details.
Verify Installation
bashrtk --version # Should show "rtk 0.28.2" rtk gain # Should show token savings stats
Name collision warning: Another project named "rtk" (Rust Type Kit) exists on crates.io. If
rtk gainfails, you have the wrong package. Usecargo install --gitabove instead.
Quick Start
bash# 1. Install for your AI tool rtk init -g # Claude Code / Copilot (default) rtk init -g --gemini # Gemini CLI rtk init -g --codex # Codex (OpenAI) rtk init -g --agent cursor # Cursor rtk init -g --agent windsurf # Windsurf rtk init --agent cline # Cline / Roo Code rtk init --agent kilocode # Kilo Code rtk init --agent antigravity # Google Antigravity rtk init -g --agent pi # Pi rtk init --agent hermes # Hermes # 2. Restart your AI tool, then test git status # Automatically rewritten to rtk git status
Hook-based agents rewrite Bash commands (e.g., git status -> rtk git status) before execution. Plugin-based agents, including Hermes, use their plugin API to rewrite commands before execution. The agent receives compact output without needing to call rtk explicitly.
Important: the hook only runs on Bash tool calls. Claude Code built-in tools like Read, Grep, and Glob do not pass through the Bash hook, so they are not auto-rewritten. To get RTK's compact output for those workflows, use shell commands (cat/head/tail, rg/grep, find) or call rtk read, rtk grep, or rtk find directly.
How It Works
Without rtk: With rtk:
Claude --git status--> shell --> git Claude --git status--> RTK --> git
^ | ^ | |
| ~2,000 tokens (raw) | | ~200 tokens | filter |
+-----------------------------------+ +------- (filtered) ---+----------+
Four strategies applied per command type:
- Smart Filtering - Removes noise (comments, whitespace, boilerplate)
- Grouping - Aggregates similar items (files by directory, errors by type)
- Truncation - Keeps relevant context, cuts redundancy
- Deduplication - Collapses repeated log lines with counts
Commands
Files
bashrtk ls . # Token-optimized directory tree rtk read file.rs # Smart file reading rtk read file.rs -l aggressive # Signatures only (strips bodies) rtk smart file.rs # 2-line heuristic code summary rtk find "*.rs" . # Compact find results rtk grep "pattern" . # Grouped search results rtk diff file1 file2 # Condensed diff
Git
bashrtk git status # Compact status rtk git log -n 10 # One-line commits rtk git diff # Condensed diff rtk git add # -> "ok" rtk git commit -m "msg" # -> "ok abc1234" rtk git push # -> "ok main" rtk git pull # -> "ok 3 files +10 -2"
GitHub CLI
bashrtk gh pr list # Compact PR listing rtk gh pr view 42 # PR details + checks rtk gh issue list # Compact issue listing rtk gh run list # Workflow run status
Test Runners
bashrtk jest # Jest compact (failures only) rtk vitest # Vitest compact (failures only) rtk playwright test # E2E results (failures only) rtk pytest # Python tests (-90%) rtk go test # Go tests (NDJSON, -90%) rtk cargo test # Cargo tests (-90%) rtk rake test # Ruby minitest (-90%) rtk rspec # RSpec tests (JSON, -60%+) rtk err <cmd> # Filter errors only from any command rtk test <cmd> # Generic test wrapper - failures only (-90%)
Build & Lint
bashrtk lint # ESLint grouped by rule/file rtk lint biome # Supports other linters rtk tsc # TypeScript errors grouped by file rtk next build # Next.js build compact rtk prettier --check . # Files needing formatting rtk cargo build # Cargo build (-80%) rtk cargo clippy # Cargo clippy (-80%) rtk ruff check # Python linting (JSON, -80%) rtk golangci-lint run # Go linting (JSON, -85%) rtk rubocop # Ruby linting (JSON, -60%+)
Package Managers
bashrtk pnpm list # Compact dependency tree rtk pip list # Python packages (auto-detect uv) rtk pip outdated # Outdated packages rtk bundle install # Ruby gems (strip Using lines) rtk prisma generate # Schema generation (no ASCII art)
AWS
bashrtk aws sts get-caller-identity # One-line identity rtk aws ec2 describe-instances # Compact instance list rtk aws lambda list-functions # Name/runtime/memory (strips secrets) rtk aws logs get-log-events # Timestamped messages only rtk aws cloudformation describe-stack-events # Failures first rtk aws dynamodb scan # Unwraps type annotations rtk aws iam list-roles # Strips policy documents rtk aws s3 ls # Truncated with tee recovery
Containers
bashrtk docker ps # Compact container list rtk docker images # Compact image list rtk docker logs <container> # Deduplicated logs rtk docker compose ps # Compose services rtk kubectl pods # Compact pod list rtk kubectl logs <pod> # Deduplicated logs rtk kubectl services # Compact service list
Data & Analytics
bashrtk json config.json # Structure without values rtk deps # Dependencies summary rtk env -f AWS # Filtered env vars rtk log app.log # Deduplicated logs rtk curl <url> # Truncate + save full output rtk wget <url> # Download, strip progress bars rtk summary <long command> # Heuristic summary rtk proxy <command> # Raw passthrough + tracking
Token Savings Analytics
bashrtk gain # Summary stats rtk gain --graph # ASCII graph (last 30 days) rtk gain --history # Recent command history rtk gain --daily # Day-by-day breakdown rtk gain --all --format json # JSON export for dashboards rtk discover # Find missed savings opportunities rtk discover --all --since 7 # All projects, last 7 days rtk session # Show RTK adoption across recent sessions
Global Flags
bash-u, --ultra-compact # ASCII icons, inline format (extra token savings) -v, --verbose # Increase verbosity (-v, -vv, -vvv)
Examples
Directory listing:
# ls -la (45 lines, ~800 tokens) # rtk ls (12 lines, ~150 tokens)
drwxr-xr-x 15 user staff 480 ... my-project/
-rw-r--r-- 1 user staff 1234 ... +-- src/ (8 files)
... | +-- main.rs
+-- Cargo.toml
Git operations:
# git push (15 lines, ~200 tokens) # rtk git push (1 line, ~10 tokens)
Enumerating objects: 5, done. ok main
Counting objects: 100% (5/5), done.
Delta compression using up to 8 threads
...
Test output:
# cargo test (200+ lines on failure) # rtk test cargo test (~20 lines)
running 15 tests FAILED: 2/15 tests
test utils::test_parse ... ok test_edge_case: assertion failed
test utils::test_format ... ok test_overflow: panic at utils.rs:18
...
Auto-Rewrite Hook
The most effective way to use rtk. The hook transparently intercepts Bash commands and rewrites them to rtk equivalents before execution.
Result: 100% rtk adoption across all conversations and subagents, zero token overhead.
Scope note: this only applies to Bash tool calls. Claude Code built-in tools such as Read, Grep, and Glob bypass the hook, so use shell commands or explicit rtk commands when you want RTK filtering there.
Setup
bashrtk init -g # Install hook + RTK.md (recommended) rtk init -g --opencode # OpenCode plugin (instead of Claude Code) rtk init -g --auto-patch # Non-interactive (CI/CD) rtk init -g --hook-only # Hook only, no RTK.md rtk init --show # Verify installation
After install, restart Claude Code.
Windows
RTK works on Windows with some limitations. The auto-rewrite hook (rtk-rewrite.sh) requires a Unix shell, so on native Windows RTK falls back to CLAUDE.md injection mode — your AI assistant receives RTK instructions but commands are not rewritten automatically.
Recommended: WSL (full support)
For the best experience, use WSL (Windows Subsystem for Linux). Inside WSL, RTK works exactly like Linux — full hook support, auto-rewrite, everything:
bash# Inside WSL curl -fsSL https://raw.githubusercontent.com/rtk-ai/rtk/refs/heads/master/install.sh | sh rtk init -g
Native Windows (limited support)
On native Windows (cmd.exe / PowerShell), RTK filters work but the hook does not auto-rewrite commands:
powershell# 1. Download and extract rtk-x86_64-pc-windows-msvc.zip from releases # 2. Add rtk.exe to your PATH # 3. Initialize (falls back to CLAUDE.md injection) rtk init -g # 4. Use rtk explicitly rtk cargo test rtk git status
Important: Do not double-click rtk.exe — it is a CLI tool that prints usage and exits immediately. Always run it from a terminal (Command Prompt, PowerShell, or Windows Terminal).
| Feature | WSL | Native Windows |
|---|---|---|
| Filters (cargo, git, etc.) | Full | Full |
| Auto-rewrite hook | Yes | No (CLAUDE.md fallback) |
rtk init -g | Hook mode | CLAUDE.md mode |
rtk gain / analytics | Full | Full |
Supported AI Tools
RTK supports 14 AI coding tools. Each integration rewrites shell commands to rtk equivalents for 60-90% token savings where the agent supports command interception.
| Tool | Install | Method |
|---|---|---|
| Claude Code | rtk init -g | PreToolUse hook (bash) |
| GitHub Copilot (VS Code) | rtk init -g --copilot | PreToolUse hook — transparent rewrite |
| GitHub Copilot CLI | rtk init -g --copilot | PreToolUse deny-with-suggestion (CLI limitation) |
| Cursor | rtk init -g --agent cursor | preToolUse hook (hooks.json) |
| Gemini CLI | rtk init -g --gemini | BeforeTool hook |
| Codex | rtk init -g --codex | AGENTS.md + RTK.md instructions |
| Windsurf | rtk init -g --agent windsurf | .windsurfrules (project-scoped) |
| Cline / Roo Code | rtk init --agent cline | .clinerules (project-scoped) |
| OpenCode | rtk init -g --opencode | Plugin TS (tool.execute.before) |
| OpenClaw | openclaw plugins install ./openclaw | Plugin TS (before_tool_call) |
| Pi | rtk init -g --agent pi (global) | TypeScript extension (tool_call) |
| Hermes | rtk init --agent hermes | Python plugin adapter (terminal command mutation via rtk rewrite) |
| Mistral Vibe | Planned (#800) | Blocked on upstream |
| Kilo Code | rtk init --agent kilocode | .kilocode/rules/rtk-rules.md (project-scoped) |
| Google Antigravity | rtk init --agent antigravity | .agents/rules/antigravity-rtk-rules.md (project-scoped) |
For per-agent setup details, override controls, and graceful degradation, see the Supported Agents guide. The Hermes plugin source and tests live in hooks/hermes/; installed Hermes runtime files still live under ~/.hermes/plugins/rtk-rewrite/.
Configuration
~/.config/rtk/config.toml (macOS: ~/Library/Application Support/rtk/config.toml):
toml[hooks] exclude_commands = ["curl", "playwright"] # skip rewrite for these [tee] enabled = true # save raw output on failure (default: true) mode = "failures" # "failures", "always", or "never"
When a command fails, RTK saves the full unfiltered output so the LLM can read it without re-executing:
FAILED: 2/15 tests
[full output: ~/.local/share/rtk/tee/1707753600_cargo_test.log]
For the full config reference (all sections, env vars, per-project filters), see the Configuration guide.
Uninstall
bashrtk init -g --uninstall # Remove hook, RTK.md, settings.json entry cargo uninstall rtk # Remove binary brew uninstall rtk # If installed via Homebrew
Documentation
- rtk-ai.app/guide — full user guide (installation, supported agents, what gets optimized, analytics, configuration, troubleshooting)
- INSTALL.md — detailed installation reference
- ARCHITECTURE.md — system design and technical decisions
- CONTRIBUTING.md — contribution guide
- SECURITY.md — security policy
Privacy & Telemetry
RTK can collect anonymous, aggregate usage metrics once per day. Telemetry is disabled by default and requires explicit opt-in consent (GDPR Art. 6, 7) during rtk init or via rtk telemetry enable. This data helps us build a better product: identifying which commands need filters, which filters need improvement, and how much value RTK delivers. For the full list of fields, data handling, and contributor guidelines, see docs/TELEMETRY.md.
What is collected and why:
| Category | Data | Why |
|---|---|---|
| Identity | Salted device hash (SHA-256, not reversible) | Count unique installations without tracking individuals |
| Environment | RTK version, OS, architecture, install method | Know which platforms to support and test |
| Usage volume | Command count (24h), total commands, tokens saved (24h/30d/total) | Measure adoption and value delivered |
| Quality | Top 5 passthrough commands (0% savings), parse failure count, commands with <30% savings | Identify missing filters and weak ones to improve |
| Ecosystem | Command category distribution (e.g. git 45%, cargo 20%, js 15%) | Prioritize filter development for popular ecosystems |
| Retention | Days since first use, active days in last 30 | Understand engagement and detect churn |
| Adoption | AI agent hook type (claude/gemini/codex), custom TOML filter count | Track integration coverage and DSL adoption |
| Configuration | Whether config.toml exists, number of excluded commands, project count | Understand user maturity and customization patterns |
| Features | Usage counts for meta-commands (gain, discover, proxy, verify) | Know which RTK features are valued vs unused |
| Economics | Estimated USD savings (based on API token pricing) | Quantify the value RTK provides to users |
All data is aggregate counts or anonymized command names (first 3 words, no arguments). Top commands report only tool names (e.g. "git", "cargo"), never full command lines.
What is NOT collected: source code, file paths, command arguments, secrets, environment variables, personal data, or repository contents.
Manage telemetry:
bashrtk telemetry status # Check current consent state rtk telemetry enable # Give consent (interactive prompt) rtk telemetry disable # Withdraw consent — stops all collection immediately rtk telemetry forget # Withdraw consent + delete all local data + request server-side erasure
Override via environment:
bashexport RTK_TELEMETRY_DISABLED=1 # Blocks telemetry regardless of consent
Star History
<a href="https://www.star-history.com/?repos=rtk-ai%2Frtk&type=date&legend=top-left"> <picture> <source media="(prefers-color-scheme: dark)" srcset="https://api.star-history.com/chart?repos=rtk-ai/rtk&type=date&theme=dark&legend=top-left" /> <source media="(prefers-color-scheme: light)" srcset="https://api.star-history.com/chart?repos=rtk-ai/rtk&type=date&legend=top-left" /> <img alt="Star History Chart" src="https://api.star-history.com/chart?repos=rtk-ai/rtk&type=date&legend=top-left" /> </picture> </a>StarMapper
<a href="https://starmapper.bruniaux.com/rtk-ai/rtk"> <picture> <source media="(prefers-color-scheme: dark)" srcset="https://starmapper.bruniaux.com/api/map-image/rtk-ai/rtk?theme=dark" /> <source media="(prefers-color-scheme: light)" srcset="https://starmapper.bruniaux.com/api/map-image/rtk-ai/rtk?theme=light" /> <img alt="StarMapper" src="https://starmapper.bruniaux.com/api/map-image/rtk-ai/rtk" /> </picture> </a>Core team
- Patrick Szymkowiak — Founder
GitHub · LinkedIn - Florian Bruniaux — Core contributor
GitHub · LinkedIn - Adrien Eppling — Core contributor
GitHub · LinkedIn
Contributing
Contributions welcome! Please open an issue or PR on GitHub.
Join the community on Discord.
License
Apache License 2.0 - see LICENSE for details.
Disclaimer
See DISCLAIMER.md.
Contributors
Showing top 12 contributors by commit count.
