CLI proxy that reduces LLM token consumption by 60-90% on dev commands

RTK, an open-source Rust-based CLI proxy from the rtk-ai project, intercepts shell commands and compresses their output before it reaches an AI coding agent's context, cutting bash output size by up to 90% across 100+ supported commands with under 10ms of overhead. The project states the reduction applies to bash output only — one contributor to input tokens alongside the prompt, system prompt and conversation history — and that its token counts are estimated as bytes divided by 4, so percentages are reliable but absolute token figures are approximate. RTK ships as three downloads: the full `rtk` edition (Apache-2.0 plus BUSL-1.1, with hooks, filters and engine), an Apache-2.0-only `rtk-oss` edition, and `rtk-proxy` (BUSL-1.1) for compressing API traffic; the two `rtk` editions install a binary of the same name and cannot be installed together.

Agent-agnostic token optimization: compress, route, filter, and more. One composable pipeline across everything your AI agent reads and sends — built on RTK's battle-tested bash-output compression up to 90% smaller . Website https://www.rtk-ai.app • Install installation • Troubleshooting https://www.rtk-ai.app/guide/resources/troubleshooting • Architecture https://github.com/rtk-ai/rtk/blob/develop/docs/contributing/ARCHITECTURE.md • Discord https://discord.gg/RySmvNF5kF English https://github.com/rtk-ai/rtk/blob/develop/README.md • Francais https://github.com/rtk-ai/rtk/blob/develop/README fr.md • 中文 https://github.com/rtk-ai/rtk/blob/develop/README zh.md • 日本語 https://github.com/rtk-ai/rtk/blob/develop/README ja.md • 한국어 https://github.com/rtk-ai/rtk/blob/develop/README ko.md • Espanol https://github.com/rtk-ai/rtk/blob/develop/README es.md • Português https://github.com/rtk-ai/rtk/blob/develop/README pt.md rtk filters and compresses command outputs before they reach your LLM context. Single Rust binary, 100+ supported commands, <10ms overhead. Angular builds are supported with rtk ng build : compact build tables with every bundle and diagnostic retained. RTK intercepts shell commands and compresses their output before your agent reads it. | Operation | What RTK does to the output | |---|---| | ls / tree | Tree format with file counts instead of one line per entry | | cat / read | Smart file reading: signatures and structure over full bodies | | grep / rg | Truncates long lines, groups matches by file | | ast-grep | Groups structural matches by file, caps overflow | | git status | Compact stat format, grouped by state | | git diff | Reduced context, headers stripped | | git log | Hash, author and subject only | | git add/commit/push | Confirmation line instead of full progress output | | cargo test / npm test | Failures only, passing tests collapsed to a count | | ruff check | Grouped by rule and file | | sqlfluff lint | Grouped by rule and file | | pytest | Failures only, traceback trimmed | | go test | NDJSON parsed, failures only | | docker ps | Essential fields only | RTK reduces the bash output your agent reads. That is what RTK measures, and it is not the same as cutting your bill by the same amount. Bash output is one contributor to input tokens , alongside your prompt, the system prompt and conversation history. Input tokens are in turn only part of the bill , which also counts output tokens. The reduction dilutes at every step. The token counts RTK reports are estimated as bytes / 4 — RTK ships no tokenizer, so the percentages are reliable but the absolute token numbers are approximate . Full explanation: How RTK Savings Work https://github.com/rtk-ai/rtk/blob/develop/docs/guide/resources/savings-explained.md brew install rtk macOS / Linux winget install rtk-ai.rtk Windows curl -fsSL https://raw.githubusercontent.com/rtk-ai/rtk/refs/heads/master/install.sh | sh Then check you have the right package — another project named "rtk" exists on crates.io: rtk --version any current version rtk gain must show the savings dashboard, not "command not found" Cargo, pre-built binaries, native Windows, WSL, and uninstall: Installation guide https://www.rtk-ai.app/guide/getting-started/installation RTK ships as three downloads. The two rtk editions install a binary with the same name — hooks, scripts and agent config work unchanged across both — so they cannot be installed together. Uninstall one before installing the other. flowchart TD agent "Your coding agent" subgraph editions "Pick one · both install a binary named rtk" direction LR full "<b rtk</b <br/ Apache-2.0 + BUSL-1.1<br/ hooks · filters · engine" oss "<b rtk-oss</b <br/ Apache-2.0 only<br/ hooks · filters" end proxy "<b rtk-proxy</b <br/ BUSL-1.1<br/ compresses API traffic" agent -- |"command output"| full agent -- |"command output"| oss agent -.- |"API traffic"| proxy classDef apache stroke: 2da44e,stroke-width:2px,fill:none classDef busl stroke: 0969da,stroke-width:2px,fill:none classDef mixed stroke: 8250df,stroke-width:2px,fill:none classDef plain stroke: 8c959f,stroke-width:1px,fill:none class full mixed class oss apache class proxy busl class agent plain style editions fill:none,stroke: d0d7de,stroke-dasharray:4 4 | Download | Licence | Contains | |---|---|---| | rtk-<target | Apache-2.0 + BUSL-1.1 | Hook core, every command filter, and the compression engine | | rtk-oss-<target | Apache-2.0 only | Hook core and every command filter. No engine. | | rtk-proxy-<target | BUSL-1.1 | The RTK Proxy daemon. Never bundled with either rtk . | Production use is free , engine and daemon included. What the BUSL grant does not cover is offering RTK or a derivative to third parties as a commercial product or service — for that, contact contact@rtk-ai.app mailto:contact@rtk-ai.app . curl -fsSL .../install.sh | RTK EDITION=oss sh Apache-2.0 edition brew install rtk-ai/tap/rtk-oss What the Apache-2.0 edition omits and where the licence boundary falls: Editions and Licensing https://www.rtk-ai.app/guide/resources/editions 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 --agent kimi Kimi AI rtk init -g --agent pi Pi rtk init --agent omp Oh My Pi OMP rtk init --agent hermes Hermes rtk init -g --agent droid Factory Droid rtk init --agent trae Trae project: .trae/hooks.json rtk init -g --agent trae Trae global: ~/.trae and existing ~/.trae-cn 2. Restart your AI tool, then test git status Automatically rewritten to rtk git status The agent receives compact output without ever calling rtk explicitly. The hook only fires on Bash tool calls. Built-in tools like Read , Grep and Glob do not pass through it. Use shell commands cat , rg , find or call rtk read , rtk grep , rtk find directly. Per-agent setup, --dry-run , and uninstall: Quick Start https://www.rtk-ai.app/guide/getting-started/quick-start · Supported Agents https://www.rtk-ai.app/guide/getting-started/supported-agents Without rtk: With rtk: Claude --git status-- shell -- git Claude --git status-- RTK -- git ^ | ^ | | | full raw output | | compact output | filter | +-----------------------------------+ +------- filtered ---+----------+ Four strategies applied per command type: 1. Smart Filtering - Removes noise comments, whitespace, boilerplate 2. Grouping - Aggregates similar items files by directory, errors by type 3. Truncation - Keeps relevant context, cuts redundancy 4. Deduplication - Collapses repeated log lines with counts Does RTK break Claude's prompt cache? No. RTK filters output once per command. The result is stored in history and cached normally on subsequent API calls, so the cache keeps working as expected. Smaller outputs also mean cheaper cache writes and reads. See Troubleshooting https://github.com/rtk-ai/rtk/blob/develop/docs/guide/resources/troubleshooting.md does-rtk-break-claudes-prompt-cache for details. RTK supports 18 AI coding tools. Each integration rewrites shell commands to rtk equivalents, reducing the bash output the agent reads where the agent supports command interception. | Tool | Install | Method | |---|---|---| | Claude Code | rtk init -g | PreToolUse hook native binary | | 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 | PreToolUse hook updatedInput + AGENTS.md | | 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 execute.before / tool.execute.before , needs 1.18.29 or newer | | OpenClaw | openclaw plugins install ./openclaw | Plugin TS before tool call | | Pi | rtk init -g --agent pi global | TypeScript extension tool call | | Oh My Pi OMP | rtk init -g --agent omp global / rtk init --agent omp project | TypeScript extension tool call, shared with Pi | | Hermes | rtk init --agent hermes | Python plugin adapter terminal command mutation via rtk rewrite | | Mistral Vibe | rtk init -g --agent vibe | pre tool hook hooks.toml | | Kilo Code | rtk init --agent kilocode | .kilocode/rules/rtk-rules.md project-scoped | | Google Antigravity | rtk init --agent antigravity / rtk init -g --agent antigravity | .agents/plugins/rtk/ project or ~/.gemini/config/plugins/rtk/ global : plugin.json, hooks.json, rules/AGENTS.md | | Kimi AI | rtk init --agent kimi | AGENTS.md project-scoped | | Factory Droid | rtk init -g --agent droid or per-project | PreToolUse hook in ~/.factory/hooks.json matcher Execute | | Trae | rtk init --agent trae | Native PreToolUse hook in .trae/hooks.json RunCommand | | Trae global | rtk init -g --agent trae | ~/.trae/hooks.json , plus ~/.trae-cn/hooks.json when that directory exists | For per-agent setup details, override controls, and graceful degradation, see the Supported Agents guide https://www.rtk-ai.app/guide/getting-started/supported-agents . The Hermes plugin source and tests live in hooks/hermes/ ; installed Hermes runtime files still live under ~/.hermes/plugins/rtk-rewrite/ . 100+ commands across Git, GitHub CLI, Cargo/Rust, JavaScript npm, pnpm, vitest, jest, tsc, Next.js, Playwright, Prisma , Python ruff, pytest, mypy, pip , Go go test, golangci-lint , Ruby, .NET, JVM Gradle, Maven , PHP, Docker, Kubernetes, AWS, Terraform, and the file/search builtins. -v, --verbose increase verbosity -v, -vv, -vvv rtk bypass <cmd run one command unfiltered, still tracked Every command and its filter: What RTK Optimizes https://www.rtk-ai.app/guide/resources/what-rtk-covers rtk filters command output by default. When a result looks wrong, bypass the filter for one command to see the raw output and tell a filter bug apart from the real thing: rtk bypass git log --oneline -20 full git log, no truncation rtk bypass npm install express raw npm output, no filtering rtk bypass curl https://api.example.com/data - What it does : runs one command unfiltered and still tracks it — bypassed commands appear in rtk gain --history with 0% bash output reduction. - When to use it : an output looks off and you need to know whether the filter or the command produced it, when debugging a filter, or for an edge case a filter mishandles. - rtk proxy <cmd is a deprecated alias of rtk bypass <cmd . Not the same thing as rtk llm-proxy . rtk bypass runs one local command unfiltered. rtk llm-proxy manages the rtk-proxy daemon, which compresses your agent's provider-API traffic — see RTK Proxy rtk-proxy-optional . rtk 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 Attribution, the live dashboard and export formats: Token Savings Analytics https://www.rtk-ai.app/guide/analytics/gain rtk optimizes command output before your agent reads it. The rtk-proxy daemon extends the same engine to your agent's provider-API traffic — a local background process that sits between your agent and the provider and runs the pipeline on the traffic itself: it compresses payloads, strips bytes no model ever needed before forwarding, and carries the calls your pipeline routes to cheaper models, so they borrow the credential your agent already sends and show up in rtk gain . It can also align prompt-cache breakpoints where the agent leaves them open opt-in . rtk claude start the daemon if needed, then launch Claude through it rtk llm-proxy status is it up rtk gain savings, command-filtering and proxy side by side Two independent ways in , because not every harness has a session hook: | | What it does | |---|---| | rtk init -g | Offers to set it up once: writes the base URL and the rtk:proxy pipeline, then asks how the daemon should come back after a reboot — SessionStart hook, background service, or neither. | | rtk <harness | No configuration at all. Starts the daemon, points the harness at it, then execs it. Needs no hook system, which is why it covers harnesses that have none. | rtk <harness resolving is itself the signal that traffic really goes through the daemon — the subcommand exists only where redirection is verified. Today that is rtk claude . A harness without one is never silently unproxied: it falls through to plain passthrough, and rtk llm-proxy setup lists what can be launched. It is a separate binary under a separate licence BUSL-1.1 , shipped as its own rtk-proxy-<target archive — rtk never links it. Setup and subcommands: RTK Proxy https://www.rtk-ai.app/guide/proxy/overview · what it compresses: What the Proxy Compresses https://www.rtk-ai.app/guide/proxy/compression · settings and endpoints: Proxy Configuration https://www.rtk-ai.app/guide/proxy/configuration Everything RTK does — which commands get rewritten, what happens to a tool's output, what the proxy compresses — is expressed in one composable file. The engine engine/ , crate rtk-engine , BUSL-1.1 reads it, so the levers are configurable instead of hard-coded. Upgrading changes nothing. With no pipeline file you are on rtk:default : the same PreToolUse rewrite, the same awareness file, your filters.toml , your config.toml . Everything beyond that is opt-in, one line at a time: ~/.config/rtk/pipeline.toml pipeline extends = "rtk:posthook", "rtk:proxy" The tour: Pipelines https://www.rtk-ai.app/guide/pipelines/overview · the reference: Writing a Pipeline https://www.rtk-ai.app/guide/pipelines/writing-pipelines , Conditions and Judges https://www.rtk-ai.app/guide/pipelines/conditions , Methods https://www.rtk-ai.app/guide/pipelines/methods , Tasks and Upstreams https://www.rtk-ai.app/guide/pipelines/tasks · the commands: Pipeline Commands https://www.rtk-ai.app/guide/pipelines/commands · write your own method: Plugins https://www.rtk-ai.app/guide/pipelines/plugins rtk-ai.app/guide https://www.rtk-ai.app/guide is the full user guide. | Installation https://www.rtk-ai.app/guide/getting-started/installation | every install method, Windows, WSL, uninstall | | Quick Start https://www.rtk-ai.app/guide/getting-started/quick-start | per-agent init, --dry-run , first savings | | Supported Agents https://www.rtk-ai.app/guide/getting-started/supported-agents | setup detail, override controls, degradation | | Agent Coverage https://www.rtk-ai.app/guide/resources/agent-coverage | what each agent's hook API lets RTK do | | What RTK Optimizes https://www.rtk-ai.app/guide/resources/what-rtk-covers | every command and its filter | | Configuration https://www.rtk-ai.app/guide/getting-started/configuration | config.toml , env vars, recall recovery | | Token Savings Analytics https://www.rtk-ai.app/guide/analytics/gain | rtk gain in full | | Pipelines https://www.rtk-ai.app/guide/pipelines/overview | the engine: pipeline.toml , rules, judges, tasks, sharing | | RTK Proxy https://www.rtk-ai.app/guide/proxy/overview | the daemon: setup, what it compresses, settings | | Editions and Licensing https://www.rtk-ai.app/guide/resources/editions | what each download contains | | Telemetry & Privacy https://www.rtk-ai.app/guide/resources/telemetry | what is collected, how to opt in, your GDPR rights | | Troubleshooting https://www.rtk-ai.app/guide/resources/troubleshooting | common issues, prompt-cache questions | Repository references: engine/README.md https://github.com/rtk-ai/rtk/blob/develop/engine/README.md · proxy/README.md https://github.com/rtk-ai/rtk/blob/develop/proxy/README.md · ARCHITECTURE.md https://github.com/rtk-ai/rtk/blob/develop/docs/contributing/ARCHITECTURE.md · CONTRIBUTING.md https://github.com/rtk-ai/rtk/blob/develop/CONTRIBUTING.md · SECURITY.md https://github.com/rtk-ai/rtk/blob/develop/SECURITY.md RTK collects no command content and no file contents . Telemetry is anonymous and off by default — it sends nothing until you opt in with explicit consent GDPR Art. 6 & 7 via rtk telemetry enable , and documented in Telemetry & Privacy https://www.rtk-ai.app/guide/resources/telemetry . - Patrick Szymkowiak — Founder GitHub https://github.com/pszymkowiak · LinkedIn https://www.linkedin.com/in/patrick-szymkowiak/ - Florian Bruniaux — Core contributor GitHub https://github.com/FlorianBruniaux · LinkedIn https://www.linkedin.com/in/florian-bruniaux-43408b83/ - Adrien Eppling — Core contributor GitHub https://github.com/aeppling · LinkedIn https://www.linkedin.com/in/adrien-eppling/ - Nicolas Le Cam — Core contributor Github https://github.com/kush · LinkedIn https://www.linkedin.com/in/nicolas-le-cam-386387160/ - Takayuki Maeda — Core contributor GitHub https://github.com/TaKO8Ki · LinkedIn https://www.linkedin.com/in/tako8ki/ Contributions welcome Please open an issue or PR on GitHub https://github.com/rtk-ai/rtk . Join the community on Discord https://discord.gg/RySmvNF5kF . The rtk CLI is Apache-2.0 — see LICENSE https://github.com/rtk-ai/rtk/blob/develop/LICENSE . It links one component under a different licence. rtk-engine engine/ is BUSL-1.1 , source-available: see engine/LICENSE https://github.com/rtk-ai/rtk/blob/develop/engine/LICENSE . Its Additional Use Grant permits production use as part of the rtk binary, so running rtk is covered; using the engine on its own, or inside another product, is not until the Change Date. The rtk-proxy daemon proxy/ is BUSL-1.1 on the same terms and ships as its own archive with its licence alongside — rtk never links it. Your company is looking to take control back on your AI fleet ? RTK Pro provides the control layer for costs, security and governances for all agents. Check it out : RTK Pro https://pro.rtk-ai.app . See DISCLAIMER.md https://github.com/rtk-ai/rtk/blob/develop/DISCLAIMER.md .