RTK — Rust Token Killer

RTK is natively bundled into OpenCrabs as a built-in feature. It intercepts bash commands before they run, filters and compresses their output, and returns a token-optimized version to the LLM context. The result: 60-90% token savings on common development commands, which directly translates to lower API costs and faster responses.

What It Does

When OpenCrabs runs a bash command like git status or cargo build, RTK:

Intercepts the command before execution
Runs it through RTK’s filtering engine
Compresses verbose output (removes noise, keeps signal)
Returns the optimized output to the agent

The agent sees the same information, but using a fraction of the tokens.

Real-World Impact

From production usage (13,600+ commands executed):

Metric	Value
Total Commands	13,600+
Input Tokens	245M
Output Tokens	35M
Tokens Saved	209M
Savings Rate	85.6%
Total Exec Time	40h 50m (avg 10.8s per command)

Top Commands by Savings

Command	Count	Tokens Saved	Avg Savings
`rtk grep`	1,920	175M	16.3%
`rtk find`	1,670	24M	71.1%
`rtk cargo test --all-...`	90	5.4M	99.8%
`rtk cargo test`	40	2.1M	100.0%
`rtk:toml ps aux`	30	1.2M	97.9%

Supported Commands

RTK supports 40+ common development and sysadmin commands:

Version Control

git, gh (GitHub CLI), glab (GitLab CLI)

Package Managers

npm, npx, pnpm, cargo, dotnet

Build & Test

jest, vitest, tsc, next, prisma, prettier, eslint, playwright

Cloud & Infrastructure

aws, docker, kubectl, psql

System Inspection (Sysadmin)

ps, top, lsof, netstat, ss, journalctl, dmesg, dig, nslookup, host, traceroute

File Operations

grep, find, ls, tree, diff, curl, wget

Blocked Commands

RTK never rewrites these (too interactive, security-sensitive, or already RTK meta-commands):

sudo, ssh, scp, sftp, rsync, vim, vi, nvim, nano, emacs, less, more, man, python, python3, node, mysql, redis-cli, psql

How It Works

Command Rewriting

When the agent runs git status, OpenCrabs automatically rewrites it to rtk git status. RTK then:

Executes git status internally
Parses the output structure
Applies command-specific filters (e.g., for git diff: show file names and change stats, not full diffs)
Returns the compressed output

Smart Filtering

RTK uses different strategies per command:

Git commands: Show file-level summaries, not full diffs
Cargo build/test: Show errors and warnings, skip successful compilations
System commands (ps, top): Use TOML filter templates to extract key metrics
File searches (grep, find): Limit output length, show context only when relevant

/rtk Command

In the TUI, type /rtk to see your token savings dashboard:

═══ RTK Token Savings Report ═══

Total Commands: 13,600+
Total Tokens Saved: 209M
Average Savings: 85.6%
Tracking Since: 2026-05-15 10:30:00 UTC

Savings by Command Type:
  grep: 1,920 cmds, 175M tokens saved, 16.3% avg
  find: 1,670 cmds, 24M tokens saved, 71.1% avg
  cargo: 130 cmds, 7.5M tokens saved, 99.9% avg
  ...

Installation

RTK is enabled by default in all OpenCrabs builds. No setup required.

If you’re building from source and want to disable it:

cargo build --no-default-features --features telegram,whatsapp,discord,slack,trello,local-stt,local-tts,browser

To verify RTK is active:

# In the TUI, type:
/rtk

# Or check if the binary is available:
which rtk

Why It Matters

LLM API costs are based on token count. A typical git diff on a large repo can produce 50,000+ tokens of output. With RTK, that same diff might use only 5,000 tokens — a 90% reduction.

Over a day of heavy development work:

Without RTK: ~250M tokens consumed by command outputs
With RTK: ~35M tokens consumed
Savings: ~215M tokens per day

At typical API pricing ($3-15 per 1M input tokens), that’s $600-3,000+ saved per day in token costs alone.

Learn More

RTK source: github.com/rtk-ai/rtk
RTK is developed by fast-rlm and integrated natively into OpenCrabs

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