openrtk

OpenCode plugin for RTK (Rust Token Killer). Reduces LLM token consumption by 60-90% on common dev commands by transparently routing them through RTK's output compression.

A lightweight plugin that intercepts shell commands and pipes them through RTK for automatic output compression. No changes needed to prompts or workflow.

Prerequisites

Install RTK:

brew install rtk
# or
cargo install --git https://github.com/rtk-ai/rtk

Verify: rtk --version should print rtk X.Y.Z.

Installation

Install via npm:

npm install @cafeng/openrtk

Add to your OpenCode config (opencode.json or .opencode/config.json):

{
  "plugins": ["@cafeng/openrtk"]
}

User Guide

How It Works

The plugin hooks into OpenCode's tool.execute.before event. When the AI decides to run a shell command, the plugin intercepts it before execution, asks rtk rewrite whether it can be compressed, and swaps the command in-place. The AI never sees the rewrite — it just gets shorter output.

┌──────────────────────────────────────────────────────┐
│  OpenCode                                            │
│                                                      │
│  AI runs: "git status"                               │
│       │                                              │
│       ▼  tool.execute.before hook fires              │
│  ┌────────────────────────────────────┐              │
│  │  openrtk plugin                    │              │
│  │                                    │              │
│  │  1. tool == "bash"?     ✓          │              │
│  │  2. extract command     "git status"│              │
│  │  3. call rtk rewrite ──────────────┼──► rtk binary│
│  │  4. get back           "rtk git status"           │
│  │  5. swap args.command              │              │
│  │  6. record in tracker              │              │
│  └────────────────────────────────────┘              │
│       │                                              │
│       ▼                                              │
│  Shell runs: rtk git status (compressed output)      │
│       │                                              │
│       ▼                                              │
│  AI sees: ~200 tokens instead of ~2000                │
└──────────────────────────────────────────────────────┘

All rewrite logic lives in rtk rewrite (the Rust binary's single source of truth — 70+ patterns). The plugin is a thin delegate. When new filters are added to RTK, the plugin picks them up automatically with zero code changes.

git status       →  rtk git status       (72% savings)
cargo test       →  rtk cargo test       (90% savings)
docker ps        →  rtk docker ps        (65% savings)

What Gets Rewritten

Any bash/shell command that rtk rewrite recognizes — git, cargo, npm, docker, pytest, go, kubectl, AWS, and many more.

What Does NOT Get Rewritten

OpenCode's built-in tools (Read, Grep, Glob) bypass the bash hook entirely, so they are not rewritten. If you want RTK compression on file operations, use the shell equivalents:

| Built-in Tool (no compression) | Shell Equivalent (with compression) | |-------------------------------|-------------------------------------| | Read tool | cat / rtk read | | Grep tool | rg / rtk grep | | Glob tool | find / rtk find |

Commands already prefixed with rtk are skipped (no double-rewriting). Unrecognized commands pass through unchanged.

Graceful Degradation

The plugin never blocks a command from executing. Every error path falls back to the original command:

| Scenario | Behavior | |----------|----------| | rtk not installed | Plugin silently disables itself | | rtk rewrite crashes | Original command runs unchanged | | rtk rewrite times out (2s) | Original command runs unchanged | | Command already has rtk prefix | Skipped, no double-rewrite | | Command not in rtk registry | Passes through unchanged |

Session Tracking

The plugin counts how many commands were rewritten during each OpenCode session:

[rtk] Session: 15 commands rewritten.
  git status → rtk git status
  cargo test → rtk cargo test
  docker ps → rtk docker ps
Run `rtk gain` for detailed token savings.

Meta Commands

These RTK commands are useful for checking your savings:

rtk gain              # Token savings dashboard
rtk gain --history    # Per-command history with savings breakdown
rtk gain --graph      # ASCII graph (last 30 days)
rtk discover          # Find commands you forgot to optimize
rtk session           # RTK adoption across recent sessions
rtk proxy <cmd>       # Run a command raw (no filtering, for debugging)

Supported Commands

| Category | Commands | |----------|----------| | Git | status, diff, log, add, commit, push, pull, branch, fetch, stash, show | | GitHub CLI | pr, issue, run, api, release | | Rust | cargo test/build/clippy/check/install/fmt | | File ops | cat (→ rtk read), grep/rg (→ rtk grep), ls, tree, find | | JS/TS | vitest, npm test/run, tsc, eslint, prettier, playwright, prisma | | Containers | docker (ps/images/logs/compose), kubectl (pods/logs/services) | | Python | pytest, ruff, pip | | Go | go test/build/vet, golangci-lint | | AWS | sts, ec2, lambda, s3, cloudformation, dynamodb, logs, iam | | Network | curl, wget |

Development

bun test     # run tests

License

MIT