RTK Plugin for Hermes

Transparently rewrites shell commands executed via Hermes's terminal tool to their RTK equivalents, achieving 60-90% LLM token savings.

Installation

# 1. Install RTK
brew install rtk
# or: curl -fsSL https://raw.githubusercontent.com/rtk-ai/rtk/refs/heads/master/install.sh | sh

# 2. Install the plugin
pip install rtk-hermes

# 3. Restart Hermes — the plugin auto-registers, no config needed

How it works

Agent runs: terminal(command="cargo test --nocapture")
  → Plugin intercepts pre_tool_call hook
  → Calls `rtk rewrite "cargo test --nocapture"`
  → Mutates args["command"] = "rtk cargo test --nocapture"
  → Agent executes the rewritten command
  → Filtered output reaches LLM (~90% fewer tokens)

The plugin registers a pre_tool_call hook that intercepts terminal tool calls. When the agent runs a command like git status, the plugin delegates to rtk rewrite which returns the optimized command (e.g. rtk git status). The compressed output enters the agent's context window, saving tokens.

All rewrite logic lives in RTK itself (rtk rewrite). This plugin is a thin delegate — when new filters are added to RTK, the plugin picks them up automatically with zero changes.

What gets rewritten

Everything that rtk rewrite supports (30+ commands): git, grep, find, ls, cargo, pytest, npm, docker, kubectl, and more. See the full command list.

Measured savings

Command	Token savings
cargo test	90-99%
git log --stat	87%
ls -la	78%
git status	66%
grep (single file)	52%

Configuration

The plugin is enabled by default when RTK is found in $PATH. To disable:

# ~/.hermes/config.yaml
plugins:
  disabled:
    - rtk-rewrite

Graceful degradation

The plugin never blocks command execution:

• RTK binary not found → plugin disabled silently
• rtk rewrite times out (>2s) → command passes through unchanged
• rtk rewrite crashes → command passes through unchanged
• No RTK equivalent → command passes through unchanged

License

MIT — same as RTK.