add-rtk

Install rtk — a CLI proxy delivering 60–90% token savings on common dev commands (git, cargo, pytest, docker, kubectl, etc.) — and wire it transparently into agent containers via the Claude Code PreToolUse hook.

What this sets up

• rtk binary at ~/.local/bin/rtk on the host
• ~/.local/bin/rtk mounted read-only at /usr/local/bin/rtk inside the target agent group's containers
• PreToolUse hook in the agent group's settings.json so every Bash call is automatically filtered through rtk — no CLAUDE.md instructions needed

Step 1 — Install rtk on the host

curl -fsSL https://raw.githubusercontent.com/rtk-ai/rtk/refs/heads/master/install.sh | sh

If the script put the binary elsewhere, move it:

find ~/.local ~/.cargo/bin ~/bin -name rtk 2>/dev/null
mv "$(which rtk 2>/dev/null)" ~/.local/bin/rtk

Verify:

~/.local/bin/rtk --version
chmod +x ~/.local/bin/rtk   # if needed

Step 2 — Identify the target agent group

ncl groups list

Note the group ID (e.g. ag-1776342942165-ptgddd). Repeat Steps 3–5 for each group.

Step 3 — Mount rtk into the container config

additional_mounts is a JSON array column on container_configs. Read the current value, merge in the rtk entry, and write the merged array back.

Read current mounts first:

pnpm exec tsx scripts/q.ts data/v2.db \
  "SELECT additional_mounts FROM container_configs WHERE agent_group_id = '<group-id>'"

Build the merged array: keep every existing entry, drop any entry whose containerPath is /usr/local/bin/rtk (so re-running replaces rather than duplicates), then add the rtk entry:

{"hostPath":"/home/<user>/.local/bin/rtk","containerPath":"/usr/local/bin/rtk","readonly":true}

Write the merged array back:

pnpm exec tsx scripts/q.ts data/v2.db \
  "UPDATE container_configs SET additional_mounts = '<merged-json>' WHERE agent_group_id = '<group-id>'"

Verify:

pnpm exec tsx scripts/q.ts data/v2.db \
  "SELECT additional_mounts FROM container_configs WHERE agent_group_id = '<group-id>'"

Step 4 — Add the PreToolUse hook to settings.json

Each agent group has a settings.json at:

data/v2-sessions/<group-id>/.claude-shared/settings.json

This file is mounted at /home/node/.claude/settings.json inside the container and is read by Claude Code for hooks, env, and model config.

Add the PreToolUse entry with jq. This drops any existing rtk Bash hook first, then appends a fresh one, so it is safe to re-run without creating duplicates:

SETTINGS="data/v2-sessions/<group-id>/.claude-shared/settings.json"

jq '.hooks.PreToolUse = ((.hooks.PreToolUse // [])
      | map(select((.hooks // []) | any(.command == "rtk hook claude") | not)))
    + [{"matcher":"Bash","hooks":[{"type":"command","command":"rtk hook claude"}]}]' \
  "$SETTINGS" > /tmp/rtk-settings.json && mv /tmp/rtk-settings.json "$SETTINGS"

Step 5 — Restart the container

ncl groups restart --id <group-id>

Verify

Confirm the binary is executable inside the container so a missing or non-executable mount surfaces immediately rather than as a silent hook failure:

docker exec "$(docker ps --filter "name=<group-id>" --format '{{.Names}}' | head -1)" rtk --version

Then ask the agent to run git status or any other supported command. rtk intercepts it silently. Check savings with:

~/.local/bin/rtk gain

Troubleshooting

rtk: command not found inside the container

Mount wasn't applied or container wasn't restarted:

pnpm exec tsx scripts/q.ts data/v2.db \
  "SELECT additional_mounts FROM container_configs WHERE agent_group_id = '<group-id>'"
# Look for entry with /usr/local/bin/rtk
ncl groups restart --id <group-id>

Hook not firing

Verify the hook is in settings.json:

jq '.hooks.PreToolUse' data/v2-sessions/<group-id>/.claude-shared/settings.json

If missing, re-run Step 4.

Binary won't execute — permission denied

chmod +x ~/.local/bin/rtk