Install Sprag, the Claude Code token saver
Install the Sprag command-line harness for Claude Code with one npm command, register the statusline and hooks, and verify the setup.
Getting started
Prerequisite: Node.js ≥ 18 (node -v · macOS brew install node · Windows winget install OpenJS.NodeJS.LTS · Linux/WSL: nvm recommended)
npm i -g sprag-cliThe statusline appears at the bottom of Claude Code right away. If auto-registration was skipped (--ignore-scripts, sudo, sandboxed installs), run sprag install.
One install sets up everything: statusline, Skill, SessionStart hook, the 🅷 Harness (5 principles), and a first route-scan. The harness and the Korean writing guidance show what they add and ask before enabling it. The harness is appended to ~/.claude/CLAUDE.md as a marked block (your existing content is backed up and preserved) and is left alone if one is already there.
Outside a terminal — npm postinstall, CI, piped stdin — the question is skipped and the old defaults apply. Use --yes or --no-input to skip it deliberately, CTS_NO_HARNESS=1 npm i -g sprag-cli to skip the harness entirely, and sprag harness uninit --global to undo it.
⚠️ Avoid
sudoglobal installs — the Skill lands in root's~/.claudeinstead of yours. Use nvm/fnm/Volta ornpm config set prefix ~/.npm-global.
What the install turns on, and what stays manual
Everything that costs nothing until it is needed is on after a plain install. The only manual items are the ones that change Claude Code's own settings or need a human to pick a scope.
| Feature | After install | How to turn it off |
|---|---|---|
| statusline (diagnostic chips, savings ledger) | on | sprag uninstall |
/claude-token-saver Skill | on | same |
| SessionStart hook (route-scan refresh) | on | same |
| UserPromptSubmit hook (brief injection) | on | same |
| First route-scan (last 14 days of logs) | runs once during the install | n/a |
🅷 Harness 5 principles (~/.claude/CLAUDE.md) | on (shown and confirmed once at a terminal) | harness uninit --global, CTS_NO_HARNESS=1 |
| doc2md hooks (Read, Edit/Write, prompt) | on | doc2md off, CTS_NO_DOC2MD=1 |
| doc2md converter (markitdown venv) | offered at a terminal; an unattended install prints the command | install later with doc2md install-converter |
| Korean writing guidance | on when the locale is Korean (asked at a terminal) | korean off, CTS_NO_KOREAN=1 |
| compact-window warning chip | on | compact-window off |
| Update-available chip | on | CTS_NO_UPDATE_CHECK=1 |
Pinning compact-window (autoCompactWindow 500k) | off — run it yourself | compact-window set --global or --project |
Model-fitting rules (ratchet-model.md delegations) | candidates are proposed only | review and approve with route-scan rules |
handoff (back up work before a cap) | an on-demand command | n/a |
compact-window set writes into Claude Code's settings.json and a human has to choose global or project scope, so it is never run for you. Model-fitting rules keep an approval step for the same reason: which work belongs on a cheaper tier is your call.
More docs
- Claude Code statusline: cache hit rate, cache TTL countdown, 5-hour and 7-day rate limits
- Why realtime model routing can cost more in Claude Code
- Delegate repeat Claude Code work to Haiku and Sonnet subagents with route-scan
- Claude Code harness: ratchet rules, evidence-gated completion, Plan-Execute-Verify
- Convert pptx, xlsx, pdf, docx and fig to Markdown before Claude Code reads them
- Claude Code statusline behind LiteLLM and other gateways
- Sprag command reference
- Korean writing style gate for Claude Code output