The Cost Control Card

Arun Nagarathanam · 2 Sep 2026 · Checklist · 50 of 59 in this course

An exclusive resource for students of Arun's Claude Code Course.

A one-page habit sheet for keeping a session cheap. None of this is about a smaller plan. It is about not paying to re-read the same conversation over and over. Pin it somewhere you will see it for your first few weeks.

The five habits

1. Clear between unrelated tasks.

The moment you start something that has nothing to do with what you just did, type /clear first. Your files are safe on disk. You are only wiping the conversation, the expensive part Claude re-reads on every turn. This is the single command that saves the most money in the whole tool.

2. Steer compact instead of trusting it.

When you do want to keep the thread, /compact squeezes the conversation into a summary. Add an instruction after it, like /compact keep the database decisions, drop the styling back-and-forth, and it keeps what you named instead of guessing for you.

3. Respect the cache timer.

When the conversation has not changed, Claude can reuse much of what it already processed. On a Claude subscription, the cache Claude requests lasts about 1 hour. API use can have a different cache duration, including a shorter 5-minute option. If you return after a long break, check whether the same session still helps the task or whether a clean handoff is cheaper and clearer.

4. Give your helpers a cheaper brain.

When you build little helpers that run on their own, they can inherit the parent model unless you tell them otherwise. Pointing them at a cheaper, faster model can save a meaningful amount when the task is simple. Set this where your project keeps its configuration, and confirm the exact setting for your version when you get there.

5. Watch the meter on purpose.

Type /usage the way you glance at a fuel gauge, long before the light comes on. It reports an API-value estimate, which is useful for comparing sessions even when a subscription includes your usage. Every helper you load and every long notes file gets sent to Claude at the start of every session, so a glance at /usage is how you notice overhead you did not mean to carry.

The one-line version

Clear between unrelated work. Steer compact when you keep a related thread. Check the session after a long break. Match helper models to the task. Glance at the meter.


See Where You Stand

This resource is one piece of a much bigger system.

Take the free Claude Code Readiness Quiz. It is 15 short situations, scored out of 100, and it tests how you handle a job rather than what you know about a tool, so you can take it without ever having opened Claude Code.

Take the Claude Code Readiness Quiz →

15 situations · Scored out of 100 · Free