What this actually costs

Most courses put the price in the footnotes. This one puts it in lesson two, because the whole point of the course is running more than one session at a time, and more sessions cost more money. You should decide about that now, not in module 4.

There is no free Claude Code

This is the sentence people are most surprised by, so it goes first and plainly. The free Claude.ai plan does not include Claude Code. A free account lets you chat on the website. It does not let you run the thing you installed in lesson 1.

Claude Code needs one of these:

• A Claude subscription — Pro, Max, Team or Enterprise. This is what most readers of this course have or will get.
• A Claude Console account with pre-paid credit. No subscription, no monthly commitment. You add a few dollars and it draws down as you use it. This is the cheapest honest way to work through this course if you are not ready to commit.
• Access through a supported cloud provider, if your employer already has one. If that applies to you, you already know.

If you are in India, two extra facts belong in this decision before you spend anything. Anthropic localised pricing to rupees in July 2026, so you will be quoted in ₹ rather than converted dollars. And website subscriptions still need a credit or debit card: there is no UPI option, which is a genuine obstacle and worth knowing before you get to a payment page and find out. Check the current number on the pricing page rather than trusting any figure printed in a course, this one included. Prices move and courses do not.

The stray key that overrides the door you chose

There is one trap worth knowing before you go any further, and it is narrower than the version you will read elsewhere. If ANTHROPIC_API_KEY or ANTHROPIC_AUTH_TOKEN is set in your environment, that credential takes precedence over your claude.ai login. People end up with one after following an unrelated tutorial months earlier, and it then sits in the environment for the rest of the year.

Two documented consequences follow, and you will meet both later in this course. In module 5, /schedule is simply not there, because cloud routines need the subscription login and the variable hides the command. And a scripted claude --bare run never reads your saved login at all, so it needs that key set on purpose — the same fact seen from the other side.

So check whether the variable is set before you conclude anything is broken, and unset it if you did not mean it. Ten seconds now, or an afternoon in module 5.

Your installation has a read-only check of its own, and it is the first thing to run when something behaves oddly:

claude doctor

A report on your install and your settings — where the binary is, which version it is, and what is misconfigured. It changes nothing; it only tells you.

Watching your own spending

One command, and it has an alias so you will see it written both ways.

/usage

A session block: total cost, API duration, wall-clock duration, lines changed, and a per-model breakdown.

Two keys make it more useful than it first looks. Press d for the last 24 hours and w for the last 7 days. The longer views break your usage down by skill, subagent, plugin and individual connected tool, as percentages. That is the panel you open when the month feels expensive and you want to know what is actually eating it rather than guessing.

One thing to expect: the session totals reset when you run /clear. That is deliberate, since /clear starts a fresh conversation, but it does mean the session number is not a running total for the day. Use the 24-hour view for that.

The number that matters for this course

Here is the sentence to carry into module 3, where you open a second terminal:

Running ten agents in parallel uses quota roughly ten times as fast as running one.

That is not a warning against parallel work. It is the price of it, stated honestly. Parallel sessions do not make the same work cheaper; they make waiting shorter. If the value of your time exceeds the value of the tokens, that trade is obviously worth making, and if it does not, it obviously is not. You now have the command to check which side you are on.

For scale, Anthropic publishes an enterprise average of about $13 per developer per active day, with 90% of users staying under $30 on a day they actually work. You are almost certainly lighter than a full-time engineer. But an active day with four sessions running is not a light day, and module 3 has a whole lesson on keeping that number down.