AI models and credits: how to optimize usage

Two things quietly decide how far your money goes with an agent. Which model you point at a job, and how much you make it read and write to get there. Get both wrong and a week’s allowance is gone by the afternoon. Get them right and the same allowance stretches for days.

Almost none of this is about spending more. Most of it is about not paying for things that buy you nothing.

Why you run out of credits so fast

The problem is rarely heavy use. It is expensive use on cheap work. Two reflexes do most of the damage.

1. The biggest model, every time. The top model is built for long, involved problems, the kind that used to take a person a full day or a week. Renaming a batch of files or drafting a subject line is not that. A smaller, cheaper model handles it just as well and faster, and it sips where the big one gulps.

2. Maximum thinking on a simple ask. Deep reasoning modes and fleets of parallel agents exist for genuinely hard problems, and they are not cheap. Anthropic’s own figures put a multi-agent run at around fifteen times the tokens of a plain chat. Point that at a five-minute task and you pay a fortune for an answer you would have gotten anyway.

A lighter, cheaper setup often gets you more, not less, because it does the job and leaves you credits to keep going.

Which model for which job?

Sort the work into three buckets and the choice mostly makes itself.

You do not need the exact names. Your tool’s model menu lists them, often with a cost or speed hint, and the buckets tell you which to grab. Most marketing work lives in the first two rows, and the heavy model is the exception, not the default.

What are you actually paying for?

You pay for tokens, roughly chunks of words, and you pay for them twice. Once for everything the agent reads, and again for everything it writes.

• The model sets the rate. The same task costs several times more on the top model, word for word.
• The session sets the volume. A long thread hauls its whole history; a fresh one starts light.
• Big inputs do the same up front. The one file the task needs costs less than the whole folder.

How you pay decides how a mistake feels. A subscription hands you a monthly allowance and a ceiling on surprises, which is where most people should start. Pick the middle tier when you do, not the strongest plan. The top one is real money for headroom most marketers never touch, and you can move up the week you need to. Paying per use through an API key charges for exactly what you run, which is powerful and unforgiving.

Some tools, Codex among them, let you keep working on paid credits once your included usage runs out. Check that setting before a heavy session, so a quiet afternoon does not quietly turn into a bill.

The habits that make a session last

A short list of habits carries almost all of the benefit.

• Match the model to the job. The strong model for real reasoning, a tricky positioning call, a messy analysis. The cheap model for the mechanical majority, which is most of what you do.
• Start clean between tasks. A new job deserves a fresh session. In Claude Code that is /clear. Do not drag an hour of unrelated history into a two-minute request.
• Compact before you are forced to. When a session gets long, /compact sums it up and hands the space back, and you can tell it what to keep. Doing that yourself around the halfway mark beats letting the tool scramble at the limit.
• Point at the part, not the whole. Give it the one file, or the few lines, the task needs. Reading a whole folder to change a sentence is the most common quiet waste there is. The whole-folder read you ran on Tempo was the exception that proves it: that task was the folder.
• Keep the stable stuff in the context file. Rules and facts the agent needs every time belong in the file it reads on every task, not retyped into each session. You watched Tempo’s file do exactly this; yours does it once you write it in the Build your marketing brain tutorial.
• Glance at the meter. Most tools show how much you have burned through. Watch it for your first week, and after that you will know what things cost without checking.

Why credits will not stay this cheap

Right now, credits are cheap the way an Uber ride was cheap in 2016. The flat monthly plans are widely reported to be priced below what they cost to run, subsidized with investors’ money to win the market. Even the priciest plans reportedly run at a loss.

As I write this in July 2026, that subsidy is starting to unwind. The flat plans that defined the last two years are being capped, tiered, and metered. The discounts still running are papering over the real number into the autumn. The strange part is that a single word costs the models less every month. Yet the bill for real work keeps climbing, because agents now eat so many more words, and nobody is passing the savings on.

That is the good news, oddly enough. The habits above are worth a little today and a lot soon. Build them now, while the meter is still generous, and the next price step is a shrug instead of a wall.