The Costs,
In Brief.

A personal AI assistant runs on your own machine, bills you per thought, and charges extra only for the senses you add.

What does a desktop AI assistant cost to run each day? Less than you fear, once you see the cost one action at a time. Your assistant runs locally on your computer with no subscription. The thinking runs on your own API key, prepaid in small amounts and metered like electricity. Every feature below carries a price, so you know the number before you build.

The Bill
You Never See.

Opening question: what did your AI tools cost you last week, per task?

You started the job or the business with a dozen tabs open and nobody to hand work to. You watched someone talk to a desktop assistant, open their calendar by voice, draft an invoice, and take a phone call. You wanted one. Then you stopped at the same wall everyone hits. Nobody tells you what the thing costs to run.

So you guess. Some people skip the build because an API key feels like an open tab at a bar. Others run every request through the most expensive model, let the agent click around their screen for minutes at a time, and open a bill at the end of the month with no idea which action drove the total.

Both mistakes come from the same gap. You treat the assistant as one product with one price. A working assistant is a set of separate actions, each with its own price. Opening a file costs zero. A sentence back to you costs a cent and a half. Driving your screen costs fifteen cents. A phone minute costs up to thirty.

The three groups

01 / Sort Every
Move First.

Before you build, list what you want the assistant to do and tag each action F, M, or A.

Your first move is a sort, not a build. Every feature lands in one of three groups. Reading your notes, checking your memory, and opening Gmail or Calendar happen on your machine or through access you already granted, so they cost nothing. The moment the assistant thinks and answers, the meter runs. Voice and phone sit outside both, on separate vendor plans.

Do the same with your own week. Write down ten things you want an assistant to handle. Tag each one. A meeting reminder pushed to your phone is F. A summary of yesterday's client email is M. A call to reschedule a vendor is A plus M.

What the sort reveals

Most new professionals find six or seven of the ten tasks land in M, two or three in F, and one in A. The F tasks are your free wins. Build those first. The A tasks hold most of the cost risk. Build those last.

02 / Give The
Brain Its Own Bill.

One key, one purpose, one prepaid balance. You read the assistant's cost the way you read a utility bill.

Run your assistant on its own API key, apart from your Claude Code or GPT-6 Astra subscriptions. The reason is simple. When the assistant shares a bill with your daily work, you never learn what the assistant costs. When the assistant has its own key, every cent on the statement belongs to one system.

Prepay a small amount. Ten dollars covers about 660 replies at 1.5 cents each. Turn off auto-reload for the first month. When the balance runs low, you get a signal instead of a surprise.

Set up the separate bill

04 / Route Cheap
Before You Think.

The cheapest token is the one the expensive model never reads.

Give your assistant a small pre-router before the main model sees a request. The router costs under a cent and answers five questions. Which lane does this request take? Has the speaker finished? Is the speaker talking to the assistant or narrating to a camera? Does the request need a tool or a call? Does the vault already hold the note?

The third question saves the most money for anyone who talks out loud while working. Without the check, every sentence you say near the microphone becomes a paid request.

Build your own routing rules

05 / Fence The
Expensive Moves.

Screen takeovers and phone calls do real work in real accounts. Give them a stop word, a cap, and a short list of allowed jobs.

The two most expensive actions also carry the most risk. A screen takeover clicks through your actual accounts. Ask for a new ad campaign and the assistant opens Meta Ads Manager and starts building. One step past the setup and the assistant sets a budget with real money behind the number. A phone call speaks for you to a real person, billed by the minute, hold time included.

Give yourself a spoken stop phrase such as "that's enough," and have the assistant answer "hands off" when control returns to you. Write the limits down before the first run.

The fence

Counterpoint.

The price card is useful. The price card is also incomplete.