Brief Your AI

Build a Small Tool for Your Team with AI: An Expense Calculator You Can Trust

Build an expense calculator page for your team.

Level 3 · Agent Paid · 30 minutes · Updated Oct 31, 2026

Draft: not yet reviewed.

Every team has a small, annoying calculation that everyone does slightly differently: how much of a trip can be claimed, how many vacation days are left, what a quote should cost. AI can now turn a description of that calculation into a working web page in a few minutes, with no coding. That’s genuinely useful, and it raises the stakes: once colleagues use your tool, its mistakes become their mistakes. In the next 30 minutes you’ll build a small expense calculator for your team, prove it gives the right answers, and share it without exposing anything you shouldn’t.

Remember the intern: smart, fast, first day on the job. They write working code in seconds. But they’ve never read your expense policy, they’ll quietly fill any gap in your rules with something that “seems reasonable”, and they won’t think of the colleague who types “0” nights or a negative number. Your job today is writing the rules down properly, testing like a skeptic, and deciding who gets the link.

What you'll get

The resultA one-page expense calculator: enter mileage, trip days, city type, hotel nights and other costs; it shows what can be claimed, flags anything over the limits or missing a receipt, and shows how each number was calculated. Plus a one-page spec with test cases, so you can update it later
LevelLevel 3: the AI writes, runs and delivers a working tool. You do it from a normal chat, which makes it the easiest way into Level 3
Loop step you'll practice“Give instructions” in its most formal version, a written spec. And “you check” in its most objective version: test cases with known answers
Time30 minutes, then about 10 minutes each time the policy changes

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