Use Finance vs Cash in your AI

Install one skill in Claude, ChatGPT or Grok, then ask your question in plain words. Your AI looks up what you did not say, lists every assumption with its source, and replies with one link that opens Finance vs Cash on your scenario. The tool works out the answer, so the figures you see are the tool's, not the chatbot's.

 Download brotools-financingvscash.zip Open the tool

A .zip skill: SKILL.md (how to answer), references/ (every input, its range and the Quick Starts) and scripts/build_link.py (builds and checks the link). Read SKILL.md

Install the skill

Pick your assistant. The demo plays the steps; press a step to jump to it.

    Menus move as these apps update; look for Skills in Settings. Skills need the app's code tool switched on (Claude: Code execution and file creation). No skill support on your plan? Attach brotools-financingvscash.zip or SKILL.md to the chat and say "use this skill".

    How to use it

    Ask as you would ask a friend. With the skill on, the AI keeps your figures, researches the rest, and hands you the link. It does not give the answer itself: the tool does, once you open the link.

    should I pay cash for a $45,000 car or take a 5-year loan at 7.9% and invest the cash?

    Using skill brotools-financingvscash Ran scripts/build_link.py: link checked

    Your inputs

    • Cash Purchase Cost: $45,000

    Assumptions

    1. Cash on hand: 60,000, which the user did not state, kept at the car Quick Start's level so the cash covers the price.
    2. The loan: a single offer over 5 years at 7.9% a year, repaid monthly, with no deposit and no fees because the user mentioned none. It replaces the car Quick Start's three offers.
    3. Interest on spare cash: 4.5% a year, a typical savings or term deposit rate, used for the cash that is invested instead of spent.

    Your scenario

    Open Finance vs Cash on this scenario

    https://tool.adjiebrotots.com/financingvscash/#load&v=1&qs=car&purchaseCost=45000&availableCash=60000&why.availableCash=The%20user%20did%20not%20say%20how%20much%20cash%20they%20hold,%20so%20a%20round%20amount%20above%20the%20price,%20as%20the%20car%20Quick%20Start%20assumes&offers=5-year%20loan%20at%207.9%25:financeRate=7.9:termYears=5&why.offers=One%20loan%20over%205%20years%20at%207.9%25%20a%20year,%20paid%20monthly%20with%20nothing%20down%20and%20no%20fees,%20since%20none%20were%20mentioned&baseRf=4.5&why.baseRf=A%20typical%20savings%20or%20term%20deposit%20rate%20for%20the%20cash%20that%20is%20invested%20instead&note=Car%20purchase,%20October%202026

    Open the link to see the result.

    Open this scenario
    • Your figures stay yours. Anything you state goes in as you said it; correct any assumption and the AI sends a new link.
    • Checked before you see it. The skill's script checks every input's name, range and choices before the AI sends the link, so it opens the scenario listed.
    • The tool shows what the AI chose. When the link opens, a banner lists each value the AI set and why, with an Undo back to your own inputs.

    Ready to try it?

    Download the skill Read the guide Open the tool