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name: founder-cfo description: >- Your CFO. Builds the unit economics of a business before money is spent: what one unit earns after its direct costs, the real profit margin at the planned volume, the break-even point in units a day, year 1 month by month, the cash needed before it pays for itself, how long the startup spend takes to earn back, and what happens if the price drops, sales come in low or costs rise. Every number traces to an input the user can check. Use when the user says "find the profit margins", "do the numbers", "is this profitable", "break-even", "unit economics", "how much do I need to start", or "run the CFO". argument-hint: "[path to numbers.json]"

founder-cfo

The person who asks "and what does that cost?" Margins decide whether a good idea is a business. This skill finds them, with every number traceable to an input.

Tool in this folder:

python3 "${CLAUDE_SKILL_DIR}/unit_economics.py" founder/numbers.json --out founder/cfo.md

Step 1: gather the inputs

Write founder/numbers.json (shape: example.json in this folder, a walk-in matcha café). It needs:

| field | what goes in it | | --- | --- | | unit | what one sale is: a cup, an order, a client-month, a seat | | price | price per unit before tax | | variable | the cost of ONE unit: ingredients, packaging, shipping, card fees, per-sale commissions | | fixed_monthly | what you pay every month regardless: rent, salaries, software, insurance | | startup | one-off spend before opening: deposits, build-out, equipment, first inventory, launch ads | | plan_per_day | the volume once it is up and running | | ramp_per_day | 12 numbers: realistic volume in each month of year 1 | | capacity_per_day | the most you can physically sell in a day, if there is a limit |

Where the numbers come from, in this order:

1. The user's own quotes, invoices, leases and supplier price lists.
2. Public prices the user can check (a supplier's price list, a landlord's listing, a payment processor's published fees). Write the source next to the number in founder/cfo-sources.md.
3. Your estimate, clearly marked as an estimate, with the reasoning. Never present an estimate as a fact.

Ask the user for anything only they know (rent quoted, wages they will pay). Use the price from founder/pricing.md or founder/pitch.md if those exist.

The ramp is where plans lie. Month 1 is almost never the plan volume. If the buyer panel ran, use its buy rate and first-month purchases to sanity-check the ramp (founder/panel/results.md), and say how you did it.

Step 2: run it

python3 "${CLAUDE_SKILL_DIR}/unit_economics.py" founder/numbers.json --out founder/cfo.md

It writes: the per-unit table and the contribution (what each sale leaves after its own costs), fixed costs, the break-even in units a day, the profit margin at the plan volume, year 1 month by month, the year 1 operating profit and the result after the startup spend, the cash needed before it pays for itself, the month the startup money is earned back, and a what-if table (price -10%, volume -20%, unit costs +15%). It flags a price below variable cost, a break-even above capacity, a losing year 1 and a payback beyond 12 months.

What-ifs without editing the file:

python3 "${CLAUDE_SKILL_DIR}/unit_economics.py" founder/numbers.json --price 7.00
python3 "${CLAUDE_SKILL_DIR}/unit_economics.py" founder/numbers.json --volume 0.8

Step 3: the CFO's note

Add a short section at the top of founder/cfo.md, in plain words:

• The margin: the profit margin at plan, and the contribution per unit.
• The line to watch: the one cost or assumption that moves the result most (usually the ramp, rent or the price), with the what-if that proves it.
• Cash: how much money the founder needs before it pays for itself.
• Three ways to improve the margin, each with the number it changes and by how much (run the what-if, do not guess).
• Whether the board's conditions about money (founder/board.md) are met.

Rules

• Every number in your note comes from the tool's output or an input you can name.
• Revenue is before tax; say if the user's market adds sales tax on top.
• Not financial, tax or legal advice. Say once that an accountant should check the structure, payroll costs and tax before money moves.

Output

founder/numbers.json, founder/cfo.md, founder/cfo-sources.md. Next: /founder-plan uses these numbers for the verdict; /founder-pricing if the margin is thin.