Margin Guard

    2

    Calculates break-even and target CAC from your own Etsy/Shopify cost data — no fixed 2.2x or fee-percentage rule unless you choose one.

    $17

    Secure checkout via Stripe

    Money-back guarantee

    Converts to your local currency at checkout

    Security scanned

    Works with the AI Agents you already use

    Claude CodeClaude CodeCursorCursorCodex CLICodex CLIDeepSeekDeepSeekMuseMuse+22 more

    Margin Guard

    Example session with this skill installed

    (Synthetic example.) I sell a t-shirt on Etsy. The buyer pays $35.00 with no discount. My Printify base cost is $12.50, supplier shipping is $5.25. Etsy's payment/transaction fee on this order is a real $2.28. My return/reprint buffer is a flat $1.05. I want at least $5.00 profit per order after ad spend. Also: I spent $150 on ads last week but got 0 confirmed orders from that batch — what's my real CAC?

    • Read your context and instructions
    • Compiled the margin guard

    (Synthetic example — all figures below come directly from running the skill's own script on the inputs above; nothing is estimated.)

    Part 1 — break-even and target CAC

    Line itemAmount
    Amount charged to customer (no discount)$35.00
    Product/fulfillment cost-$12.50
    Supplier shipping cost-$5.25
    Platform/payment processing fee (your real amount)-$2.28
    Return/reprint buffer-$1.05
    Break-even CAC$13.92
    Target profit per order (yours)$5.00
    Target CAC$8.92

    Result: MEETS USER-SELECTED THRESHOLD — with the numbers you gave, you can spend up to $8.92 per order on ads and still hit your $5.00 target profit. This is a calculation from the data you entered, not a guarantee.

    Part 2 — your real ad spend, 0 confirmed orders

    You gave $150.00 in real ad spend and 0 real orders acquired.

    Realized CAC: cannot be calculated. With zero orders there is no valid count to divide the spend by. This does not mean your CAC is infinite or zero, and it does not mean the campaign failed; it means there is nothing yet to compute a real CAC from. Your break-even CAC ($13.92) and target CAC ($8.92) above are unaffected because they come from your cost data, not ad performance.

    Next step: once you have at least one confirmed order from that ad batch, realized CAC = real spend ÷ real orders. Report back with a number greater than zero and the skill will calculate it.

    Connects securely to your tools. The creator never sees your data.

    About this skill

    The problem

    E-commerce sellers often ignore landed costs, real platform fees, and the difference between break-even and target CAC — which makes products that look profitable on paper lose money in reality. Manually separating these numbers for Etsy or Shopify across different suppliers is slow and easy to get wrong.

    What it does

    • Calculates landed cost (product cost + supplier shipping) and separates break-even CAC from target CAC — never the same number.
    • Uses your real platform/payment fee (a rate you give, plus its base, or an exact amount) and your real return/reprint buffer — never an assumed or default percentage.
    • Handles discounts, VAT/sales tax, and customer-paid shipping as distinct, non-overlapping inputs, so nothing is double-counted.
    • If you explicitly choose an example multiple (e.g., "use 2.2x"), evaluates it and always labels it as your own choice — never a system rule. If you choose none, no fixed number is applied.
    • States the result as one of four clear states — cannot calculate, negative unit economics, doesn't meet your target, or meets your chosen threshold — never a universal "list / don't list" verdict.

    Why this beats prompting it yourself

    General AI often blurs break-even CAC, target CAC, and realized CAC into one number, or quietly assumes a platform fee instead of asking for your real one. This skill keeps those three concepts separate, refuses to guess a missing fee or a missing order count, and never substitutes a "standard" threshold for your own numbers.

    Use cases

    • Checking whether a new Printify product can break even before syncing it to an Etsy storefront.
    • Comparing two suppliers' total landed cost side by side, using your own numbers for each.
    • Working out the minimum price a Zendrop drop-shipping listing needs to hit your target profit per order.
    • Telling apart a pricing problem (negative unit economics) from an advertising problem (CAC too high) before you touch ad spend.

    Known limitations

    Every number must come from you or an integrated source — the skill never assumes a "standard" Etsy/Shopify fee percentage, a discount basis, or a currency conversion rate; if one of the required inputs is missing or currencies are mixed without a stated rate, it stops and asks rather than guessing. This is not financial, tax, or legal advice, and it does not guarantee sales or profit — verify current platform fees on your own dashboard.

    Find more skills like this on the Claude Skills Marketplace, the Codex Skills Marketplace and the Gemini Skills Marketplace, or browse Claude Skills for Shopify.

    Requires you to supply real numbers for every fee, buffer, and (if used) discount/tax field — the skill will not substitute a "typical" Etsy/Shopify rate for a missing one. An example multiple like 2.2x is only evaluated if you explicitly ask for it. Realized CAC requires a real, positive order count; with zero orders it reports "cannot calculate" rather than a number. This is illustrative, not financial, tax, or legal advice, and platform fees change over time — verify current rates on your own dashboard.

    How to use

    1. 1

      Connect your agent to the Agensi MCP

      Copy the prompt and paste it into Claude, ChatGPT, Cursor or any agent that supports MCP. It sets up the connection for you. Manual setup

    2. 2

      Sign in to Agensi

      Your agent shows a sign-in link. Sign in and click Allow.

    3. 3

      Ask for what you need

      Your agent loads this skill and uses it on your task. It always asks before buying a skill.

    Reviews

    No reviews yet

    Be one of the first to try it. Every listed skill goes through the trust checks below.

    Security scanned

    Checked by our 8-point scan before listing

    Fresh listing

    Recently published to Agensi

    Money-back guarantee

    Doesn't do what its page promises? You get your money back.

    Trust & safety

    Security scan

    Security scan passed 1 month ago

    Permissions

    Terminal / Shell
    Listed2 months ago
    Updated1 month ago

    What's inside

    Frequently Asked Questions

    Margin Guard doesn't assume a fee percentage for either platform — you give it your real transaction fee, payment/FX fee, and return-buffer numbers (a rate plus its base, or an exact amount), and it calculates from those. If you also want to check a COGS or CAC target, that's a number you choose, not a built-in limit.

    You get the SKILL.md instructions and the Python calculation script (margin.py) that compute break-even CAC and, when you provide a target profit, target CAC — from your own cost, fee, and buffer data. No fixed threshold is built in; an example multiple is used only if you explicitly choose one.

    No, this skill functions as a logic layer for your AI agent; you will manually provide the base cost and shipping data, and the agent will return a mathematical viability audit.

    Margin Guard is compatible with any major LLM (like GPT-4, Claude, or Gemini) that supports custom system instructions or agentic workflows.

    Yes — run the same calculation once per supplier with each one's real base cost and shipping, then compare the break-even CAC each produces. The result is only as accurate as the numbers you provide; the skill doesn't estimate or guess a supplier's rates for you.

    Buyers receive lifetime access to the current version of the skill, and any critical updates regarding platform fee changes (like Etsy fee hikes) will be made available via the marketplace.

    New in E-commerce