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Seller Profit Doctor

For AI assistants

Ask your AI assistant where your shop’s money goes.

Claude, ChatGPT and other assistants that connect to MCP servers can run the free profit check-up and the fee calculators for you, for Etsy, Shopify and Amazon. They get the same numbers as this website, worked out by fixed formulas on each platform’s published, dated fees.

The server address

https://sellerprofitdoctor.com/api/mcp

Free. No account, sign-in or key. For people who build agents, the details are in llms.txt.

Is it working right now?

Every 10 minutes the site connects to this server over the internet, the way your assistant does, and runs five real steps: it says hello, lists the tools, runs the check-up on the example Etsy shop, works out Etsy’s fees on a $30 sale and reads the fee table. A step passes only when the answer is the right one, not just when an answer comes back.

Reading the latest test…

Or check it yourself: this connects from your own browser, right now, and runs three steps. Nothing is counted or kept.

The 9 free tools

Each one only reads and works something out. Your assistant picks the tool; you just ask in your own words.

  • sellerprofit_checkup

    The full profit check-up for an Etsy shop, a Shopify store or an Amazon seller: the grade in words, what each order and each month keep, and the three biggest losses, each with its fix and what it's worth.

  • sellerprofit_etsy_fees

    Etsy's fees on one sale, line by line, and what's left before your costs.

  • sellerprofit_offsite_ads

    What Etsy's Offsite Ads cost at your share of sales, and the item price that covers them.

  • sellerprofit_shipping_gap

    What labels and packaging cost beyond what buyers pay for shipping on Etsy, and the price that closes the gap.

  • sellerprofit_ads_breakeven

    The return at which Etsy Ads pay for themselves, the most an ad can cost per sale, and what yours gain or lose a month.

  • sellerprofit_price_for_margin

    The Etsy item price at which one order keeps the profit you want, and the break-even price.

  • sellerprofit_shopify_plan_fit

    Which Shopify plan costs least at your card sales, and the sales above which a bigger plan pays for itself.

  • sellerprofit_amazon_fees

    Amazon's fees on one unit: the referral fee, which is official, and the fulfillment fee, always marked as an estimate.

  • sellerprofit_rates

    Each platform's fee table, with the date every rate was checked and a link to its source.

Money is in US dollars. Every answer says which rates it used, the date they were checked and where they come from. Estimates, not financial, tax or legal advice.

Connect it

Claude

  1. On the web or in the desktop app, open Customize › Connectors.
  2. Choose +, then Add custom connector.
  3. Name it Seller Profit Doctor and paste the server address.
  4. If it asks how people sign in, choose No sign-in, then Add.
  5. In a chat, open + › Connectors and turn it on.

Or open Claude’s form with the address filled in, check it and choose Add.

ChatGPT

  1. Open Settings, then Apps and connectors. On plans that allow your own connectors, turn on developer mode under the advanced settings.
  2. Create a connector, name it Seller Profit Doctor and paste the server address.
  3. For sign-in, choose No authentication, then create it.
  4. In a chat, pick it from the tools menu.

Menu names change from time to time. If yours differ, look for a way to add a connector or MCP server by its address.

Other assistants and apps

Anything that connects to a remote MCP server can use the same address.

Address
https://sellerprofitdoctor.com/api/mcp
Transport
MCP over Streamable HTTP (JSON-RPC by POST)
Sign-in
None
Limit
60 calls a minute from one address

Things to ask

Say “use Seller Profit Doctor” the first time, so your assistant reaches for these tools.

  • “My Etsy shop gets about 100 orders a month. I sell a $30 item, materials are $8, buyers pay $5 shipping and the label costs $7. I've passed $10,000 in sales, and I spend about $10 a day on Etsy Ads at a return of about 1.5. Where is my money going?”

    What comes back: Grade: Watch. About $446 a month is lost at those numbers: shipping gap ($300), ads on Etsy that don't pay back ($104) and offsite Ads fees not priced in ($42). Each comes with its fix and what it's worth if orders hold.

  • “My Shopify store is on Grow, paid monthly, with about 200 orders of $35 plus $5 shipping. Products cost $12, labels $7, and I spend about $2,000 a month on ads at a return of about 2. What should I fix first?”

    What comes back: Grade: Good, with room to improve. About $498 a month is lost at those numbers: shipping gap ($400), a plan bigger than your sales need ($50) and ads that don't pay back ($38). Each comes with its fix and what it's worth if orders hold.

  • “What does Etsy take from a $30 sale with free shipping?”

    What comes back: $3.30: $0.20 to list, $1.95 transaction fee and $1.15 payment processing. About $26.70 is left before materials, packaging and the label.

  • “I'm on Shopify's Grow plan, paid monthly, with $8,000 a month in card sales. Am I on the right plan?”

    What comes back: Basic costs about $50 a month less at those sales: $271 against $321, price and card fees together. Grow pays for itself above about $33,000 a month in card sales.

At your numbers, if orders hold: an estimate from your own figures, never a promise. When an answer uses a default, your assistant should ask you for your real number.

What’s kept: nothing

  • The tools take numbers and fixed choices only, never your name, email, shop name or shop link.
  • What your assistant sends is used to work out the answer, then dropped. Nothing is stored.
  • Our logs keep one line per call: the tool's name, how long it took and whether it answered. Never what was sent.
  • To keep the free server fair, it counts calls from each address in memory for one minute and never writes the address down.
  • The status test above keeps only its own results: pass or fail, each step's time and the server's version.
  • Your conversation stays with the company that runs your assistant, under its own privacy policy.

Our privacy policy has the details.

A separate server lets an agent buy the profit report at $19.99 or the full audit at $29.99: the website’s prices, each paid once, with no subscription. Its address:

https://sellerprofitdoctor.com/api/mcp/agent
  • sellerprofit_buy_report prepares the report from the check-up’s answers and your email, and returns a payment link. It charges nothing itself.
  • sellerprofit_report_status says where a purchase stands.
  • Nothing is charged until the link is paid: by an agent that pays with Stripe's machine payments, from a wallet you set up, or by you in a browser on this website's checkout. Your agent should ask you first.
  • Refunds for any reason within 14 days. A purchase keeps the answer codes and your email only.

The free tools never take payment, send email or create a report. See the terms for who sells what.

A tool that isn’t working, or a question? Write to us.