For AI assistants

Price anything from inside Claude, ChatGPT or your coding assistant

Underpriced AI is an MCP server. Add one URL to your assistant and it can tell you what a thrift find sells for on eBay, show you the real sales behind the number, and say whether it is worth buying at the price in front of you. No account needed for a few calls a day.

Server URL

https://underpricedai.com/api/mcp

What your assistant can do

price_item
What it sells for on eBay, from a photo link or a description: a calibrated estimate with a range, the recent sold comps behind it, three list prices with the two-week sell chance, the net after eBay fees, and a worth-it verdict when you say what you would pay.
get_sold_comps
The most recent real eBay US sales for a search, with the count, median and quartiles. Best Offer sales are shown at eBay's asking price and counted at a typical offer discount.
worth_it
Net after eBay fees and a plain verdict for an expected sale price and a cost. Worth it, thin, or pass.
buy_credits
Lists the credit packs and, once you are signed in, your balance and a checkout link for the pack you pick.

Try asking: "What would this Pyrex Butterfly Gold bowl sell for?" or "Here is a photo link of a vase I found for $8. Worth it?"

Connect it

Claude (web and desktop)

Settings, then Connectors, then Add custom connector. Name it Underpriced AI and paste the server URL. Leave authentication empty.

ChatGPT

Settings, then Connectors, then Create (developer mode may need to be on in Advanced). Paste the server URL and choose no authentication.

Claude Code

claude mcp add --transport http underpriced https://underpricedai.com/api/mcp

Then type /mcp and choose Authenticate to sign in. Claude Code inside WSL, a container or a remote machine? After you click Allow, copy the link on the next page and open it from that environment with curl while the sign-in dialog is still open.

Cursor, Windsurf and other MCP clients

{
  "mcpServers": {
    "underpriced": { "url": "https://underpricedai.com/api/mcp" }
  }
}

Clients that only speak stdio can use mcp-remote:

npx -y mcp-remote https://underpricedai.com/api/mcp

Sign in for your own account

When you add the connector, Claude or ChatGPT will offer to sign you in to Underpriced AI. Signed in, a photo price is a real scan on your account: it uses your credits or plan, lands in your scan history, and the result links to the saved scan so you can list it on eBay in one step.

Out of credits? Ask the assistant to buy a pack, or turn on pay as you go below: a card on file once, then every photo scan bills $0.25 on a monthly invoice with no cap and nothing to top up.

Pay as you go

$0.25 per photo scan, billed at the end of the month. It only kicks in when you have no free scan, credits or plan allowance left, so it never costs anything while a plan or pack covers you. Turn it off any time.

Checking your account

Limits for anonymous use

Without signing in, use is capped per day: a few photo prices, ten text prices and forty sold-comps lookups per caller, with a daily ceiling for everyone. Prices are in USD for eBay US.

A photo scan in the app reads marks, sizes and condition a description cannot carry, gives you the full comp list, and lists the item on eBay in one step. Your first scan is free.

Scan an item free Help center