It is in the ChatGPT plugin directory as Secondhand Marketplace. Open it, connect, and ChatGPT can search real secondhand listings. It works as a Deep Research source too.
Nothing to install and no form to fill in. Connect it once and it is available in any ChatGPT chat. The free tier needs no credit card.
Takes about two minutes, once
Click Connect on the listing. A Secondhand sign-in window opens. Use your email (we send a one-click link) or Google, then click Allow. That creates your free account, with 10 searches a month and no card needed.
Ask ChatGPT for something. Copy this to start: Find a used road bike under $400 near Austin, TX
Secondhand MCP exposes the standard search and fetch tools ChatGPT Deep Research expects, so you can add it as a Deep Research source and have ChatGPT compile price research across marketplaces. For example, ask it to research the going rate for used Eames lounge chairs.
That is the name of our listing in the ChatGPT plugin directory. It is the same service as Secondhand MCP, and the account you create works in Claude and every other assistant too.
In the chat, click + and make sure Secondhand Marketplace is switched on, then ask again.
Yes. The server implements the standard search/fetch tool contract Deep Research expects, so it can be used as a research source.
No. Facebook Marketplace, eBay, Depop, and Poshmark all work with nothing to set up. You just sign in with your email or Google.
Yes. You get 10 searches a month with no credit card. Pro ($5/mo) raises the limits and adds Depop and Poshmark.
Plans are on our pricing page. Sign in on this website with the same email you connected with, and the plan applies in ChatGPT right away.
Yes, if you prefer: in ChatGPT open Settings → Plugins → Browse plugins, click +, and enter the server URL https://secondhandmcp.com/mcp with OAuth authentication. The directory listing is the same server. The manual path only skips the listing page.