Search every secondhand marketplace at once

The secondhand market is fragmented on purpose: the same vintage jacket might be $45 on Depop, $70 on Poshmark, and $30 (plus a drive) on Facebook Marketplace. Whoever checks the most marketplaces wins — but nobody wants to run the same search four times with four different filter UIs.

Cross-marketplace search fixes the mechanics. With Secondhand MCP connected to Claude or ChatGPT, a single "search all" query runs against Facebook Marketplace, eBay, Depop, and Poshmark simultaneously. The AI gets structured results from each — titles, prices, conditions, locations, photos — and does what AIs are good at: merging, comparing, and telling you which listing is actually the best deal.

What the workflow looks like

1. One request: "Search everywhere for a Patagonia Better Sweater, men's L, under $60."
2. Four searches run in parallel — no tabs, no re-typing filters per site.
3. The AI merges results: ranked by price, flagged by condition, local pickup vs. shipped noted.
4. You drill in: "show photos of the Depop one" pulls full listing details inline.

Who this is for

• Bargain hunters — the same item is routinely priced differently across marketplaces; checking all four is where deals live.
• Resellers — sourcing means spotting the price gap between marketplaces. One query surfacing a $30 local listing that sells for $80 shipped elsewhere is the whole job, compressed.
• Anyone furnishing or gearing up — for multi-item hunts (apartment furniture, camera gear, kids' equipment), serialized searching across four sites simply doesn't happen. One conversation does.

Plans

Individual marketplace searches are available from the free tier up. The one-shot "search all" fan-out is a Pro+ ($10/mo) feature — on lower tiers you can still ask the AI to search marketplaces one at a time. Deep-research tools (search/fetch), which also search all accessible marketplaces per query, are metered on every tier.