Secondhand MCP

A Model Context Protocol (MCP) server that lets AI assistants search secondhand marketplaces. Search Facebook Marketplace, eBay, Depop, and Poshmark for used and secondhand items — filter by price, category, condition, size, and color, then get full listing details with photos, descriptions, and seller info.

Works with Claude Desktop, Claude Code, Cursor, and other clients that run MCP servers locally.

> [!TIP]

> Using ChatGPT? This one won't work there.

>

> It runs on your computer, so it only works where your computer is — Claude Desktop, Claude Code, Cursor. Secondhand MCP Cloud is the same search, always on, so whichever assistant you actually use can reach it. Free tier, no card.

Supported Marketplaces

Setup

Claude Desktop

Add to `~/Library/Application Support/Claude/claude_desktop_config.json`:

{
  "mcpServers": {
    "secondhand": {
      "command": "npx",
      "args": ["-y", "secondhand-mcp"],
      "env": {
        "EBAY_CLIENT_ID": "your-ebay-client-id",
        "EBAY_CLIENT_SECRET": "your-ebay-client-secret",
        "EBAY_MARKETPLACE_ID": "EBAY_US"
      }
    }
  }
}

Claude Code

Add to `~/.claude/.mcp.json`:

{
  "mcpServers": {
    "secondhand": {
      "command": "npx",
      "args": ["-y", "secondhand-mcp"],
      "env": {
        "EBAY_CLIENT_ID": "your-ebay-client-id",
        "EBAY_CLIENT_SECRET": "your-ebay-client-secret",
        "EBAY_MARKETPLACE_ID": "EBAY_US"
      }
    }
  }
}

eBay, Depop, and Poshmark are all optional — if eBay API keys are missing or Chrome isn't installed, those marketplaces are automatically disabled and the rest still work.

Depop & Poshmark / Chrome Requirement

Depop and Poshmark require a headless browser. If Google Chrome or Chromium is installed on your system, both are automatically enabled — no config needed. If Chrome isn't found, they are silently skipped.

On macOS, the first time you search Depop or Poshmark, you may see a system prompt asking to allow Node.js to control Chrome. This is expected — puppeteer needs to launch Chrome in headless mode. Allow it once and it won't ask again.

The browser runs invisibly in the background and only launches when you actually search Depop or Poshmark.

Configuration

Choosing Marketplaces

By default all marketplaces are enabled. To limit which are active, set the `MARKETPLACES` env var (comma-separated):

{
  "env": {
    "MARKETPLACES": "facebook,ebay"
  }
}

Valid values: `facebook`, `ebay`, `depop`, `poshmark`

eBay API Keys

eBay uses the official Browse API. You need a free eBay developer account:

1. Create an account at developer.ebay.com

2. Create an application to get a Client ID and Client Secret

3. Add them to your MCP config as `EBAY_CLIENT_ID` and `EBAY_CLIENT_SECRET`

eBay Marketplace / Region

By default the server targets the US eBay site. To search a different regional marketplace, set the `EBAY_MARKETPLACE_ID` environment variable:

{
  "env": {
    "EBAY_MARKETPLACE_ID": "EBAY_DE"
  }
}

Common values:

The full list is available in the eBay API docs.

Tools

`search_marketplace`

Search for items across marketplaces.

Data returned per marketplace:

`get_listing_details`

Get full details for a specific listing using an ID from search results.

Data returned per marketplace:

`list_marketplaces`

List all enabled marketplaces and their status.

`search` / `fetch` (deep research)

Convenience pair following the ChatGPT Deep Research tool contract — exact names, a single string argument each:

• `search(query)` — searches every enabled marketplace at once and returns `{ results: [{ id, title, text, url }] }`, where `id` is `marketplace:listingId`
• `fetch(id)` — returns full listing details for a `search` result ID as `{ id, title, text, url, metadata }`

Useful for research-style clients that expect these standard tool names; for filtered searches use `search_marketplace`.

How It Works

Facebook Marketplace — Searches listings by location, price, and query. Resolves city names to coordinates. No login or browser needed.

eBay — Uses the official eBay Browse API with OAuth 2.0 client credentials. Tokens are cached and auto-refreshed. The target regional marketplace is controlled by `EBAY_MARKETPLACE_ID` (default: `EBAY_US`).

Depop — Uses a headless browser to search listings with support for category, condition, size, and color filters. The browser instance is shared across requests.

Poshmark — Uses a headless browser to search listings with support for condition, size, color, sort, and price filters. Poshmark is not location-based — all items ship nationally.

Development

git clone https://github.com/jlsookiki/secondhand-mcp.git
cd secondhand-mcp
npm install
npm run build

Adding a Marketplace

1. Create a new file in `src/marketplaces/`

2. Extend `BaseMarketplace` and implement `search()` and optionally `getListingDetails()`

3. Add the constructor to `allMarketplaces` in `src/marketplaces/index.ts`

Limitations

• Facebook: May break if Facebook changes their frontend
• eBay: Requires developer API keys (free tier available)
• Depop: Requires Chrome/Chromium installed; slower than Facebook/eBay (~5s per search)
• Poshmark: Requires Chrome/Chromium installed; no official API so relies on page scraping
• Rate limiting: Don't make too many requests too quickly

License

MIT