Bunjang MCP

An MCP server for searching public listings on Bunjang, running as a Cloudflare Worker behind the Common Auth gateway.

Tools

• bunjang_search: returns matching listings and an average, highest, and lowest asking price for the returned listings.

The tool returns listing URLs, prices, sale status, seller and engagement metadata, seller descriptions, and original-size product image URLs. Set include_details=false to skip one detail request per returned listing when speed matters more than descriptions and full images.

Results default to 20 listings. To continue, pass the returned next_offset as the next call's offset. has_more says whether more listings are available. The service handles Bunjang's internal cursor pagination, crosses its 60-entry upstream page boundaries, and removes repeated promoted products. Since marketplace results change over time, consecutive pages are not a permanent snapshot.

The summary describes current asking prices among the listings returned by that call. It is not a sold-price history. External shopping ads are excluded from listings and price calculations. max_listings is limited to 60 per call.

There is no cache. Module-level state does not reliably persist between Worker requests, so every call fetches fresh data from Bunjang.

Detail-enriched calls (include_details=true) make one upstream request per listing, up to eight at a time. Any of those can fail (a Bunjang error, a timeout, or a Workers subrequest limit); the listing is still returned with its search-page fields only, and detail_failures in the result counts how many came back that way. A partial result is reported, never hidden.

Related MCP server: Mercari MCP Server

Usage

{
  "mcpServers": {
    "bunjang": {
      "type": "remote",
      "url": "https://bunjang.lost.plus/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_TOKEN"
      }
    }
  }
}

Send a Common Auth token as Authorization: Bearer <token> or X-API-Key: <token> (scope bunjang). Machine tokens and OAuth access tokens are both accepted. Clients speaking MCP 2026-07-28, 2025-06-18 and 2025-03-26 are all served; 2026-07-28 clients are told to cache the tool list for five minutes.

How it is reached

client -> bunjang.lost.plus/mcp -> auth-gateway Worker -> [BUNJANG service binding] -> this Worker

• Routes. This Worker holds none (wrangler.toml has no routes, workers_dev = false). bunjang.lost.plus/mcp, /mcp/*, /healthz and /.well-known/oauth-protected-resource* are zone routes on the auth-gateway Worker (auth/gateway/wrangler.toml).

• Auth. The gateway's route table (auth/gateway/config/cloudflare.gateway.json) has {"host": "bunjang.lost.plus", "policy": "mcp", "token_scope": "bunjang", "binding": "BUNJANG"}. The gateway validates the credential with the hub, strips it, and forwards over the BUNJANG service binding with the caller in x-lost-plus-{sub,email,name,role,encoding} headers. This Worker reads those with the shared @lpfchan/gateway-identity package and never sees a token. A request without a complete identity is refused with 500, because nothing but the gateway can reach this Worker and such a request means the deployment is wrong.

• Gateway-answered paths. /healthz returns ok as text/plain; /.well-known/oauth-protected-resource/mcp is the OAuth metadata document; a bad or missing token gets a 401 with a WWW-Authenticate challenge. None of those reach this Worker, which serves /mcp (and /mcp/) only.

• State. None. No D1, KV or R2; everything is plain [vars].

Deploy

npm install
npm run typecheck   # tsc --noEmit
npm test            # vitest
npm run deploy      # passage run --env CLOUDFLARE_API_TOKEN=infra/CF_MASTER_TOKEN -- wrangler deploy

The deploy token comes from passage at deploy time (infra / CF_MASTER_TOKEN, through the passage setup module); an already-exported CLOUDFLARE_API_TOKEN wins if one is set.

Deploying only replaces this Worker's code; routes live on the gateway and are untouched. To roll back, git revert (or check out the previous commit) and npm run deploy again. Adding a route to this Worker's wrangler.toml would steal it from the gateway and expose an unauthenticated entrance; see the comment there.

No secrets are required. Configuration:

History

Until 2026-09-18 this ran as a Python container (python/, FastMCP, port 8004 on oci-ubuntu behind the Cloudflare tunnel and the local Rust gateway). The Worker port replaced it; python/ was removed on 2026-09-19 once its tests were ported to test/. The Python server's in-memory cache, force_refresh argument and from_cache field did not survive the port.