x402 Bazaar Listing Monitor

Scheduled watchdog for x402 sellers: polls Coinbase CDP's public Bazaar discovery catalog for your registered resources and payTo address, flagging a drop or…

CommunityDegradedNo sign-inGlobalFreeRead-only

What it can do

  • Check Listing Health: Checks whether a seller's x402 Bazaar resources are currently listed under the given payTo address in the public discovery catalog. Flags each resource as listed, missing, or pay

What data it sees

Do you need an account

No: the server works without sign-in

Scheduled watchdog for x402 sellers: polls Coinbase CDP's public Bazaar discovery catalog for your registered resources and payTo address, flagging a drop or a recovery — instead of finding out from a revenue dip days later.

How it works: register a payTo address and resource URLs once; a scheduled poll diffs them against the live discovery catalog and alerts on a state change. The check_listing_health MCP tool runs the same scoped diff on demand, whether or not a payTo/resources pair has been registered.

Free tier: 6-hour polling, drop/recovery detection with a durable alert history — no card required. Paid tiers tighten the polling interval and add escalation/rank-drop alert types.

Docs & changelog: https://github.com/acjlabs/x402-listing-monitor

How to connect

How to connect x402 Bazaar Listing Monitor to Claude

The server address to paste into Claude settings:

https://x402-listing-monitor--acjlabs.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect x402 Bazaar Listing Monitor to ChatGPT

The server address to paste into ChatGPT settings:

https://x402-listing-monitor--acjlabs.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect x402 Bazaar Listing Monitor to Cursor

The server address to paste into Cursor settings:

https://x402-listing-monitor--acjlabs.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (1)

Raw names from tools/list. Only developers need these.

check_listing_healthChecks whether a seller's x402 Bazaar resources are currently listed under the given payTo address in the public discovery catalog. Flags each resource as listed, missing, or payTo-mismatched — the same per-seller diff the registered poller runs on a schedule, run once on demand for a payTo/resources pair whether or not it has been registered with this service.