Zero as an MCP server
Zero's official MCP server at https://mcp.zero.xyz gives any MCP client search over 109,591 pay-per-call services, the facts on each (price, rail, live status, real usage), and the ability to call and pay for one over x402 or MPP from the user's Zero balance, with no API key per service. Sign-in is OAuth; the connector exposes 9 tools.
Tools
search_capabilities, get_capability, invoke_capability, review_capability, get_profile, get_funding_url, upload_file, request_file_from_user, authorize.
search_capabilities and get_capability are read-only. invoke_capability calls a service and pays for it within the caps the user set; review_capability records a rating after a run; get_funding_url returns where to add balance; upload_file and request_file_from_user move files into and out of a call.
Connect
Add https://mcp.zero.xyz as a remote MCP server in your client and sign in when prompted. Clients that support OAuth discovery find the authorization server from https://mcp.zero.xyz/.well-known/oauth-protected-resource.
For a terminal agent, the CLI does the same without MCP:
npm i -g @zeroxyz/cli
zero init
zero auth login
How an agent uses one
An agent searches Zero for the need, gets the ranked services with price, rail and live status, and calls one. Zero answers the service's payment challenge (an HTTP 402 with an x402 or MPP demand), pays from the agent's Zero balance, retries the request with the payment proof, and returns the result.
Every call is recorded as a run, so the service's success rate, price actually charged and last successful call are real numbers on its page, not claims.
Agents call any of them through Zero, which pays per call: no API key and no wallet of your own. New accounts start with $5.