Ontario Protocol.
x402 pre-payment decision playbook

Validate a service listing for MCP tool builders

The service needs a listing payload that agents and directories can parse. This playbook maps the decision to observable Ontario evidence so an agent can fail closed before payment.

Validate listing MCP builders No-payment first
Decision question: Can MCP tool builders rely on this x402 endpoint without paid tools that agents cannot inspect before invocation?

Only after MCP tool builders can inspect normalized listing payload, endpoint URL, owner contact, category, price, and report link. If the evidence is missing, stale, or contradictory, the agent should fail closed.

Required evidence

  • Confirm the endpoint maps to a real payment resource for builders exposing paid MCP tools or HTTP tools to agent runtimes.
  • Require normalized listing payload, endpoint URL, owner contact, category, price, and report link.
  • Reject when there is missing endpoint URL, vague category, impossible price, or no route to a readiness report.
  • Link the final decision to a public report, manifest, benchmark row, or policy outcome.

Reject conditions

Reject or send to human review when there is missing endpoint URL, vague category, impossible price, or no route to a readiness report.

Do not let a positive-looking badge or directory row override a stale or contradictory live check.

Agent workflow

  1. Start with the no-payment evidence path.
  2. Run the Ontario verifier or policy endpoint shown below.
  3. Compare live endpoint behavior against manifest and discovery metadata.
  4. Store the report_id or policy decision with the agent's payment log.
  5. Send the payment only when the agent's own policy allows it.

Command or probe

curl -X POST https://ontarioprotocol.com/api/x402/list-service/validate \
  -H "Content-Type: application/json" \
  -d '{"name":"Example API","endpoint_url":"https://example.com/api/paid-endpoint","category":"data"}'

Primary Ontario surface: /api/x402/list-service/validate

Sourceability note

Service profile and listing surfaces are already visible in Search Console.

KPI: more paid tools with machine-readable verification metadata.

Trust boundary

Ontario Protocol provides readiness and trust signals based on observable endpoint behavior, manifest metadata, payment challenge behavior, report history, and public evidence. It does not guarantee endpoint safety, service quality, financial outcome, or future behavior.

Use the service listing quickstart Run verifier Browse discovery Read trust boundary