Ontario Protocol.
x402 pre-payment decision playbook

Check Base USDC network metadata for MCP tool builders

Network and asset drift can make an otherwise valid payment challenge unusable. This playbook maps the decision to observable Ontario evidence so an agent can fail closed before payment.

Check Base USDC 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 scheme, network, asset contract, payTo address, maxAmountRequired, and facilitator support. 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 scheme, network, asset contract, payTo address, maxAmountRequired, and facilitator support.
  • Reject when there is network mismatch, unsupported asset, missing payTo, or price fields that cannot be converted.
  • 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 network mismatch, unsupported asset, missing payTo, or price fields that cannot be converted.

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 https://ontarioprotocol.com/facilitator/supported
# Treat live supported networks/assets as the source of truth before hardcoding.

Primary Ontario surface: /facilitator/supported

Sourceability note

Search Console showed early impressions for Base versus Arbitrum comparison.

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.

Compare agent payment rails Run verifier Browse discovery Read trust boundary