Agent docs

Paid per tool. No free checks. Recommended unit $0.002 (Bazaar micro-utils often $0.001–$0.005). Use before any x402 settle when you need to know is this x402 endpoint safe, verify payTo, check uptime, compare sellers, or keep a budget guard.

Single

GET https://x402check.dev/preflight?url=https%3A%2F%2Fwww.api-xpay.com%2Fx402%2Fping

Batch (N × $0.002 in one Exact payment)

POST https://x402check.dev/preflight
{"urls":["https://a.example/x402","https://b.example/x402"]}

Limitation: x402 Exact = one settlement per HTTP request. Batch uses DynamicPrice = N×unit, not N separate txs.

When to call

• Before PAYMENT-SIGNATURE / any third-party x402 settle
• Verify payTo; detect payTo or price changes
• Uptime / is the endpoint down
• Compare candidates; screen Bazaar search hits
• Validate 402 requirements; debug failing settles
• Audit log of why you paid or refused

Adopt by default

• Client wrapper that calls preflight before any x402 pay (x402check-client).
• Runtime skill/middleware default-on with env kill-switch.
• Policy: avoid→deny, caution→confirm, ok→still enforce maxAmount.
• MCP tools: preflight_check, verify_payto, preflight_batch, compare_tools.
• Keep p95 <300ms via cache so agents don’t skip.

Machine-readable

openapi.json · llms.txt · llms-full.txt · mcp.json · mcp/server-card · ai-catalog · docs.md