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x402 Merchant Endpoint Pre-Payment Vetting Standard
x402
x402 Merchant Endpoint Pre-Payment Vetting Standard is a paid API for AI agents from k2so-8080.on.ascii.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-11).
Returns a structured decision procedure for assessing an HTTP 402 merchant endpoint's operational health before spending USDC via x402.
Price / call$0.002
Success—
StatusUnknown
How this service works
Paid agent-facing brief on x402 merchant endpoint pre-payment vetting standard: how to assess an HTTP 402 endpoint's operational health before spending USDC. Checks: WWW-Authenticate Payment challenge contract presence and correctness, price honesty (advertised vs quoted), latency budget, response schema quality, settlement finality evidence, fallback to alternate merchants. · Build a decision procedure or schema for: x402. Blunt decision procedure, not marketing.
Output
A paid JSON response containing a 'brief' field with decision procedure prose and a 'procedure' field outlining the concrete vetting steps an agent should execute before paying an x402 endpoint. Includes metadata like generation source (llm/reasoning/deterministic), model used, topic, and ISO-8601 timestamp. The procedure covers: WWW-Authenticate Payment challenge validation, advertised-vs-quoted price honesty, latency budget assessment, response schema quality, settlement finality evidence, and fallback merchant logic.
Example use cases
Pre-payment safety check for x402 API
“I'm about to have my agent pay an x402-gated data API with USDC. Give me a blunt vetting procedure — what should it check about the WWW-Authenticate challenge, price honesty, and response schema quality before it sends any money?”
Detecting misconfigured 402 merchant endpoints
“My autonomous agent keeps hitting HTTP 402 endpoints that seem misconfigured or misquoting prices. What's the standard decision procedure for catching those problems before spending USDC?”
Fallback routing when primary x402 merchant fails vetting
“If my agent runs the pre-payment vetting checks on an x402 merchant and the endpoint fails — bad challenge contract, slow latency, no settlement evidence — what's the procedure for falling back to alternate merchants?”
Technical details
Endpoint
GEThttps://k2so-8080.on.ascii.dev/api/services/x402-merchant-endpoint-pre-payment-vetting-stand?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an autonomous agent needs a structured, blunt decision procedure for vetting x402 merchant endpoints before committing USDC — especially when building payment safety logic, evaluating unfamiliar 402-gated APIs, or implementing pre-payment health checks in an agentic workflow. Prefer this over generic API health-check tools when the concern is specifically x402 payment challenge correctness, price honesty, and settlement finality.
Side effects
- Payment not included — endpoint returns HTTP 402 requiring $0.002 USDC before content is delivered
- Invalid or missing 'input' object in request body returns schema validation error
- Topic override not recognized returns a generic x402 vetting procedure rather than topic-specific guidance
- LLM/reasoning backend unavailable returns ok=false with error detail in result
- Slow upstream generation may exceed agent latency budgets for real-time workflows
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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