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K-2SO x402 Merchant Endpoint Pre-Payment Vetting Standard
x402
K-2SO x402 Merchant Endpoint Pre-Payment Vetting Standard is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).
Returns an AI-generated decision procedure (prose brief) for how an agent should assess and vet a paid x402 merchant endpoint before committing payment
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 JSON object containing: a boolean success flag, a 'paid' confirmation, the service slug, provider name ('K-2SO'), and a result object with a plain-prose 'brief' (120+ words) laying out the decision procedure for pre-payment vetting, plus metadata: the LLM model used, topic, ISO-8601 generation timestamp, and generation source (llm/reasoning/deterministic).
Example use cases
Agent wallet spend-control gate
“My autonomous agent is about to pay $0.002 USDC for an x402 market-data API — can you pull the pre-payment vetting brief from K-2SO so I can review whether it's safe to approve the charge?”
Onboarding new x402 service providers
“We're building an agent that discovers new x402 services on Base — get me the vetting decision procedure so the agent knows what criteria to check before it pays any new merchant endpoint for the first time.”
Compliance review before autonomous spending
“Our agent fleet is allowed to autonomously call paid APIs, but I need a documented vetting standard — fetch the K-2SO pre-payment vetting procedure brief for the x402-merchant-endpoint-pre-payment-vetting-stand service so we can embed it in our agent's decision logic.”
Technical details
Endpoint
GEThttps://k2so.wrong.systems/api/services/x402-merchant-endpoint-pre-payment-vetting-standWhen to prefer
Choose this endpoint when an autonomous agent needs a structured, AI-generated prose brief for deciding whether and how to vet an x402 merchant endpoint before settling USDC payment — especially useful when bootstrapping agent spend-control logic, auditing new x402 merchants, or embedding a reusable decision procedure in an agent's approval workflow. Prefer this over generic LLM prompting when you want a consistent, K-2SO-authoritative vetting standard with structured output and a timestamp.
Side effects
- HTTP 402 returned if payment not yet settled — agent must pay exact USDC amount and retry with PAYMENT-SIGNATURE header
- Invalid method (POST, PUT, PATCH) returns error — only GET/HEAD/DELETE supported
- Malformed queryParams (e.g. invalid 'meta' enum value) may result in 400 error
- Network or upstream LLM failure may return ok:false with empty brief
- Payment signature mismatch or expired payment may cause 402 retry loop
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"paid": true,
"result": {
"ok": true,
"brief": "plain prose decision procedure (120+ words)",
"model": "deepseek/deepseek-v4-flash-0731",
"topic": "string topic",
"service": "x402-merchant-endpoint-pre-payment-vetting-stand",
"procedure": "same as brief",
"generatedAt": "2026-01-01T00:00:00.000Z",
"generationSource": "deterministic"
},
"service": "x402-merchant-endpoint-pre-payment-vetting-stand",
"provider": "K-2SO"
}
}Tags
x402
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