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Multi-rail x402 Payment Flow Protocol Classification Procedure
x402
Multi-rail x402 Payment Flow Protocol Classification Procedure is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-10-18).
Returns a decision procedure for identifying which x402 payment flow protocol an unfamiliar paid endpoint speaks and what steps are required to pay it
Price / call$0.002
Success—
StatusDown
How this service works
Decision procedure for an agent that hits an unfamiliar paid endpoint and must identify which payment flow it speaks before paying. Classifies Base x402 challenge (WWW-Authenticate Payment, eip155: 8453, USDC), Solana CIRC Token-2022 quote-transfer-resend flow, MPP Tempo gateway challenge, and gateway-wrapper endpoints (which hide a flow behind another host). Returns protocol id, required headers, token/network, resend semantics, single-use flag, and the exact ordered steps to settle. Includes
Output
A structured JSON response containing a prose decision procedure (brief field) describing how to classify x402 payment flow protocols across rails (Base x402 challenge, Solana CIRC Token-2022 quote-transfer-resend, MPP Tempo challenge, gateway wrapper), along with the topic, service slug, generation source (llm/reasoning/deterministic), and ISO-8601 timestamp of generation.
Example use cases
Identifying unknown 402 endpoint payment flow
“My agent just got a 402 response from an endpoint I've never seen before and I have no idea if it's Base x402, Solana CIRC Token-2022, or something else — can you give me the step-by-step decision procedure to figure out which payment protocol it's using?”
Building an autonomous agent payment router
“I'm building an autonomous agent that needs to pay across multiple rails and I need a blunt classification schema so it can detect whether a new endpoint uses Base x402 challenge, MPP Tempo challenge, or a gateway wrapper before attempting payment — fetch me that decision procedure.”
Debugging a failed multi-rail payment attempt
“My agent tried to pay an endpoint and failed because it guessed the wrong x402 flow — can you pull the protocol classification procedure so I can work out whether it should have used Base x402 challenge, Solana CIRC quote-transfer-resend, or a gateway wrapper path?”
Technical details
Endpoint
GEThttps://k2so.wrong.systems/api/services/multi-rail-x402-payment-flow-protocol-classifica?utm_source=zero.xyzWhen to prefer
Use this endpoint when an AI agent encounters an unfamiliar paid endpoint returning a 402 and needs to programmatically determine which x402 payment flow protocol it implements before attempting payment. Prefer this over generic documentation searches when you need a blunt, agent-executable decision procedure specifically covering Base x402 challenge, Solana CIRC Token-2022, MPP Tempo challenge, and gateway wrapper flows in a single authoritative brief.
Side effects
- Payment not completed — endpoint returns 402 challenge requiring $0.002 USDC before content is delivered
- Invalid method — only GET/HEAD/DELETE accepted
- Upstream LLM generation failure — result.ok may be false with no brief returned
- Topic override produces out-of-scope result if topic param is unrelated to x402 flows
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": "multi-rail-x402-payment-flow-protocol-classifica",
"procedure": "same as brief",
"generatedAt": "2026-01-01T00:00:00.000Z",
"generationSource": "deterministic"
},
"service": "multi-rail-x402-payment-flow-protocol-classifica",
"provider": "K-2SO"
}
}Tags
x402
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