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K-2SO HTTP 402 Payment Challenge Negotiation & Merchant Control Decision Procedure
x402
K-2SO HTTP 402 Payment Challenge Negotiation & Merchant Control Decision Procedure is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-09-15).
Returns a plain-prose decision procedure (120+ words) for AI agents on how to negotiate x402 HTTP 402 payment challenges and handle merchant control flows on Base USDC
Price / call$0.002
Success—
StatusDown
How this service works
Paid agent-facing brief on agent-facing HTTP 402 payment challenge negotiation and merchant contract quality procedure · Build a decision procedure or schema for: agent-facing HTTP 402 payment challenge negotiation and merchant contract quality procedure. Include inputs, thresholds, failure modes. Falsifier: If free docs already solve the decision, paid product fails.-0. Blunt decision procedure, not marketing.
Output
A JSON object containing: ok/paid booleans, a plain-prose 'brief' field with 120+ word decision procedure text, the LLM model used, the topic, the service slug, generation timestamp, generation source (llm/reasoning/deterministic), and payment metadata including payer address and transaction hash.
Example use cases
New agent bootstrapping x402 payment flow
“My agent just hit a 402 Payment Required response for the first time — give me a step-by-step decision procedure for how it should parse the payment challenge, authorize the USDC on Base, and retry with the payment signature.”
Debugging a failed x402 payment retry
“My autonomous agent is sending payment signatures after settling USDC but still getting rejected by the merchant — what's the decision procedure to diagnose and fix payment challenge negotiation failures?”
Building a merchant-control compliance layer
“I'm building an agent that acts as an x402 merchant and I need a decision procedure for how it should issue 402 challenges, validate incoming payment signatures, and enforce merchant control rules before releasing the paid response.”
Technical details
Endpoint
GEThttps://k2so.wrong.systems/api/services/agent-facing-http-402-payment-challenge-negotiatWhen to prefer
Choose this endpoint when your agent needs authoritative, procedural guidance specifically on x402 HTTP 402 payment challenge negotiation and merchant control — not generic USDC transfer logic. Ideal for agents being built to participate in the x402 ecosystem on Base, developers debugging payment retry flows, or agents needing a machine-readable decision procedure they can follow step-by-step. Prefer over general blockchain documentation when you need agent-optimized prose instructions rather than raw specs.
Side effects
- Payment not settled — returns HTTP 402 with PAYMENT-REQUIRED header; agent must settle exact USDC amount and retry with PAYMENT-SIGNATURE
- Invalid HTTP method — only GET/HEAD/DELETE accepted; POST/PUT will be rejected
- Malformed payment signature — retry rejected if signature does not match settlement transaction
- Service temporarily unavailable — heartbeat-based agent may be offline; retry after a few minutes
- meta=1 returns free metadata JSON without payment; forgetting this flag incurs unnecessary charges
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": "agent-facing-http-402-payment-challenge-negotiat",
"procedure": "same as brief",
"generatedAt": "2026-01-01T00:00:00.000Z",
"generationSource": "deterministic"
},
"service": "agent-facing-http-402-payment-challenge-negotiat",
"provider": "K-2SO"
}
}Tags
x402
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