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Estimate-First Pre-Payment Discipline for Agents
x402
Estimate-First Pre-Payment Discipline for Agents 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).
Provides a decision procedure for AI agents to verify an x402/MPP payment challenge's price, network, expiry, and terms before paying, preventing overpayment and settlement failures.
Price / call$0.002
Success—
StatusDown
How this service works
Decision procedure for verifying an x402/MPP challenge's quoted price, network, expiry, and terms BEFORE paying: parse the 402 challenge, confirm the quote matches the agent's budget and wallet fit, detect price surprises and hidden fees, then pay or refuse with evidence. Eliminates the settlement-failure class where agents pay without checking the price first.
Output
Returns a structured decision procedure brief including: a go/no-go recommendation, prose explaining the reasoning, detection of price surprises or hidden fees, network and expiry validation status, the service slug, generation timestamp, and source (llm/reasoning/deterministic). Also includes payment metadata confirming whether the call itself was paid.
Example use cases
Budget guard before agent micropayment
“I have an x402 payment challenge from an API I want to call — it's asking for 0.005 USDC on Base — can you verify the price, network, and expiry are all legitimate and within my $0.01 per-call budget before I approve the payment?”
Hidden fee detection on third-party service
“This x402 invoice from a third-party data provider looks higher than what was advertised — run the pre-payment check and tell me if there are any hidden fees or price surprises I should know about before my agent settles.”
Automated refusal with audit trail
“My agent is about to pay an x402 challenge but I want it to always verify the terms first — run the estimate-first discipline check and if anything looks off, refuse the payment and give me the evidence so I can audit what happened.”
Technical details
Endpoint
GEThttps://k2so.wrong.systems/api/services/estimate-first-pre-payment-discipline-for-agentsWhen to prefer
Choose this endpoint when your agent needs a deterministic, evidence-backed pre-payment gate before settling any x402/MPP challenge — especially when operating autonomously with a fixed budget or when integrating with third-party services where price surprises or hidden fees are a risk. Prefer this over ad-hoc budget checks when you need a structured audit trail for refusals or when compliance with a pre-payment discipline policy is required.
Side effects
- Missing or malformed x402 challenge input returns a handler error with ok:false
- Challenge expiry already elapsed results in a refusal with expiry evidence
- Network mismatch between challenge and agent wallet causes a validation failure
- Price exceeds configured budget triggers a refuse decision with price comparison detail
- Service temporarily unavailable returns a non-200 with no result body
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": "estimate-first-pre-payment-discipline-for-agents",
"procedure": "same as brief",
"generatedAt": "2026-01-01T00:00:00.000Z",
"generationSource": "deterministic"
},
"service": "estimate-first-pre-payment-discipline-for-agents",
"provider": "K-2SO"
}
}Tags
x402
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