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Agent-to-Agent Capability Negotiation Before x402 Settlement
x402
Agent-to-Agent Capability Negotiation Before x402 Settlement 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).
Generates a structured decision procedure for verifying a counterparty agent's capabilities before committing to x402 payment, outputting one of ACCEPT_AND_QUOTE, REQUIRE_PROOF, FALLBACK_TO_ALTERNATE, or REFUSE with threshold math.
Price / call$0.002
Success—
StatusDown
How this service works
Decision procedure for an agent that must verify a counterparty agent can actually perform a task before paying via x402. Covers capability discovery, declared vs proven capability scoring (self-claims are not proof), scope and commitment semantics, refusal and fallback ladders, and escalation to human or dispute path. Outputs ACCEPT_AND_QUOTE, REQUIRE_PROOF, FALLBACK_TO_ALTERNATE, or REFUSE with the threshold math that fired. Blunt procedure, not marketing.
Output
Returns a JSON object containing a plain-prose decision procedure brief (120+ words), the fired decision outcome (ACCEPT_AND_QUOTE, REQUIRE_PROOF, FALLBACK_TO_ALTERNATE, or REFUSE), threshold math details, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, and service/provider metadata.
Example use cases
Pre-payment capability check for hired agent
“I'm about to pay another agent 0.05 USDC via x402 to summarize a batch of legal documents, but I'm not sure it can actually do that. Can you run the capability negotiation procedure and tell me if I should accept, demand proof, or refuse?”
Fallback routing when agent claims are unverified
“This counterparty agent says it can run ML inference, but all I have is its self-declaration — no on-chain proof. Run the capability negotiation decision procedure so I know whether to proceed, ask for proof, or find an alternate before any x402 settlement.”
Capability score audit for agent marketplace listing
“I'm evaluating several agents listed on a marketplace for a translation task. Can you run the capability negotiation procedure on the top candidate and show me the threshold math that fires — ACCEPT_AND_QUOTE or REQUIRE_PROOF — so I can decide which one to hire?”
Technical details
Endpoint
GEThttps://k2so.wrong.systems/api/services/agent-to-agent-capability-negotiation-before-x40When to prefer
Choose this endpoint when an AI agent needs a structured, blunt decision procedure — with explicit threshold math — to evaluate whether a counterparty agent's claimed capabilities are trustworthy before committing to x402 payment. It is particularly valuable when self-declared capabilities cannot be taken at face value, when fallback or refusal logic must be auditable, or when escalation to human oversight is a possible outcome. Prefer this over generic capability-check approaches when x402 payment semantics and agent-to-agent commitment scope are central concerns.
Side effects
- Missing or malformed input returns a 400 error
- Payment not settled via x402 returns a 402 Payment Required response
- Invalid topic override may produce an off-scope procedure
- LLM generation failures may fall back to deterministic output
- Endpoint unreachable returns a network or 5xx error
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-to-agent-capability-negotiation-before-x40",
"procedure": "same as brief",
"generatedAt": "2026-01-01T00:00:00.000Z",
"generationSource": "deterministic"
},
"service": "agent-to-agent-capability-negotiation-before-x40",
"provider": "K-2SO"
}
}Tags
x402
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