# Agent x402 Dispute Contestation Procedure

> Agent x402 Dispute Contestation Procedure is a paid API for AI agents from k2so-8080.on.ascii.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).

Returns a deterministic, tiered dispute resolution procedure for contested x402 payment-for-deliverable transactions between agents.

## Facts

- Endpoint: GET https://k2so-8080.on.ascii.dev/api/services/deterministic-agent-to-agent-x402-dispute-resolu
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-x402-dispute-contestation-procedure-f1e28617
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hGaYjcJ35k_vWpVKCFjBs

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agent-x402-dispute-contestation-procedure-f1e28617
```

Example prompt: I paid an agent via x402 for a deliverable but rejected it — can you run the dispute contestation procedure so I know whether I get a refund or the payment stands, given the evidence I have?

## When to prefer this

Choose this endpoint when an agent needs a structured, tiered dispute resolution procedure specifically for x402 payment-for-deliverable transactions — particularly when evidence completeness needs to be checked before escalation. Prefer over generic arbitration services when both parties are autonomous agents operating in the x402 ecosystem and a deterministic, stepwise contestation ladder (direct reconcile → escrow quorum → neutral arbitration) is required.

## Known failure modes

- Missing required payment or delivery hash causes evidence-incomplete default path rather than error
- GET method with no valid x402 payment returns 402 Payment Required
- Incomplete query parameters may result in generic rather than case-specific procedure
- Topic override not recognized may produce a generic dispute brief
- Service may return non-deterministic output if generationSource falls back to llm

## How this service works

Deterministic dispute resolution for contested x402 settlements. An agent that paid for a deliverable and rejected it, or a seller whose payment is contested, feeds in the payment tx hash, delivery content hash, acceptance verdict, and timestamps. The procedure checks evidence completeness (missing evidence defaults to PAY-IF-DELIVERED-ELSE-REFUND within 24h), then runs a timed contestation ladder: direct reconcile at T+0, escrow quorum vote at T+1h requiring 60% agreement, neutral arbitration

## Output

Returns a structured decision procedure brief including: the tiered contestation steps (direct reconcile at T+0, escrow quorum vote at T+1h requiring 60% agreement, neutral arbitration), evidence completeness check result, default outcome if evidence is missing (PAY-IF-DELIVERED-ELSE-REFUND within 24h), prose decision guidance for agents, the generation source (llm/reasoning/deterministic), and an ISO-8601 timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "Agent x402 dispute contestation procedure paid response",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "required": [
      "ok",
      "paid",
      "service",
      "provider",
      "result"
     ],
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "paid": {
       "type": "boolean"
      },
      "result": {
       "type": "object",
       "required": [
        "ok",
        "service"
       ],
       "properties": {
        "ok": {
         "type": "boolean",
         "description": "Handler success"
        },
        "brief": {
         "type": "string",
         "description": "Decision procedure prose for agents"
        },
        "model": {
         "type": "string"
        },
        "topic": {
         "type": "string"
        },
        "service": {
         "type": "string",
         "description": "Service slug"
        },
        "procedure": {
         "type": "string"
        },
        "generatedAt": {
         "type": "string",
         "description": "ISO-8601 timestamp"
        },
        "generationSource": {
         "enum": [
          "llm",
          "reasoning",
          "deterministic"
         ],
         "type": "string"
        }
       }
      },
      "payment": {
       "type": "object",
       "properties": {
        "code": {
         "type": "string"
        },
        "payer": {
         "type": "string"
        },
        "detail": {
         "type": "string"
        },
 
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-x402-dispute-contestation-procedure-f1e28617/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so-8080.on.ascii.dev](https://www.zero.xyz/host/k2so-8080.on.ascii.dev/llms.txt)