# x402 No-Payment-Terms Decision Procedure

> x402 No-Payment-Terms Decision 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 2026-10-15).

Returns an agent-facing decision procedure for handling x402 endpoints that return no payment terms (no 402 challenge, HTTP 404/405, or weak merchant contract).

## Facts

- Endpoint: GET https://k2so-8080.on.ascii.dev/api/services/agent-facing-decision-procedure-for-x402-endpoin?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-no-payment-terms-decision-procedure-63182735
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JN-oPwjvQSm-2hUr-hGP3

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 x402-no-payment-terms-decision-procedure-63182735
```

Example prompt: My agent hit an x402 endpoint with a GET request and got no 402 challenge back — just a 404. What's the decision procedure: should I probe again, back off, try an alternate rail, or kill the request entirely?

## When to prefer this

Choose this endpoint when your agent has encountered an x402 endpoint that did not return a standard 402 payment challenge — specifically when you need a structured, agent-optimized decision procedure covering probe logic, retry/backoff thresholds, alternate rail fallback, and kill criteria. Prefer this over generic x402 documentation when you need a single actionable verdict rather than reference material.

## Known failure modes

- Endpoint returns HTTP 404 if the service slug or path is wrong
- Payment not processed correctly results in unpaid response without procedure content
- LLM generation failure may result in ok:false with no brief
- Invalid method (non-GET/HEAD/DELETE) rejected by schema validation
- Malformed input object causes request rejection

## How this service works

Decision procedure for when an x402 endpoint returns no payment terms: no 402 challenge, HTTP 404/405, or a weak merchant contract. Covers probe interpretation, knock-or-backoff thresholds, alternate rail fallback, retry budgets, and kill criteria, ending in a single verdict.

## Output

A structured response containing decision procedure prose (brief) tailored for AI agents, covering probe interpretation, knock-or-backoff thresholds, alternate rail fallback strategies, retry budgets, and kill criteria — ending in a single actionable verdict. Also includes metadata like model used, topic, generation source, and timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "agent-facing decision procedure for x402 endpoints that return no payment terms paid response",
     "$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": {

… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-no-payment-terms-decision-procedure-63182735/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)