# K-2SO x402 Static File Serving Standard Merchant Decision Procedure

> K-2SO x402 Static File Serving Standard Merchant 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 2026-10-18).

Returns a paid AI-agent-facing decision procedure brief on standard static file serving via the x402 micropayment protocol on Base USDC

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/x402-static-file-serving-standard-merchant?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/k-2so-x402-static-file-serving-standard-merchant-decision-procedure-34a8ca4d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bfQF11luj6XnGEeDYBj0m

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 k-2so-x402-static-file-serving-standard-merchant-decision-procedure-34a8ca4d
```

Example prompt: I need a decision procedure brief explaining how an autonomous agent should handle x402 static file serving — get me the standard merchant guidance as a plain prose summary I can act on.

## When to prefer this

Choose this endpoint when an AI agent needs structured, prose-format guidance on how to handle x402 static file serving interactions — especially when building or auditing agent payment flows on Base USDC. Prefer it over generic documentation when you need an agent-consumable brief that can be directly acted upon in an agentic decision loop. It is particularly useful for bootstrapping new agents that need to learn the x402 static file merchant pattern without human-written documentation.

## Known failure modes

- HTTP 402 returned if payment not yet settled — agent must complete USDC payment and retry with PAYMENT-SIGNATURE header
- Invalid or missing HTTP method enum value causes schema validation failure
- Free metadata (meta=1) returns service description without decision prose — not a full brief
- Network or upstream LLM failure may result in empty or incomplete brief field
- Incorrect topic override may yield off-target decision procedure prose

## How this service works

Merchant-side deterministic standard for serving static digital files behind HTTP 402 micropayment. Covers pre-payment metadata exposure with content hash, byte size, MIME type, and license, range-request handling for partial content, re-download idempotency keyed on settlement receipt, ETag and cache semantics to prevent re-charging paid content, post-settlement hash receipt attestation, and revocation rules for recalled artifacts. One verdict per file.

## Output

A JSON object containing a plain-prose decision procedure brief (120+ words) tailored for AI agents, including the service slug, generation source (llm, reasoning, or deterministic), the model used, a topic label, an ISO-8601 generation timestamp, and provider attribution from K-2SO. Returned only after a valid USDC micropayment (~$0.002) is settled via x402 on Base.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "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": "x402-static-file-serving-standard-merchant",
   "procedure": "same as brief",
   "generatedAt": "2026-01-01T00:00:00.000Z",
   "generationSource": "deterministic"
  },
  "service": "x402-static-file-serving-standard-merchant",
  "provider": "K-2SO"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/k-2so-x402-static-file-serving-standard-merchant-decision-procedure-34a8ca4d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so.wrong.systems](https://www.zero.xyz/host/k2so.wrong.systems/llms.txt)