# x402 Seller Mini-Check (gpt55.558686.xyz)

> x402 Seller Mini-Check (gpt55.558686.xyz) is a paid API for AI agents from gpt55.558686.xyz, paid per call via x402, $0.006/call, status down (last checked 2026-10-13).

Returns a quick competitor price and directory positioning snapshot for x402 and paid MCP sellers before purchasing a full growth plan.

## Facts

- Endpoint: POST https://gpt55.558686.xyz/v1/paid/x402-seller-mini-check?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: down
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-seller-mini-check-gpt55-558686-xyz-6f757f1e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4pNvgsCrBFJJiMMxXF20C

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-seller-mini-check-gpt55-558686-xyz-6f757f1e -d '<json body>'
```

Example prompt: Can you run a quick x402 seller mini-check for the query 'GPT chat completions' across sources like 402index, x402.direct, and payai-discovery — limit to 20 results per page — so I can see how my listing compares before I buy the full growth plan?

## When to prefer this

Use this endpoint when you need a fast, low-cost ($0.006) pre-purchase benchmark for x402 or paid MCP seller directory positioning, especially when you want to probe multiple x402 discovery sources simultaneously before committing to a full growth plan. Prefer this over broader market research tools when your specific concern is x402 protocol marketplace placement and competitor pricing.

## Known failure modes

- Query string missing or empty — returns validation error
- Timeout exceeded (timeout_ms too low for multi-source queries) — partial or empty results
- Invalid source name in sources array — rejected by schema validation
- Payment not fulfilled via x402 USDC on Base — 402 Payment Required response
- pages or limit out of allowed range — schema validation error

## Output

Returns a snapshot object with ok status, tool identifier, fetchedAt timestamp, and market benchmark data showing competitor pricing and directory positioning for x402 sellers.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "query"
     ],
     "properties": {
      "limit": {
       "type": "integer",
       "maximum": 100,
       "minimum": 1
      },
      "pages": {
       "type": "integer",
       "maximum": 3,
       "minimum": 1
      },
      "query": {
       "type": "string",
       "maxLength": 120,
       "minLength": 1
      },
      "sources": {
       "type": "array",
       "items": {
        "enum": [
         "402index",
         "x402.direct",
         "x402scout",
         "cinderwright",
         "pay-sh",
         "cdp-bazaar",
         "agora402",
         "x402-list",
         "a2alist",
         "payai-discovery",
         "gate402"
        ],
        "type": "string"
       },
       "maxItems": 10
      },
      "page_size": {
       "type": "integer",
       "maximum": 100,
       "minimum": 10
      },
      "timeout_ms": {
       "type": "integer",
       "maximum": 15000,
       "minimum": 1000
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "tool": {
       "type": "string"
      },
      "fetchedAt": {
       "type": "string"
      }
     },
     "additionalProperties": true
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-seller-mini-check-gpt55-558686-xyz-6f757f1e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gpt55.558686.xyz](https://www.zero.xyz/host/gpt55.558686.xyz/llms.txt)