# x402 Doctor – Batch Preflight Safety Check

> x402 Doctor – Batch Preflight Safety Check is a paid API for AI agents from x402-doctor.fizzl.eu, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-13).

Checks up to 10 x402 payment endpoints in a single call and returns a go/caution/no_go safety verdict, recommended payment option, and batch totals for each

## Facts

- Endpoint: GET https://x402-doctor.fizzl.eu/api/v1/preflight/batch?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-doctor-batch-preflight-safety-check-14d4e8a6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eY8bfGd1jq_pF7L8NCrxk

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-doctor-batch-preflight-safety-check-14d4e8a6
```

Example prompt: Before my agent pays any of these services, can you batch-check whether these three x402 endpoints are safe to pay — https://api-a.example.com/data, https://api-b.example.com/search, and https://api-c.example.com/chat — using GET, with a max budget of $0.10 per call, and give me a go/caution/no_go verdict plus the recommended payment option for each?

## When to prefer this

Use this endpoint when you need to evaluate multiple x402 payment endpoints simultaneously before committing any funds — ideal for marketplaces, agent orchestrators, or any workflow where several competing x402 services must be ranked or filtered. Prefer this over the single-URL check when you have 2–10 candidates and want batch totals and comparative verdicts in one round-trip. Choose the richer 'full diagnosis' sibling endpoint only when you need deep debugging detail on a single failing endpoint.

## Known failure modes

- URL array exceeds 10 items — request rejected
- Unreachable endpoint URLs return unknown verdict with an error field
- Invalid CAIP-2 network string may cause network-level filtering to fail
- Endpoints that return non-standard x402 headers may get caution or unknown verdicts
- Budget string malformed — may default to no budget filtering

## How this service works

Are these x402 endpoints safe to pay? Up to 10 endpoints in one call (?url=a&url=b): per endpoint go / caution / no_go, the recommended payment option and why, plus totals. For marketplaces and agents that weigh several services. Never pays the endpoints.

## Output

Returns a structured batch report containing: total count of checked endpoints; aggregate counts of go, caution, no_go, and unknown verdicts; and per-endpoint objects each with the URL, verdict enum, safe_to_pay boolean, recommended payment option index, array of reasons, and a human-readable summary. Also includes a checked_at ISO 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "array",
       "items": {
        "type": "string"
       },
       "maxItems": 10,
       "description": "The x402 endpoints to check, one url parameter each (?url=a&url=b), at most 10."
      },
      "method": {
       "enum": [
        "GET",
        "POST"
       ],
       "type": "string",
       "description": "HTTP method you will call them with. Default: try GET, then POST."
      },
      "max_usd": {
       "type": "string",
       "description": "Your budget per call in USD; above it the verdict is no_go."
      },
      "network": {
       "type": "string",
       "description": "CAIP-2 network you want to pay on."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "count",
      "counts",
      "results"
     ],
     "properties": {
      "count": {
       "type": "integer"
      },
      "counts": {
       "type": "object",
       "properties": {
        "go": {
         "type": "integer"
        },
        "no_go": {
         "type": "integer"
        },
        "caution": {
         "type": "integer"
        },
        "unknown": {
         "type": "integer"
        }
       }
      },
      "results": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "url",
         "verdict",
         "safe_to_pay",
         "summary"
        ],
        "properties": {
         "url": {
          "type": "string"
         },
         "error": {
          "type": "string"
         },
         "options": {
          "type": "array"
         },
         "reasons": {
          "type": "array"
         },
         "summary": {
          "type": "string"
         },
         "verdict": {
          "enum": [
           "go",
           "caution",
           "no_go",
           "unknown"
          ],
       
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-doctor-batch-preflight-safety-check-14d4e8a6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-doctor.fizzl.eu](https://www.zero.xyz/host/x402-doctor.fizzl.eu/llms.txt)