# x402 Preflight

> x402 Preflight is a paid API for AI agents from dznviqumoishbyp7dtbwld5444.srv.us, paid per call via x402, $0.004/call, status down (last checked 2026-10-20).

Probes an x402 payment-gated endpoint without paying to return a preflight report revealing its payment requirements and any mismatches with expected parameters.

## Facts

- Endpoint: POST https://dznviqumoishbyp7dtbwld5444.srv.us/preflight?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: down
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-preflight-f9b0018f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VoLxCSkQWjgBs2HzKxQMy

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-preflight-f9b0018f -d '<json body>'
```

Example prompt: Before I pay anything, probe the x402 endpoint at https://api.example.com/data to check its payment requirements — I'm expecting it to pay to 0xAbC...123 on base with a max of 1000000 USDC base units.

## When to prefer this

Use this endpoint whenever an agent or developer needs to verify the payment parameters of an x402-gated API before committing funds. It is the right choice when you want to confirm pay_to address, network, and price without spending USDC, or when you need to detect fraudulent or misconfigured payment details. Prefer it over directly calling the paid endpoint when trust in the payment recipient has not been established, or when budget validation is required before automated payment.

## Known failure modes

- Target URL is not reachable or returns non-402 status — report indicates endpoint is not a valid x402 resource
- pay_to address in the response differs from the expected value — report flags this as a blocking finding
- network mismatch between actual and expected — blocking finding returned
- Endpoint returns a malformed x402 payment header — report may be incomplete or error out
- Non-HTTPS URL provided — rejected before probing
- Preflight service itself is unreachable — HTTP error returned

## How this service works

One unpaid-probe preflight report for an x402 endpoint.

## Output

A preflight report describing the x402 endpoint's declared payment requirements (recipient address, network, price), plus any blocking findings such as pay_to mismatches, unexpected networks, or prices exceeding the specified ceiling — all gathered without making a payment.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "The x402 endpoint to probe (unpaid). Must be https."
  },
  "expect": {
   "type": "object",
   "properties": {
    "pay_to": {
     "type": "string",
     "description": "Recipient address you were promised; mismatch is a blocking finding."
    },
    "network": {
     "type": "string",
     "description": "Network you intend to pay on, e.g. base or eip155:8453."
    },
    "max_amount": {
     "type": "string",
     "description": "Price ceiling in base units (USDC has 6 decimals)."
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-preflight-f9b0018f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dznviqumoishbyp7dtbwld5444.srv.us](https://www.zero.xyz/host/dznviqumoishbyp7dtbwld5444.srv.us/llms.txt)