# Agent Tools Preflight Checker

> Agent Tools Preflight Checker is a paid API for AI agents from agent-tools-7936.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-10).

Verifies whether an x402 payment-gated endpoint is reachable, correctly configured, and within budget before an agent commits to paying

## Facts

- Endpoint: GET https://agent-tools-7936.onrender.com/preflight?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-tools-preflight-checker-569a45cb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_h4RyBJQ1LYV8ymEusf_JH

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 agent-tools-preflight-checker-569a45cb
```

Example prompt: Before we pay anything, can you preflight check https://some-x402-api.example.com/data using GET to make sure it's a valid x402 endpoint and that the price is under $0.01?

## When to prefer this

Use this endpoint when an AI agent is about to pay for an x402-gated API call and needs to confirm the endpoint is live, correctly configured, affordable within a stated budget, and returning valid payment metadata before committing any funds. Prefer this over blindly paying when budget controls or endpoint integrity matter.

## Known failure modes

- Endpoint is unreachable — verdict may be INVALID or no response
- Endpoint does not return 402 — not a valid x402 service
- Price exceeds max_price_usd budget — verdict is OVER_BUDGET
- Malformed x402 payment header — valid field set to false in response
- Slow or timing-out upstream endpoint — high latency_s returned
- Missing required 'url' query parameter — request rejected

## How this service works

Primary-source tools for AI agents: verify before you pay, cite, or repeat.

## Output

Returns a JSON object with a verdict (e.g. PAYABLE, OVER_BUDGET, INVALID), measured latency in seconds, the HTTP status code received, and a payment_required object detailing whether the x402 header is valid, the supported networks, price in USD, and asset symbol (e.g. USDC 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",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "The x402 endpoint you are about to pay."
      },
      "method": {
       "enum": [
        "GET",
        "POST"
       ],
       "type": "string",
       "description": "HTTP method the endpoint expects."
      },
      "max_price_usd": {
       "type": "string",
       "description": "Your budget per call; over it the verdict is OVER_BUDGET."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "verdict": {
       "type": "string"
      },
      "latency_s": {
       "type": "number"
      },
      "http_status": {
       "type": "integer"
      },
      "payment_required": {
       "type": "object"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "verdict": "PAYABLE",
  "latency_s": 0.95,
  "http_status": 402,
  "payment_required": {
   "valid": true,
   "options": [
    {
     "network": "eip155:8453",
     "price_usd": "0.003",
     "asset_symbol": "USDC"
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-tools-preflight-checker-569a45cb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-tools-7936.onrender.com](https://www.zero.xyz/host/agent-tools-7936.onrender.com/llms.txt)