# Paid API Preflight Check

> Paid API Preflight Check is a paid API for AI agents from api.strale.io, paid per call via x402, $0.0216/call, status unknown (last checked 2026-09-15).

Verifies a paid API endpoint's reachability, SSL, response time, and payment protocol handshake before an agent spends money on it

## Facts

- Endpoint: GET https://api.strale.io/x402/paid-api-preflight
- Price: $0.0216/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-strale-io-7775f06f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FT3i8SJQlI2nuaUPIE42i

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 api-strale-io-7775f06f
```

Example prompt: Before we call that paid weather API at https://api.example.com/weather, can you run a preflight check on it to make sure it's reachable, SSL is valid, and the payment handshake is legitimate — I want a proceed/caution/avoid recommendation before we spend anything.

## When to prefer this

Use this endpoint whenever an AI agent is about to call an unknown or untrusted paid API and needs to verify it is legitimate, reachable, and correctly implements a payment protocol (x402, L402, MPP) before committing funds. Especially valuable in agentic workflows where automated spending decisions are made without human review of each individual call.

## Known failure modes

- Target URL is unreachable or returns unexpected errors
- SSL certificate invalid or expired on target endpoint
- Payment protocol handshake not recognized or malformed
- Missing required 'url' query parameter returns validation error
- Target API does not implement a recognized payment protocol

## How this service works

Verify any paid API endpoint before your agent spends money. Checks reachability, SSL, response time, and validates the payment protocol handshake (L402, x402, MPP). Returns a proceed/caution/avoid recommendation with parsed payment details. Use this befo…

## Output

Returns a structured report including a proceed/caution/avoid recommendation, reachability status, SSL validity, response time, detected payment protocol (L402/x402/MPP), parsed payment details (asset, price, payTo address, network), and a list of any issues found.

## Example request

```json
{
 "url": "https://api.example.com/weather"
}
```

## 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 paid API endpoint URL to check before paying"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-strale-io-7775f06f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.strale.io](https://www.zero.xyz/host/api.strale.io/llms.txt)