# Strale API — Paid API Preflight Check

> Strale API — 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 2026-09-14).

Checks whether a paid API endpoint is reachable and ready to accept x402 micropayments before committing funds

## Facts

- Endpoint: GET https://api.strale.io/x402/v2/paid-api-preflight
- Price: $0.0216/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/strale-api-paid-api-preflight-check-74430b3a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5d9e8izDNu4flkxh4ex4G

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 strale-api-paid-api-preflight-check-74430b3a
```

Example prompt: Before we pay for that Strale data endpoint, can you run a preflight check on https://api.strale.io/x402/v2/some-endpoint using a GET request to make sure it's up and accepting payments?

## When to prefer this

Use this endpoint as a guard step before making any paid x402 API call, especially in automated agent workflows where a failed payment attempt would waste USDC. Prefer this over directly calling the target endpoint when you need to confirm payment infrastructure is working, when building retry logic, or when orchestrating multi-step pipelines that depend on a paid API being available.

## Known failure modes

- Target endpoint URL is unreachable or returns non-402 status — preflight reports endpoint not payment-ready
- Invalid or malformed URL in queryParams — schema validation error returned
- HTTP method not in allowed enum (GET, HEAD, DELETE) — request rejected
- Endpoint temporarily down — preflight returns unavailable status

## How this service works

The trust layer for AI agents — 250+ independently tested data capabilities across 27 countries. Execute capabilities via REST, MCP, A2A, or x402 micropayments. Every call returns an audit record with cryptographic chain hashing.

## Output

Returns a status indicating whether the specified paid API endpoint URL is reachable and ready to process x402 micropayment requests, allowing agents to confirm endpoint availability before committing funds. No payment is charged for the preflight call itself.

## 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/strale-api-paid-api-preflight-check-74430b3a/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)