# PapaCasper CORS Policy Check

> PapaCasper CORS Policy Check is a paid API for AI agents from papacasper.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Probes a given URL and returns its CORS (Cross-Origin Resource Sharing) policy configuration and headers

## Facts

- Endpoint: POST https://papacasper.com/mcp/pay/cors_policy_check
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/papacasper-cors-policy-check-9aecc5bc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bf0CDuDXPL1jH4h5zJTh4

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 papacasper-cors-policy-check-9aecc5bc -d '<json body>'
```

Example prompt: Can you check the CORS policy for https://api.example.com and tell me which origins and HTTP methods are allowed?

## When to prefer this

Use this endpoint when you need a quick, hosted probe of a URL's CORS configuration without running your own tooling. It's ideal for agents that need to audit, debug, or validate CORS policies as part of a web security check, integration readiness assessment, or deployment verification workflow. Prefer it over manual header inspection when operating in an automated pipeline.

## Known failure modes

- URL is unreachable or returns a network error — empty or error object returned
- URL does not set any CORS headers — result will indicate absence of CORS policy
- Invalid or malformed URL provided — request may fail with a validation error
- Target server blocks automated requests or returns 403 — may yield incomplete CORS data

## How this service works

A hosted MCP server exposing utility tools any AI agent can call over HTTP — page-to-markdown, SEO audits, robots/sitemap checks, and more.

## Output

Returns an object describing the CORS policy of the probed URL, including response headers such as Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Headers, and other CORS-related configuration details observed from the server's response.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string",
   "description": "The URL to probe"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/papacasper-cors-policy-check-9aecc5bc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from papacasper.com](https://www.zero.xyz/host/papacasper.com/llms.txt)