# AgentShelf URL HTTP Scheme Checker

> AgentShelf URL HTTP Scheme Checker is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-11).

Checks whether a given URL uses the HTTP (not HTTPS or other) scheme, returning a boolean result without fetching the URL.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-url-http?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-url-http-scheme-checker-f738ccf3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Q6dift70dzg7hC5A4ky6I

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 agentshelf-url-http-scheme-checker-f738ccf3 -d '<json body>'
```

Example prompt: Can you check whether the URL http://example.com/page is using the HTTP scheme — not HTTPS or anything else, just a straight scheme check without fetching the page?

## When to prefer this

Use this endpoint when you need a lightweight, no-fetch check to determine whether a URL string uses the HTTP scheme. It is appropriate when you only care about the scheme portion of the URL and do not need to retrieve or parse page content. Prefer the free sandbox alternative (/v1/sandbox/check-url-http) if available before incurring the $0.005 USDC cost.

## Known failure modes

- Empty or missing URL value returns an error
- Malformed input that is not a valid URL string may return an error or unexpected result
- Ambiguous scheme (e.g. protocol-relative URLs starting with //) may not match as http
- Service unavailability returns a non-200 response or payment-related 402 error

## How this service works

Call when an agent needs whether a URL uses the http scheme. No fetch. Send JSON {"value":"http://example.com/a"}. Exact $0.005 USDC on Base. Try unpaid POST /v1/sandbox/check-url-http first.

## Output

Returns a validation result indicating whether the provided URL uses the 'http' scheme (as opposed to 'https', 'ftp', or other schemes). No network fetch is performed — the check is purely scheme-based on the string value of the URL.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "description": "JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN."
  },
  "value": {
   "type": "string",
   "examples": [
    "http://example.com/a"
   ],
   "maxLength": 20000,
   "minLength": 1,
   "description": "Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar."
  },
  "schema": {
   "description": "JSON Schema document for schema-check SKUs. Omit it on string checks."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentshelf-url-http-scheme-checker-f738ccf3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)