# HEAD /s/:slug – Check Hosted Site Existence and Metadata

> HEAD /s/:slug – Check Hosted Site Existence and Metadata is a paid API for AI agents from site.withzero.ai, paid per call via MPP, price unknown, status unknown (last checked 2026-09-29).

Returns HTTP headers for a hosted site slug without downloading its body, allowing existence checks, cache validation, and metadata retrieval.

## Facts

- Endpoint: HEAD https://site.withzero.ai/s/:slug?utm_source=zero.xyz
- Price: price unknown
- Payment: MPP
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Provider: site.withzero.ai
- Website: https://site.withzero.ai
- Canonical page: https://www.zero.xyz/c/site-withzero-ai-head-s-slug-check-hosted-site-existence-and-metadata-b4bfd67c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_h2yJvbxjMSLNOKqgZgndu

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 site-withzero-ai-head-s-slug-check-hosted-site-existence-and-metadata-b4bfd67c -d '<json body>'
```

Example prompt: Can you check if the hosted page at slug 'my-launch-page' on withzero.ai is still live and accessible, without actually downloading the content?

## When to prefer this

Use this endpoint when you need to check the existence, freshness, or metadata of a hosted page without the overhead of downloading its full HTML body — ideal for polling, existence checks, cache validation, or pre-flight verification before a GET request.

## Known failure modes

- 404 Not Found if the slug does not exist or has been deleted
- 410 Gone if the site was deleted early
- 503 if the hosting service is temporarily unavailable
- Unexpected 301/302 redirect if a custom domain alias is in effect

## How this service works

HEAD variant of /s/:slug.

## Output

HTTP response headers including status code (200 if exists, 404 if not found), content-type, cache-control, ETag, and last-modified — with no response body transferred.

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/site-withzero-ai-head-s-slug-check-hosted-site-existence-and-metadata-b4bfd67c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from site.withzero.ai](https://www.zero.xyz/host/site.withzero.ai/llms.txt)