# Kairostamp HTTP Metadata Receipt

> Kairostamp HTTP Metadata Receipt is a paid API for AI agents from kairostamp.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-16).

Fetches a public URL server-side and returns only HTTP transport metadata (status code, final URL, redirect chain, content type, byte length) plus a receipt ID — no response body is returned or stored.

## Facts

- Endpoint: GET https://kairostamp.com/api/v1/headers
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/kairostamp-http-metadata-receipt-424db91a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_82d0_AVY5kohrxSIkfQKu

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 kairostamp-http-metadata-receipt-424db91a
```

Example prompt: Can you probe https://example.com/report.pdf server-side and tell me the HTTP status, content type, byte size, and whether it redirected anywhere — without actually downloading the file?

## When to prefer this

Choose this endpoint when you need lightweight HTTP transport metadata for a URL — status, content type, size, or redirect chain — without needing the actual response body. It is ideal for pre-flight checks, link validation, redirect auditing, and size estimation. Prefer it over a full fetch/scrape endpoint when you only care about headers and transport-level facts, and when having a timestamped receipt ID for auditability is useful.

## Known failure modes

- Non-public or firewalled URLs may return connection errors or timeouts
- Malformed or non-HTTP/HTTPS URLs will be rejected by schema validation
- URLs that return very large responses may hit byte-read limits
- The target server may block server-side user agents, resulting in 403 or 429 status codes
- DNS resolution failures for unknown hosts will produce an error response

## How this service works

URL HTTP metadata receipt: server-side fetch of one public http/https URL, returning only transport metadata — HTTP status, final URL, redirect chain, content type and byte length — plus a receipt id. The response body is not returned and no content preview is stored. Single GET query parameter (url).

## Output

A JSON object containing a unique receipt_id (UUID), and an 'http' object with: the final URL after redirects, a fetched_at ISO-8601 timestamp, HTTP status code (integer), content_type (string or null), byte_length (integer), and redirect_chain (ordered array of intermediate URLs). The response body of the fetched URL is never returned.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/kairostamp-http-metadata-receipt-424db91a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kairostamp.com](https://www.zero.xyz/host/kairostamp.com/llms.txt)