# Services from kairostamp.com on Zero

> kairostamp.com serves 10 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero.

Canonical page: https://www.zero.xyz/host/kairostamp.com
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/kairostamp.com/health.json

## Services

- [Kairostamp Change Check](https://www.zero.xyz/c/kairostamp-change-check-c51a526d/llms.txt): $0.05/call via x402. Fetches a public URL server-side, compares its response body against a prior SHA-256 or Kairostamp receipt, and returns whether the content changed along with a new tamper-evident timestamped evidence receipt.
- [Kairostamp URL Digest Receipt](https://www.zero.xyz/c/kairostamp-url-digest-receipt-afc6e8ea/llms.txt): $0.01/call via x402. Fetches a public URL server-side and returns a tamper-evident receipt containing HTTP status, final URL, content type, byte length, SHA-256 hash, redirect chain, and a hash-chain entry for audit integrity.
- [Kairostamp Evidence Snapshot](https://www.zero.xyz/c/kairostamp-evidence-snapshot-0805f05a/llms.txt): $0.05/call via x402. Fetches a public URL server-side and returns a tamper-evident, time-stamped receipt with status, content type, byte length, SHA-256 hash, redirect chain, text preview, and hash-chain entry for evidentiary purposes.
- [Kairostamp Robots.txt Checker](https://www.zero.xyz/c/kairostamp-robots-txt-checker-0dbb99c3/llms.txt): $0.005/call via x402. Server-side fetches a site's robots.txt and evaluates whether a given URL path is allowed or blocked for a specified user agent, returning the decision, matched rule, HTTP status, and a tamper-evident timestamped receipt.
- [Kairostamp Link Map](https://www.zero.xyz/c/kairostamp-link-map-b0474fbe/llms.txt): $0.015/call via x402. Fetches a single public HTML page server-side and returns up to 100 normalized, deduplicated HTTP/HTTPS links with internal/external classification, counts, final URL, timestamp, and a tamper-evident receipt.
- [Kairostamp Text Extract](https://www.zero.xyz/c/kairostamp-text-extract-dcb45db3/llms.txt): $0.02/call via x402. Fetches a public HTML page server-side and returns clean plain text with provenance metadata including a tamper-evident receipt
- [Kairostamp HTTP Metadata Receipt](https://www.zero.xyz/c/kairostamp-http-metadata-receipt-424db91a/llms.txt): $0.005/call via x402. 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.
- [Kairostamp Redirect Audit](https://www.zero.xyz/c/kairostamp-redirect-audit-53be23fa/llms.txt): $0.01/call via x402. Follows a public URL server-side and returns the full redirect chain with hop count, final URL, final status, cross-origin and HTTPS-downgrade flags, plus a tamper-evident receipt.
- [Kairostamp Sitemap Lookup](https://www.zero.xyz/c/kairostamp-sitemap-lookup-68914953/llms.txt): $0.01/call via x402. Locates and fetches a site's sitemap (from robots.txt or /sitemap.xml), returning up to 100 normalized URLs with metadata and a tamper-evident receipt.
- [Kairostamp Receipt Verification](https://www.zero.xyz/c/kairostamp-receipt-verification-11ab6e11/llms.txt): $0.005/call via x402. Verifies an existing Kairostamp receipt by recomputing its SHA-256 digest, checking hash-chain linkage to the preceding entry, and reporting whether it is covered by an on-chain checkpoint.

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

- [Zero catalog index](https://www.zero.xyz/llms.txt)