# Services from cited-brief.cited-brief.workers.dev on Zero

> cited-brief.cited-brief.workers.dev serves 7 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/cited-brief.cited-brief.workers.dev
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/cited-brief.cited-brief.workers.dev/health.json

## Services

- [Cited Brief – Check Quote](https://www.zero.xyz/c/cited-brief-check-quote-2ef7f53f/llms.txt): $0.01/call via x402. Verifies whether specific exact-text quotes appear on a given public web page, returning found/not-found status with surrounding context
- [Cited Brief](https://www.zero.xyz/c/cited-brief-39455905/llms.txt): $0.1/call via x402. Answers a user question by extracting and citing evidence from specified web pages, returning a verified answer with source quotes
- [Cited Brief Page Text Extractor](https://www.zero.xyz/c/cited-brief-page-text-extractor-97fb31a8/llms.txt): $0.01/call via x402. Fetches and returns the plain text content of a public web page, up to a configurable character limit, paid per call in USDC via x402.
- [Cited Brief DOI Checker](https://www.zero.xyz/c/cited-brief-doi-checker-3fa83b80/llms.txt): $0.01/call via x402. Validates DOIs, arXiv IDs, and doi.org links against Crossref to confirm existence, check for retractions, and verify cited titles match the real publication metadata.
- [Cited Brief – Check Links](https://www.zero.xyz/c/cited-brief-check-links-6d7acaf9/llms.txt): $0.01/call via x402. Checks up to 10 public URLs for reachability, HTTP status, redirects, and content metadata
- [Cited Brief Robots.txt Check](https://www.zero.xyz/c/cited-brief-robots-txt-check-a3ef7b97/llms.txt): $0.01/call via x402. Checks whether a given URL is allowed or disallowed by the target site's robots.txt for a specified crawler user agent
- [Cited Brief Domain Check](https://www.zero.xyz/c/cited-brief-domain-check-650793e6/llms.txt): $0.02/call via x402. Performs a comprehensive WHOIS/RDAP and DNS lookup for a given domain, returning registration status, DNS records, expiry, and email infrastructure details.

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)