# Services from x402-catalog-history.ai-business-surface.workers.dev on Zero

> x402-catalog-history.ai-business-surface.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/x402-catalog-history.ai-business-surface.workers.dev
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/x402-catalog-history.ai-business-surface.workers.dev/health.json

## Services

- [IPv4 CIDR Calculator](https://www.zero.xyz/c/ipv4-cidr-calculator-0419c470/llms.txt): $0.001/call via x402. Computes full IPv4 subnet details (network, broadcast, netmask, host range, counts, and scope flags) from a CIDR notation input in a single GET request.
- [Public Holidays by Country and Year](https://www.zero.xyz/c/public-holidays-by-country-and-year-4f82701c/llms.txt): $0.003/call via x402. Returns all public holidays for a given country and year, including dates, local and English names, types, weekday, and days-from-today offsets, sourced live from Nager.Date.
- [URL Inspector — Parse Scheme, Host, Query Params & Normalized Form](https://www.zero.xyz/c/url-inspector-parse-scheme-host-query-params-normalized-form-0d185070/llms.txt): $0.001/call via x402. Parses a single absolute HTTP(S) URL into its components: scheme, host, port, origin, path, path segments, query parameters (with duplicates), fragment, and normalized href — without fetching or storing anything.
- [x402-crosschain-gas](https://www.zero.xyz/c/x402-crosschain-gas-2856a74e/llms.txt): $0.001/call via x402. Returns real-time gas prices (in gwei and wei) for up to five EVM chains — Base, Ethereum, Arbitrum, Optimism, and Polygon — including base fee, priority fee, next block base fee, and block metadata, sourced directly from public RPCs.
- [Random Item Picker (Uniform, No-Replacement)](https://www.zero.xyz/c/random-item-picker-uniform-no-replacement-80721645/llms.txt): $0.001/call via x402. Picks a specified count of random items from a user-supplied list using cryptographically secure randomness, returning the chosen items and their 0-based indices
- [x402 Contract Inspector](https://www.zero.xyz/c/x402-contract-inspector-e90809ea/llms.txt): $0.02/call via x402. Fetches and normalizes the output contract declared by any x402 paywalled URL, listing field names, types, required flags, and examples before you pay.
- [x402-seller-playbook](https://www.zero.xyz/c/x402-seller-playbook-b015af46/llms.txt): $3/call via x402. Delivers a comprehensive guide for building and operating x402-protocol payment-gated endpoints, including 402 challenge format, facilitator verification rules, delivery evidence, and USDC receiving setup on Base.

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)