# Services from preflight402.com on Zero

> preflight402.com serves 8 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/preflight402.com
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/preflight402.com/health.json

## Services

- [Preflight402 Dependency Existence Checker](https://www.zero.xyz/c/preflight402-dependency-existence-checker-14d7ab53/llms.txt): $0.05/call via x402. Checks whether npm, PyPI, or crates package names actually exist in their registries and returns closest real alternatives for hallucinated (non-existent) package names.
- [Preflight EU Legal Citation Checker](https://www.zero.xyz/c/preflight-eu-legal-citation-checker-e60dc16b/llms.txt): $0.1/call via x402. Verifies that a cited EU law instrument, article, and quoted text are accurate before publishing a claim, returning the official article text and a EUR-Lex link.
- [Preflight EU AI Act Obligations Lookup](https://www.zero.xyz/c/preflight-eu-ai-act-obligations-lookup-6b491c1d/llms.txt): $0.1/call via x402. Returns EU AI Act articles (with headings, excerpts, and EUR-Lex links) that mention a specific obligation topic for a given actor role and risk tier.
- [Preflight Bitcoin Transaction Inspector](https://www.zero.xyz/c/preflight-bitcoin-transaction-inspector-6e5c84f2/llms.txt): $0.1/call via x402. Decodes a raw Bitcoin transaction hex or PSBT and returns inputs, outputs, script types, addresses, vsize, fee rate, RBF flags, dust outputs, non-standard sighash flags, and unsigned inputs — offline, no network access.
- [Preflight EVM Transaction Inspector](https://www.zero.xyz/c/preflight-evm-transaction-inspector-0d948800/llms.txt): $0.1/call via x402. Decodes raw Ethereum or Base transaction bytes or calldata against standard interfaces (ERC-20, ERC-721, ERC-1155, WETH, EIP-2612 Permit, Permit2) and returns the decoded method signature, typed parameters, value in wei, and spec links.
- [Preflight CVE Validator](https://www.zero.xyz/c/preflight-cve-validator-6503adae/llms.txt): $0.05/call via x402. Checks whether CVE identifiers are real, published, or rejected — catching hallucinated vulnerability references before an agent acts on them.
- [Preflight Package Version Check](https://www.zero.xyz/c/preflight-package-version-check-83435ee9/llms.txt): $0.05/call via x402. Verifies that a specific package version exists in npm, PyPI, or crates.io, returning its publication timestamp, deprecation/yanked status, artifact hashes, and optional SRI/hex digest comparison.
- [Preflight Bitcoin Transaction Input Context](https://www.zero.xyz/c/preflight-bitcoin-transaction-input-context-16d34a7a/llms.txt): $0.1/call via x402. Looks up chain context for Bitcoin transaction inputs — checking if each prevout exists, is spent, its value in satoshis, and its confirmation count — before signing.

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)