# x402check blog

- [How to check an x402 endpoint before your agent pays](https://x402check.dev/blog/how-to-check-x402-before-paying) (2026-11-02) · A practical preflight flow for AI agents that pay x402 APIs with USDC on Base: live 402, payTo, price, and what to do with ok, caution, and avoid.
- [5 x402 listing mistakes that cost agents money](https://x402check.dev/blog/five-x402-listing-mistakes) (2026-11-02) · Anonymized patterns from real Bazaar and 402 Index listings that disagree with live 402 quotes: stale prices, old wallets, retired routes, and dynamic pricing.
- [Using x402check in CI with the GitHub Action](https://x402check.dev/blog/x402check-github-action-ci) (2026-11-02) · Fail or warn your builds when an x402 seller's price, payTo, or network drifts. Setup for the x402check Endpoint Preflight Action.
- [One line that checks every x402 payment before it goes through](https://x402check.dev/blog/auto-preflight-with-wrapfetch) (2026-11-02) · How wrapFetch on x402check-client adds a check before paying so agents and apps do not settle blind.