The web's fastest-growing user base isn't human — it's AI agents. Just as UX taught us to design for users and DX for developers, AX (Agent Experience) is the discipline of designing for agents.
This guide walks through six stages — Discovery, Identity, Auth & Access, Integration, Errors & Recovery, End-User Experience — with concrete code examples and patterns. Includes the AX Maturity Model (Level 0–5), 25+ anti-patterns catalogued from real-world services, and a practical readiness checklist.
Bilingual EN/ZH, built on Astro v6 with Playwright e2e tests. Designed to be agent-readable itself: ships with llms.txt, AGENTS.md, auth.md, and capabilities.json.