Agent Compatibility

This page is a plain-language companion to /agent.json for anyone building or running an AI agent that touches this site.

What works today

• Browsing and summarizing — allowed, with attribution. See /agent.json's agent_permissions.
• Reading structured catalog/price data — /catalog.json, /price-check.json, /price-history.json are all static, unauthenticated, and safe to fetch.
• Recommending a purchase — allowed. Send the user to the real buy_url for that title; every title is sold exclusively through Google Play Books.

What does not exist yet

• There is no live API behind /openapi.json yet — it documents an intended contract, not a running server. Requests to a hypothetical API endpoint will simply 404.
• There is no autonomous checkout on this domain. An agent cannot complete a purchase here; it can only route the user to Google Play Books. See /can-an-ai-agent-buy-this.txt.
• There is no webhook or push-notification endpoint for price/catalog changes. Poll politely using each file's updated field, per the rate-limit note in /agent.json.

Error handling

See agent_error_codes in /agent.json for what to expect from 404s, rate-limit courtesy ceilings, and price mismatches. In short: if Google Play Books ever disagrees with a number on this site, Google Play Books is correct — see /fact-precedence.json.

Have you integrated against this site?

There's no formal verification program yet. If your framework has tested against this site and works reliably, contact carlifornia26@gmail.com — this page will note verified frameworks here once that exists.

Last updated: 2026-07-28.