What is play-billing-skills?

Play Billing Skills is a collection of 45 instruction recipes for AI coding agents that help developers integrate in-app purchases and subscriptions into Android apps. The recipes are published by RevenueCat, a company that provides subscription infrastructure for mobile apps, and they draw from two official RevenueCat guides covering Google Play Billing and the RevenueCat Android SDK. Android in-app billing is genuinely complex. Google's Play Billing Library handles the purchase transaction, but the surrounding lifecycle involves many edge cases that separate a working demo from a production-quality integration: grace periods, account holds, price changes, refunds, subscription pauses, plan switches, fraud prevention, and server-side receipt verification. These skills encode the specific patterns, API response codes, and common pitfalls that matter in production. The 45 skills are split into two collections. One targets developers who integrate Google's Play Billing Library directly and run their own backend for receipt verification. The other targets developers who use RevenueCat's SDK to abstract away most of that complexity. A comparison skill explains the trade-offs between the two approaches side by side. Each skill is a markdown file with YAML frontmatter that AI coding agents use to recognize when a recipe applies. When a developer asks their agent to set up RTDN or handle a failed renewal, the agent matches the request to the correct skill and follows the numbered workflow inside it, including handoffs to prerequisite skills if earlier steps are incomplete. Installation involves cloning the repository and running a bundled shell script that creates symlinks in the agent's expected skill directory. Instructions cover Claude Code, Android Studio Agent mode, Gemini CLI, Cursor, and manual use in any agent that can read markdown files.