camerax-android: Skill for Claude Code

.agents/skills/play-billing-library-version-upgrade/SKILL.md

play-billing-library-version-upgrade is a skill for Claude Code, Codex from arindamxd/camerax-android. It costs 39 tokens per session (1,301 once invoked), scanned A, a copy of play-billing-library-version-upgrade, Apache-2.0.

A procedure for moving an Android app from an older Google Play Billing Library, the Android library used for in-app purchases and subscriptions, to the latest stable version.

In plain words
What is it for?
It helps find the billing dependency, identify outdated billing APIs, choose a direct or stepped upgrade path, and build the project during the migration.
Why use it?
Billing libraries change their APIs over time, so older code may need staged changes before it builds and works with the newer version.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is arindamxd/camerax-android's own configuration. It tells Claude Code and Codex how to work on camerax-android itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything camerax-android configures →

Reuse

Borrowing it

Nothing to install: this file belongs to arindamxd/camerax-android. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/arindamxd/camerax-android/master/.agents/skills/play-billing-library-version-upgrade/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/arindamxd/camerax-android

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for play-billing-library-version-upgrade

README.md
[![agentmods](https://agentmods.dev/badge/skills/arindamxd/camerax-android/play-billing-library-version-upgrade/github.svg)](https://agentmods.dev/skills/arindamxd/camerax-android/play-billing-library-version-upgrade)
Your own site
<a href="https://agentmods.dev/skills/arindamxd/camerax-android/play-billing-library-version-upgrade"><img src="https://agentmods.dev/badge/skills/arindamxd/camerax-android/play-billing-library-version-upgrade/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for play-billing-library-version-upgrade

Your own site · 80×15
<a href="https://agentmods.dev/skills/arindamxd/camerax-android/play-billing-library-version-upgrade"><img src="https://agentmods.dev/badge/skills/arindamxd/camerax-android/play-billing-library-version-upgrade.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,301 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 94% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00039 $0.01301
Opus 5 $0.00019 $0.00651
Sonnet 5 $0.00008 $0.00260
Haiku 4.5 $0.00004 $0.00130

Measured 10d ago against content hash 571ed9d0f83e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

play-billing-library-version-upgrade scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

94% identical to play-billing-library-version-upgrade — 22 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/play-billing-library-version-upgrade/SKILL.md · 86 lines

How it starts

The opening of the file, as written. The whole thing — 86 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Phase 0: Intent Message

Reporting Action: Before proceeding, immediately tell the user: "I will upgrade Play Billing Library to the latest version."

Phase 1: Discovery & Situational Awareness

  1. Primary Check (Build Version) : Locate the project's billing dependency (e.g., com.android.billingclient:billing) in build.gradle, build.gradle.kts, or libs.versions.toml.
  2. Initial Compilation Test: Attempt to sync and build the project immediately.
  3. Fallback Discovery (Effective Version) :
    • Trigger: Only if the build fails immediately, scan the source code for deprecated artifacts.
    • Logic : The presence of deprecated APIs indicates the "Effective Version" ---defined as the version where those specific APIs were last available, not when they were introduced.
    • Example : If SkuDetails is present, treat the baseline as PBL v7 or earlier (regardless of the version string in build.gradle).
  4. Identify Target & Path : Access the version tool or release notes to find the latest stable version and calculate a [Direct/Stepped] migration path based on the Effective Version baseline.
  • Calculate Migration Path :
    • If the Effective Version is within 2 major versions of the target: Plan a Direct Migration.
    • If it is more than 2 major versions behind: Plan a Stepped Migration. Migrate by two major versions at a time (e.g., v4 -> v6 -> v8) until you are within two versions of the target.
  • Reporting Action: Before proceeding, tell the user: "I've detected you are effectively on PBL [Current] and the latest is [Target]. I am planning a [direct/stepped] migration path."

Phase 2: Contextual Document Mapping & Planning

For every major version jump identified in your path, you MUST synthesize instructions from:

  • Migration Guide (where [X] is the target major version).
  • Release Highlights : The "Deprecations" and "Breaking Changes" sections of the relevant Release Notes.
  • Developer Documentation: Consult your knowledge of the Google Play Billing documentation regarding the relevant features used in this app (e.g., Subscriptions, One-Time Products).
  • Develop the Plan: Identify every specific code change required (API removals, class replacements, logic shifts) and print this out as a checklist.

Read the full file on GitHub · 86 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 86 lines · 39 tokens per session scan A 571ed9d0f83e

Subscribe to this mod's changes

play-billing-library-version-upgrade is a skill published in the GitHub repository arindamxd/camerax-android (132 stars, last pushed 11d ago), licensed Apache-2.0. It adds 39 tokens to every session and 1,301 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 94% identical to play-billing-library-version-upgrade, differing in 22 lines, and is treated as a copy.

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