rc-backend

Q: How do I install rc-backend?

Run npx skills add https://github.com/revenuecat/ai-toolkit --skill rc-backend in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/rc-backend/ (personal) or .claude/skills/rc-backend/ (project).

by revenuecatBackend & APIs

Use this skill when your backend needs to read or update RevenueCat state on Android. Covers the RevenueCat REST API (v1 subscribers endpoint, grant/revoke entitlements, attributes), secret vs public SDK API key usage, and why you do not build a receipt verification backend with RevenueCat.

Installs: 644
Last 24h: —
Trending rank: —
Security: Not audited

Install

Works with every agent the skills CLI supports.

npx skills add https://github.com/revenuecat/ai-toolkit --skill rc-backend

01
Install
Run the command in your project. The CLI asks which agents to install for.
02
Describe the task
Ask your agent for something this skill covers. It loads rc-backend automatically when relevant.
03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.

SKILL.md

The instructions your agent reads when the skill is triggered.

Backend Architecture with RevenueCat

You do not build a receipt verification server with RevenueCat. Your backend still has a role, but that role is consuming RevenueCat state, not validating Google Play purchase tokens.

Phase 1: Discovery

RevenueCat's backend is the receipt verification server. When the Android SDK posts a purchase token, RevenueCat's backend:

Calls purchases.subscriptionsv2.get or purchases.products.get against the Google Play Developer API.
Validates the receipt is genuine and matches the expected product.
Records the transaction in its database.
Returns CustomerInfo to the SDK.

Your Android app never calls the Google Play Developer API. Your server does not call it either.

Before writing any backend code, confirm these facts about your deployment:

You have a RevenueCat project with an Android app configured.
You have a secret API key from Project Settings to API Keys (not the public Android SDK key embedded in the app).
You know which app_user_id your SDK uses (the same identifier your auth system uses).
You have decided whether the backend needs real time state (REST API) or event driven state (webhooks).

If your app only gates features inside the client, you may not need a backend component at all. RevenueCat verifies CustomerInfo server side before it reaches the SDK, and EntitlementVerificationMode.INFORMATIONAL or .ENFORCED adds signature verification on the client. Serve premium content from a server only when you can verify entitlement on the server.

Phase 2: Plan

Map each backend responsibility to a RevenueCat mechanism.

Use case	Mechanism	Notes
React to purchase, renewal, cancellation	Webhook receiver	RevenueCat posts normalized events; your server updates its own DB.
Check current entitlement for a user	`GET /v1/subscribers/{app_user_id}`	Secret API key in `Authorization` header.
Grant promotional access (support, refunds, comps)	`POST /v1/subscribers/{app_user_id}/entitlements/{entitlement_id}/promotional`	Server side only.
Revoke promotional access	`POST /v1/subscribers/{app_user_id}/entitlements/{entitlement_id}/revoke_promotionals`	Server side only.
Set subscriber attributes from server side data	`POST /v1/subscribers/{app_user_id}/attributes`	Useful for CRM fields the SDK does not know.
Bulk data export	RevenueCat data export	Scheduled exports to your warehouse.

What your backend still owns:

User authentication.
Your database of users and their access levels.
API endpoints that serve premium content.
The webhook receiver that processes RevenueCat events.

What your backend does not own:

Google Play Developer API credentials.
Receipt verification code.
linkedPurchaseToken chain traversal.
Subscription state computation across the seven subscription states.

Phase 3: Execute

Read a subscriber

GET https://api.revenuecat.com/v1/subscribers/{app_user_id}
Authorization: Bearer sk_...
X-Platform: android

The response body is the same CustomerInfo structure the Android SDK returns. Use it in a server side endpoint that gates premium API responses.

Grant a promotional entitlement

POST https://api.revenuecat.com/v1/subscribers/{app_user_id}/entitlements/{entitlement_id}/promotional
Authorization: Bearer sk_...
Content-Type: application/json

{"duration": "monthly"}

Valid duration values include daily, three_day, weekly, monthly, two_month, three_month, six_month, yearly, lifetime. Use this for support workflows, never from the client.

Example: Kotlin Ktor call from your server

val response = client.get("https://api.revenuecat.com/v1/subscribers/$appUserId") {
    header("Authorization", "Bearer ${System.getenv("RC_SECRET_KEY")}")
    header("X-Platform", "android")
}

API key rules

Key	Where it lives	What it can do
Android public SDK key	Embedded in the Android app	Post purchases, fetch `CustomerInfo` for the current user.
Secret API key	Server environment variable only	Read any subscriber, grant or revoke promotionals, set attributes, bulk operations.

Never ship the secret key in the Android APK, in a BuildConfig field, or in any client bundle. Rotate it if it leaks. Treat it like a database password.

Webhook receiver outline

post("/revenuecat/webhook") {
    val auth = call.request.header("Authorization")
    require(auth == "Bearer ${System.getenv("RC_WEBHOOK_SECRET")}")
    val event = call.receive<RevenueCatEvent>()
    when (event.type) {
        "INITIAL_PURCHASE", "RENEWAL" -> grantAccess(event.appUserId, event.entitlements)
        "CANCELLATION", "EXPIRATION" -> scheduleRevocation(event.appUserId)
    }
    call.respond(HttpStatusCode.OK)
}

Verify the authorization header you configured in the RevenueCat dashboard. Respond 2xx fast; RevenueCat retries on non 2xx responses.

What not to build

Do not build a Google Play receipt verification endpoint. RevenueCat already did.
Do not pass purchase tokens from the Android client to your server for manual verification. The SDK handles the round trip.
Do not query Google Play Developer API from your backend unless you are building a custom integration that bypasses the SDK.
Do not mirror the seven subscription state machine in your DB. Consume CustomerInfo.entitlements.active or webhook events instead.

References

Full chapter

FAQ

What does the rc-backend skill do?

How do I install rc-backend?

Run npx skills add https://github.com/revenuecat/ai-toolkit --skill rc-backend in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/rc-backend/ (personal) or .claude/skills/rc-backend/ (project).

Which AI agents can use rc-backend?

Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.

Is rc-backend safe to install?

No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.

Who maintains rc-backend?

It is published by revenuecat in revenuecat/ai-toolkit. It has 644 recorded installs.

More from revenuecat/ai-toolkit

View all →

revenuecat-paywall

revenuecat/ai-toolkit

Display a RevenueCat paywall inside an app using the RevenueCatUI SDK. Use when the user asks to add a paywall, show a RevenueCat paywall, present PaywallView, integrate RevenueCatUI, gate a premium screen with a paywall, launch PaywallActivity, call presentPaywall or presentPaywallIfNeeded, or show the dashboard configured paywall UI on iOS, Android, Kotlin Multiplatform, Flutter, or React Native. To create, edit, evaluate, or audit the dashboard paywall itself, use revenuecat-paywall-design.

Mobile1.1K installs

integrate-revenuecat

revenuecat/ai-toolkit

End-to-end RevenueCat integration — sets up the dashboard side via the RevenueCat MCP or the rc CLI (project, app, public API key) and installs/configures the Purchases SDK in the app. Use when the user asks to add RevenueCat, hook up RevenueCat, add subscriptions or in-app purchases to an app, integrate Purchases, install the RevenueCat SDK, set up a RevenueCat API key, configure Purchases on launch, or set up a brand new RevenueCat integration on iOS, Android, Kotlin Multiplatform, Flutter, or React Native.

Mobile1.1K installs

revenuecat-purchase-flow

revenuecat/ai-toolkit

Implement the RevenueCat purchase and restore flow. Use when the user asks to buy a package, purchase a subscription, fetch offerings, build the purchase logic behind a custom (hand-coded) paywall, handle purchase errors, detect user cancelled, or restore previous purchases on iOS, Android, Kotlin Multiplatform, Flutter, or React Native.

Mobile987 installs

revenuecat-testing-setup

revenuecat/ai-toolkit

Set up a testing environment for RevenueCat purchases without charging real money. Use when the user says test RevenueCat purchases, sandbox setup, StoreKit configuration file, license tester, how do I test purchases without real money, set up sandbox account, internal testing track, or test paywall on iOS, Android, Kotlin Multiplatform, Flutter, or React Native.

Testing & QA901 installs

create-revenuecat-project

revenuecat/ai-toolkit

Set up a complete RevenueCat project from scratch — creates apps, products, entitlements, offerings, and packages in the correct order. Use when the user wants to create a new RevenueCat project, configure in-app purchases, set up subscriptions or monetization, or bootstrap IAP infrastructure for iOS, Android, or Web.

Mobile882 installs

revenuecat-troubleshoot

revenuecat/ai-toolkit

Diagnose and resolve RevenueCat integration issues — inspects dashboard configuration through the RevenueCat MCP, walks the SDK debug logs, and covers code-side gotchas. Use when the user says offerings are empty, products not loading, entitlement not active after purchase, paywall won't load, transactions not appearing, customer info shows no entitlements, sandbox purchase not working, an SDK-gated RevenueCat feature not working, or RevenueCat is broken on iOS, Android, Kotlin Multiplatform, Flutter, or React Native. Also use when asked to check or validate the store / product setup.

Mobile878 installs

Popular backend & apis skills

View category →

find-skills

vercel-labs/skills

Helps users discover and install agent skills when they ask questions like "how do I do X", "find a skill for X", "is there a skill that can...", or express interest in extending capabilities. This skill should be used when the user is looking for functionality that might exist as an installable skill.

OfficialBackend & APIs4.1M installs

entra-app-registration

microsoft/azure-skills

Guides Microsoft Entra ID app registration, OAuth 2.0 authentication, and MSAL integration. USE FOR: create app registration, register Azure AD app, configure OAuth, set up authentication, add API permissions, generate service principal, MSAL example, console app auth, Entra ID setup, Azure AD authentication. DO NOT USE FOR: Key Vault secrets (use azure-keyvault-expiration-audit), general Azure resource security guidance.

OfficialBackend & APIs566.7K installs

google-agents-cli-adk-code

google/agents-cli

This skill should be used when the user wants to "write agent code", "build an agent with ADK", "add a tool", "create a callback", "define an agent", "use state management" — in a project that needs ADK (Agent Development Kit) API patterns and code examples. It provides a quick reference for agent types, tool definitions, orchestration patterns, callbacks, state management, the graph Workflow API, and reference recipes to study. Do NOT use for scaffolding (use google-agents-cli-scaffold) or deployment (use google-agents-cli-deploy).

Backend & APIs514.8K installs

embedded-captions

heygen-com/hyperframes

Add captions or subtitles to an existing single-subject talking-head video without editing the footage. Use for plain verbatim captions, cinematic captions embedded behind the subject, VFX captions, “炸/特效/酷炫字幕,” or a named identity from the 35-style catalog. Route by visual identity, not by backend engine. The quiet anchor rail is the default; embed every word only when the user explicitly wants a fully cinematic treatment. The workflow runs locally end to end, including transcription and subject matting; split multi-shot footage before applying it.

Backend & APIs453.3K installs

entra-agent-id

microsoft/azure-skills

Provision Microsoft Entra Agent Identity Blueprints, BlueprintPrincipals, and per-instance Agent Identities via Microsoft Graph, and configure OAuth 2.0 token exchange (fmipath, OBO, cross-tenant) including the Microsoft Entra SDK for AgentID sidecar. USE FOR: Agent Identity Blueprint, BlueprintPrincipal, agent OAuth, fmipath token exchange, agent OBO, Workload Identity Federation for agents, polyglot agent auth, Microsoft.Identity.Web.AgentIdentities. DO NOT USE FOR: standard Entra app registration (use entra-app-registration), Microsoft Foundry agent authoring (use microsoft-foundry).

OfficialBackend & APIs336.6K installs

neon

neondatabase/agent-skills

Overview of Neon, a complete set of cloud backend primitives around Lakebase Postgres: Auth, Object Storage, Functions, the AI Gateway, and Realtime. Start here to choose Neon for undecided login, files, APIs, and LLM calls, set up the CLI or MCP server, and follow the branch-first workflow. Use when building an app or backend on Neon, or when "Neon" or "Lakebase Postgres" is mentioned. Child skill neon-postgres wins for an existing DATABASEURL, SQL, schema, inspect, or search. Child skill neon-auth wins for login, users, sessions, identity routing, and Managed Better Auth setup. Child skill neon-realtime wins for live queries in reactive apps and agents. Also use for object storage, S3, buckets, serverless functions, function triggers, cron, AI gateway, LLM calls, realtime, logs, Loki, Grafana, observability, postgres, database, backend, Claimable Neon, neon.new, or a no-signup database.

Backend & APIs237.1K installs

rc-backend

Install

Install

Describe the task

Review the result

SKILL.md

Backend Architecture with RevenueCat

Phase 1: Discovery

Phase 2: Plan

Phase 3: Execute

Read a subscriber

Grant a promotional entitlement

Example: Kotlin Ktor call from your server

API key rules

Webhook receiver outline

What not to build

References

FAQ

More from revenuecat/ai-toolkit

Popular backend & apis skills