Quickstart

Install an SDK, model a product, and validate your first purchase.

This guide takes you from zero to a validated purchase. It should take about 15 minutes.

You'll need a CashSDK workspace. Create one for free — free up to $5,000/mo in tracked revenue.

1. Get your API keys#

Every workspace has two kinds of keys:

Key	Prefix	Used by
Publishable	`pk_live_…` / `pk_test_…`	Client SDKs (safe to ship)
Secret	`csk_sk_…`	Your backend, the CLI, and the MCP server

Find them under Settings → API keys in the dashboard, or read more in Authentication.

2. Install the SDK#

swift

// In Xcode: File → Add Packages…
// https://github.com/cashsdk/cashsdk-ios
import CashSDK

kotlin

// build.gradle.kts
dependencies {
  implementation("com.cashsdk:cashsdk-android:1.0.0")
}

bash

npm install @cashsdk/react-native

bash

flutter pub add cashsdk

bash

npm install @cashsdk/web

3. Configure on launch#

Initialize CashSDK once, as early as possible, with your publishable key.

swift

import CashSDK

CashSDK.configure(apiKey: "pk_live_...")

kotlin

import com.cashsdk.CashSDK

CashSDK.configure(apiKey = "pk_live_...")

import { CashSDK } from "@cashsdk/react-native";

CashSDK.configure({ apiKey: "pk_live_..." });

4. Create a product#

Model a subscription in the dashboard, or create one from the terminal with the CLI:

bash

cashsdk catalog add \
  --product pro_monthly \
  --entitlement pro \
  --type subscription

Prefer to let an agent do it? Point Cursor, Claude Code, or Codex at the CashSDK MCP server and ask it to set up your catalog.

5. Show a paywall and purchase#

Fetch offerings, present your paywall, and complete a purchase. CashSDK handles the native store interaction and validates the receipt server-side.

swift

let offering = try await CashSDK.offerings()
let result = try await CashSDK.purchase(offering.monthly)

if result.entitlements["pro"]?.isActive == true {
  unlockPro()
}

kotlin

val offering = CashSDK.offerings()
val result = CashSDK.purchase(offering.monthly)

if (result.entitlements["pro"]?.isActive == true) {
  unlockPro()
}

6. Verify server-side (optional)#

Your backend can check entitlements or validate a receipt directly:

bash

curl https://api.cashsdk.com/v1/receipts/validate \
  -H "Authorization: Bearer csk_sk_..." \
  -H "Content-Type: application/json" \
  -d '{ "platform": "apple", "receipt": "MII...", "app_user_id": "u_812" }'

Next steps#

Build a paywall

Design and publish paywalls over the air.

Handle webhooks

React to purchases and renewals in real time.

Entitlements

Model access the right way.

Go to production

Test in sandbox, then ship.