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Requirements

  • Node.js 18+ (or any edge runtime with Web Crypto API)
  • TypeScript 5.0+ (optional but recommended)

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Install

npm install @vgpprasad91/churnkit-sdk

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Set your API key

Add your key to your environment:
.env
CHURNKIT_API_KEY=ck_live_your_key_here
Use ck_test_ keys in development and CI. Test keys are completely isolated from production data.

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Basic setup

import ChurnKit from '@vgpprasad91/churnkit-sdk'

const churn = new ChurnKit({
  apiKey: process.env.CHURNKIT_API_KEY!,
})

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Next.js setup

Create a shared client file so you don’t instantiate on every request:
lib/churnkit.ts
import ChurnKit from '@vgpprasad91/churnkit-sdk'

// Module-level singleton — instantiated once per server process
export const churn = new ChurnKit({
  apiKey: process.env.CHURNKIT_API_KEY!,
})
Then import churn in your Server Actions, Route Handlers, or API routes:
app/api/checkout/route.ts
import { churn } from '@/lib/churnkit'

export async function POST(req: Request) {
  const { userId } = await req.json()
  await churn.event(userId, 'checkout_started')
  // ...
}

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Cloudflare Workers / Edge

The SDK uses only Web-standard APIs (fetch, crypto.subtle) and works on Cloudflare Workers, Vercel Edge Functions, and Deno Deploy with no modifications:
worker.ts
import ChurnKit from '@vgpprasad91/churnkit-sdk'

export default {
  async fetch(request: Request, env: Env) {
    const churn = new ChurnKit({ apiKey: env.CHURNKIT_API_KEY })
    await churn.event('user_123', 'page_viewed')
    return new Response('ok')
  },
}

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Module formats

The package ships both ESM and CJS:
FormatEntry point
ESMdist/index.mjs
CJSdist/index.cjs
Typesdist/index.d.ts
import and require both work out of the box.