Test mode and going live

Build without moving real money, then switch on live payments with confidence.

Every Modem Pay account has two separate worlds: test and live. You build and try everything in test mode. When it works, you switch your keys and go live. Your code doesn’t change.

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What’s different in test mode

	Test mode	Live mode
Keys	sk_test_…, pk_test_…	sk_live_…, pk_live_…
Money	Nothing real moves	Real payments and payouts
Data	Test payments, customers, links, sub-accounts, webhooks	Live ones, completely separate
Webhooks	Your test webhook URL	Your live webhook URL
Needs KYC	No	Yes

The mode comes from the key. A test key only ever sees test data. A live key only ever sees live data. If you get a 404 for something you know exists, check you’re using a key from the same mode.

Use the Test mode switch in the dashboard to see your test data.

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Try your integration

1. Take a test payment

   Follow the Quickstart, or from your terminal:

   npm install -g modem-pay-cli
   modempay login
   modempay transaction init --amount 100
   
2. Receive webhooks on your machine

   modempay listen --forward-url http://localhost:3000/webhook
   

   Every test event is forwarded to your local server, signed exactly as in production. See Modem Pay CLI.

3. Test the unhappy paths

   Cancel a payment, close the checkout, send a webhook your server rejects. Your system should handle each one.

   modempay trigger charge.failed
   modempay trigger charge.cancelled
   

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Go-live checklist

1. Get verified (KYC)

Submit your business documents in the dashboard. You can’t take live payments until they’re approved. The dashboard shows exactly which documents are still missing.

2. Create live keys the safe way

Create a restricted live key for each system, with only the permissions it needs. Add IP allowlists for your servers, and payout limits on any key that can send money. See API keys.

3. Store keys as secrets

Put live keys in environment variables or a secrets manager. Never in your code, your website or your mobile app.

4. Add your live webhook

Add your live webhook URL in the dashboard and store its signing secret. Live and test webhooks have different secrets. Check that your endpoint verifies signatures.

5. Mark orders paid from the webhook

Don’t rely on the customer reaching your return_url. People close tabs. Fulfil orders when you receive charge.succeeded, or after verifying the payment on your server.

6. Use idempotency keys for payouts

Send a unique Idempotency-Key with every payout so a retry can never pay twice.

7. Run one small real payment

Pay yourself 10 GMD on your live site and check the order, the webhook and your balance.

Data never moves between modes. Payment links, customers, coupons, sub-accounts and webhooks you made in test mode need to be created again in live mode.