Skip to main content

​
Configure for Sandbox

Point the SDK to the sandbox API by setting the host environment variable:
All other environment variables (NEXT_PUBLIC_CUBEPAY_MERCHANT_ID, CUBEPAY_API_KEY) use your sandbox credentials from the Grain Dashboard.

​
Run an End-to-End Test

1

Create a payment session

Use your server to create a session against the sandbox API.
2

Open the payment modal

Launch the SDK on the client with the returned session credentials. In sandbox, the SDK connects to test blockchain networks (Sepolia) automatically.
3

Complete the payment

Connect a wallet funded with testnet tokens and approve the transaction. The SDK handles network switching automatically.
4

Verify in the dashboard

Go to the Grain Dashboard and navigate to Transactions. Confirm your test payment appears with the expected status.

​
Test Webhook Delivery

Sandbox webhooks work identically to production. Configure your webhook URL in the dashboard and use a tunneling tool to receive webhooks locally:
Then update your webhook URL in the Grain Dashboard to point to your ngrok URL:

​
Simulate Payment Statuses

Each webhook delivery contains a status field. In sandbox, payments progress through the full lifecycle: Verify your webhook handler processes each status correctly by monitoring your server logs as you complete test payments.

​
Sandbox vs Production

Always test the full payment flow in sandbox before switching to production. Verify that your webhook handler, success screen, and error handling all work as expected.