What Is Sandbox Mode?
In sandbox mode:- No real charges are processed
- Stripe test mode is used for all payment flows
- You can create test customers and purchases freely
- All data is separate from production
Testing Your Integration
For MCP Pay
- Add your proxy URL to an MCP client Copy the proxy URL from the MCP Pay section and add it to your MCP client (e.g., Cursor, Claude Desktop).
- Complete the OAuth flow When you first use a tool, you’ll be prompted to sign in. Use your Google or GitHub account.
- Test tool access Call a protected tool and verify it succeeds. Check the dashboard to see the usage recorded.
- Test plan restrictions Try calling a tool that requires a paid plan. You should receive an access denied response with upgrade information.
For SDK Integration
- Use your sandbox API key Your sandbox API key is available in Settings > API Keys. Use this in your development environment.
- Create a test customer Use the SDK or console to create a customer for testing.
- Test paywall protection Call a protected endpoint and verify the paywall check runs correctly.
- Test the checkout flow Trigger a checkout and use Stripe test card numbers to complete the payment.
Stripe Test Cards
Use these card numbers for testing payments:| Card Number | Result |
|---|---|
4242 4242 4242 4242 | Successful payment |
4000 0000 0000 0002 | Card declined |
4000 0000 0000 3220 | 3D Secure authentication |
Testing Checklist
Before going live, verify:- Users can authenticate (OAuth for MCP Pay, your auth for SDK)
- Free plan users can access free tools/endpoints
- Paid tools are blocked for free users
- Checkout flow completes successfully
- After payment, users gain access to paid features
- Usage is tracked correctly in the dashboard
- Quota limits are enforced when exceeded
Next Steps
Once you’ve verified your integration works correctly:- Go Live - Complete onboarding and switch to production