> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://corebycarlo.crisp.help/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# How do I test Core Checkout in the sandbox?

# What is the sandbox for?
The sandbox environment lets you test your Core Checkout integration without processing real payments. It follows the same flows as production, with the few differences listed below.

# Your sandbox credentials
Your sandbox credentials are sent to you by email at onboarding. They include:
* **URL:** [sandbox-dashboard.corebycarlo.com](https://sandbox-dashboard.corebycarlo.com)
* **Email:** your developer email address
* **Password:** provided by email
* Once logged in, your test secret key is available under **Developer → Configuration.**

# Your developer space
You can access your developer settings by clicking "**Developer**" in the menu. Two sections are available:

**Configuration** — This is where you set up your API integration. From here you can:
* Open the API Documentation to follow the integration guide
* Retrieve your API key, needed to authenticate your requests
* Configure your Webhooks, the URL where Core sends the result of each payment to your server

**Notifications** — This shows the log of webhook calls sent from Core to your endpoint. For each call you can see the date, the event, the related transaction, the method, the target URL, the response status, the HTTP code, and the duration. Use this to check that your webhooks are being received correctly and to troubleshoot any failed delivery.

### Test cards
👉 [View test card numbers](https://documentation.corebycarlo.com/api-reference/overview/test-cards#test-cards)
* Expiry date: any future date
* CVV: any 3 digits

#### What differs from production
* **Payouts are not simulated.** Sandbox transactions stay in “Transfer pending”. The payout itself can only be observed in production.
* **Charges on a saved card almost always succeed.** To test a charge that requires authentication, use the `force3ds` parameter on the rebill call.
* **Carlo App needs no real account.** The payment page shows Simulate success and Simulate failure controls, which never appear in production.
* **Webhooks are configured separately.** Set your webhook URL in the sandbox, then again in production.

|| ⚠️ **Important** — The sandbox dashboard gives access to the Checkout test environment only. It is separate from the production dashboard.

❓ Having trouble with access? Contact us at [support@corebycarlo.com](mailto:support@corebycarlo.com)