The sandbox environment lets you test your integration without processing real money. All features work identically to production — the only difference is that no actual payments are made.

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Sandbox vs Production

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Configuration

Use your test API key to automatically target the sandbox:
Use different environment variables for sandbox and production. Never use production keys during development.

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Sandbox modes

The platform offers two sandbox modes. Contact support@simiz.io to switch modes for your project.

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Local simulation (default)

In local simulation mode (default), sandbox payments are simulated entirely locally using magic phone numbers. No calls are made to any external provider. This mode is ideal for development and automated testing as it is fast, deterministic, and requires no provider configuration.

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Provider passthrough

In provider passthrough mode, sandbox payments are sent to the real payment provider’s sandbox environment. This lets you test the full integration, including webhooks and real responses. This mode is useful for validating real provider behavior before going to production.
The sandbox mode is a global platform setting. It only affects projects in sandbox environment — production payments always go through the real provider.

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Test phone numbers

The magic numbers below work in local simulation mode only:

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Orange Money (Cameroon)

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MTN MoMo (Cameroon)

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Wave (Senegal)

Any number not ending with 0001, 0002, 0003, or 0004 will be treated as a successful payment after ~8 seconds.

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Testing webhooks locally

In sandbox mode, webhooks are triggered instantly. To receive them during local development, use a tunnel service:

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Manual webhook testing

From the Dashboard, you can trigger test webhook events manually:
  1. Go to Dashboard → Settings → Webhooks
  2. Click Send Test Event
  3. Select the event type (e.g., transaction.completed)
  4. Verify your endpoint processes it correctly

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Best practices

Test all scenarios. Don’t just test the happy path — verify your app handles failures, timeouts, and edge cases correctly.
  • Test success, failure, and timeout scenarios
  • Verify webhook handling for all subscribed events
  • Use separate environment variables for sandbox and production
  • Test with all supported payment methods
  • Don’t rely solely on API responses — always test webhook flows
  • Use provider passthrough mode to validate the full integration before going to production