> For the complete documentation index, see [llms.txt](https://docs.drizz.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.drizz.dev/getting-started/drizz-desktop-app/drizz-desktop-app-setup/download-and-installation/preflight-health-and-connectivity-check.md).

# Preflight Health & Connectivity Check

## Why Drizz Runs a Connectivity Check

Before initiating any test execution, Drizz performs a **preflight connectivity check** to ensure the entire testing environment is fully operational and reliable.

This step validates that all critical dependencies required for deterministic automation are reachable and healthy, including:

1. **Deep link resolution** to confirm seamless app-to-platform communication
2. **Authentication services (Auth0, OpenID, JWKS)** to ensure secure and valid session handling
3. **Core backend services** such as Device Management, Test Management, and WebSocket gateways
4. **Network integrity** including DNS resolution, proxy routing, and HTTPS availability

By verifying these components upfront, Drizz ensures:

1. Tests don’t fail due to infrastructure or network issues
2. Real-time device communication is stable
3. Authentication and authorization flows are correctly configured
4. Test execution starts only when the system is fully ready