Helicone AI Gateway serves as an open-source alternative to OpenRouter, offering the same features while eliminating markup fees and enhancing cost optimization through automatic routing to the cheapest and most reliable providers. It incorporates built-in observability, providing automatic logging, tracing, and metrics, and offers passthrough billing and the option to bring your own keys for authentication. The migration process from OpenRouter to Helicone AI Gateway involves setting up new API keys, editing code to adjust endpoints, and reviewing requests via the Helicone dashboard. Users should be aware of potential differences in model naming conventions and the handling of provider keys during the transition. Helicone emphasizes cost control and infrastructure simplicity, inviting users to migrate with the promise of reduced expenses and improved error tracking, while also offering support and collaboration opportunities through their Discord community and GitHub repository.