RouteMux is an AI gateway for developers building applications with models from multiple providers. It offers a unified API key and compatible endpoints for OpenAI, Anthropic and Vertex-style requests, allowing applications to connect to a catalog of AI models through a common interface. Developers can use RouteMux to route requests across supported models and manage usage from one service rather than integrating each provider separately. The service uses pay-as-you-go billing, with charges applied to successful requests according to the applicable model and provider rates. RouteMux is intended for teams that want to add or switch among AI models while keeping their application’s connection pattern consistent. Availability, model support and billing conditions may vary by provider and model.