When building LLM-based applications, determining a user's intent before routing a request to a specialized agent or invoking a specific flow is critical. Semantic Router acts as a superfast decision-making layer for LLMs and agents, enabling efficient and reliable routing of requests based on semantic meaning. By using vector embeddings to infer intent, Semantic Router reduces unnecessary LLM calls, offering a leaner, cost-effective approach to understanding user intent. Its potential extends beyond intent inference, serving as a versatile building block for various semantic tasks. The speed and flexibility it offers position it as a strong contender in environments that require fast, real-time decision-making without the overhead of LLMs.