LLMRouter: An Open-Source Library for LLM Routing

Summary

🚀 LLMRouter: An Open-Source Library for LLM Routing ✨ Introduction LLMRouter is an intelligent routing system designed to optimize LLM inference by dynamically selecting the most suitable model for each query. To achieve intelligent routing, it defines: 🚀 Smart Routing: Automatically routes queries to the optimal LLM based on task complexity, cost, and performance requirements. 📊 Multiple Router Models: Support for over 16 routing models, organized into four major categories—single-round routers, multi-round routers, agentic routers, and personalized routers—covering a wide range of strategies such as KNN, SVM, MLP, Matrix Factorization, Elo Rating, graph-based routing, BERT-based routing, hybrid probabilistic methods, transformed-score routers, and more. 🛠️ Unified CLI: Complete command-line interface for training, inference, and interactive chat with Gradio-based UI. 📈 Data Generation Pipeline: Complete pipeline for generating training data from 11 benchmark datasets with automatic API calling and evaluation. 📰 News 🚀 [2025-12]: LLMRouter is officially released - ship smarter 🧠, cost-aware 💸 LLM routing with 16+ routers 🧭, a unified llmrouter CLI 🛠️, and a plugin workflow for custom routers 🧩. 🔗 Links 🧭 Supported Routers Single-Round Routers Router Training Inference Description Tutorial knnrouter ✅ ✅ K-Nearest Neighbors based routing 📖 svmrouter ✅ ✅ Support Vector Machine based routing 📖 mlprouter ✅ ✅ Multi-Layer Perceptron based routing 📖 mfrouter ✅ ✅ Matrix Factorization based routing 📖 elorouter ✅ ✅ Elo Rating based routing 📖 routerdc ✅ ✅ Dual Contrastive learning based routing 📖 automix ✅ ✅ Automatic model mixing 📖 hybrid_llm ✅ ✅ Hybrid LLM routing strategy 📖 graphrouter ✅ ✅ Graph-based routing 📖 causallm_router ✅ ✅ Causal Language Model router 📖 smallest_llm N/A ✅ Always routes to smallest model 📖 largest_llm N/A ✅ Always routes to largest model 📖 Multi-Round Routers Router Training Inference Description Tutorial router_r1 LINK ✅ Pre-trained Router-R1 model ...