What is LiteLLM? A Complete 2026 Guide to Unified AI Gateways

What is LiteLLM? The Unified Gateway for Calling 100+ LLMs with One Consistent Interface If you’re building AI applications in 2026, you’ve probably faced this situation more than once: You start with OpenAI’s GPT models, then want to experiment with Anthropic’s Claude series, Groq’s ultra-fast inference, or perhaps a cost-effective option from DeepSeek or local Ollama deployment. Each provider has its own SDK, slightly different request/response shapes, authentication method, and error handling quirks. Suddenly your codebase fills with conditional branches, custom adapters, and fragile switching logic. When the team grows and you need centralized cost tracking, key management, rate limiting, …