LiteLLM

LiteLLM is an outstanding open-source proxy and SDK that provides a unified interface for calling 100+ LLM APIs using the OpenAI format. Its core value proposition is simplicity: write your code once and seamlessly switch between providers like OpenAI, Anthropic, Cohere, Azure, and many more without rewriting integration logic. The proxy server supports load balancing, fallbacks, spend tracking, and rate limiting " features typically found in paid enterprise solutions. Being completely free and open-source makes it exceptionally accessible for startups and individual developers. The Python SDK is well-documented and straightforward to implement, with the standardized OpenAI-compatible format reducing the learning curve significantly. Key strengths include robust logging integrations, budget management, and model aliasing. Limitations are relatively minor: self-hosting the proxy requires some DevOps knowledge, and edge cases with lesser-known providers can occasionally surface compatibility quirks. For teams managing multi-provider LLM architectures, LiteLLM is nearly indispensable " it eliminates vendor lock-in while providing production-grade routing capabilities that rival commercial API management platforms.