Litelm is a new lightweight library that simplifies the routing and translation of large language model (LLM) calls across various providers. Unlike more extensive frameworks that include proxy servers, caching, cost tracking, and numerous features, litelm focuses solely on the core functionalities: model routing, message format translation, streaming, tool use, and embeddings. The entire codebase is approximately 2,900 lines with just two dependencies, openai and httpx.
Developers can install litelm with pip and optionally include support for providers like Anthropic and AWS Bedrock. The API closely mirrors that of litellm, allowing users to switch with minimal code changes. Litelm supports routing to 19 different providers using a simple "provider/model-name" syntax and works with any OpenAI-compatible endpoint via the api_base parameter.
The library also includes comprehensive error handling by mapping provider errors to litelm-specific exceptions, enabling developers to manage issues such as rate limits, authentication failures, and context window exceedances effectively. Additionally, litelm supports advanced features like streaming responses, embeddings, and function calling with tools.
Litelm has been tested extensively, passing hundreds of local and live tests to ensure compatibility with core routing and formatting behaviors. While still in alpha, it offers a streamlined alternative for developers seeking a minimalistic approach to integrating multiple LLM providers without the overhead of larger frameworks.
This development matters because it provides a more accessible and efficient way to manage multi-provider LLM calls, which can be crucial for applications requiring flexibility and low latency without unnecessary complexity.