litelm

litelm is a lightweight Python library that preserves the core routing and message-translation behavior of LiteLLM without its larger proxy and infrastructure layers. It supports provider/model routing, streaming, embeddings, text completions, tool calling, and the OpenAI Responses API. The package mirrors LiteLLM function names and response shapes so existing code can often switch with only an import change. It routes requests across 19 providers and can also target OpenAI-compatible local servers through a custom API base. Async variants are available for the major operations. Provider errors are normalized into a shared exception hierarchy. The project intentionally omits load-balancing routers, caching, budgets, token counting, agents, image generation, and other heavier features.