LiteLLM is an open-source library and proxy server that provides a single, unified interface to call over 100 large language model providers using the OpenAI request format. It solves the integration complexity developers face when their applications need to work with multiple LLM providers, each with their own API format, authentication, and response structure. LiteLLM standardizes all of this behind one consistent interface, allowing developers to switch between providers with a single configuration change.
The LiteLLM Proxy Server acts as a production-grade API gateway with centralized authentication, multi-tenant cost tracking per project and user, and real-time monitoring of all API calls. It supports automatic retries for failed requests, load balancing across multiple provider endpoints, and virtual API keys for secure access control. The Python SDK provides a simple completion function that works identically across OpenAI, Anthropic, Vertex AI, Bedrock, Azure, HuggingFace, Ollama, and dozens more providers, standardizing all responses to the OpenAI format. An admin dashboard UI offers visual monitoring and management of the entire gateway.
LiteLLM is designed for engineering teams and platform builders who need to manage LLM usage across multiple providers and projects at scale. It is commonly used as the LLM gateway layer in enterprise AI platforms, enabling centralized cost control, provider failover, and usage analytics. The library integrates with observability tools like Langfuse and supports deployment on AWS Marketplace for enterprise environments. LiteLLM competes with OpenRouter as a multi-provider gateway, differentiating itself as a self-hosted, open-source solution that gives teams full control over their LLM routing, logging, and cost management infrastructure.
